Astrophotography on a Budget by Martin Cohen

Many years ago, before digital photography revolutionized the medium, taking a beautiful shot of the Andromeda Galaxy (M31), or even a detailed image of the moon, showing its many craters, rilles and mountains would only be possible if you had a large wallet and access to highly specialized equipment and techniques. For the average amateur astronomer it was entirely out of reach.

With high-end telescopes now being mass produced, new optical designs and most importantly, the digital camera in combination with brilliant new software solutions that dramatically increase the quality of the images, the popularity of astrophotography has increased exponentially over the past two decades. What was virtually impossible twenty years ago is now available to anybody with a passionate interest and willingness to spend long hours perfecting the art of celestial imaging.

Polarex (Unitron) 50mm Achromatic RefractorI was thirteen when I received my first telescope, a Polarex (Unitron) 50mm achromatic refractor. It was a present from my maternal grandmother and I remember clearly how impressed I was with its beauty and quality. Both my parents were supportive of my new hobby, but whereas my dad would take a quick look at Saturn and continue whatever he was in the midst of, I could not get enough of it – I spent hours and hours behind my little telescope, never tiring of the ever changing views that the moon would offer, the rings of Saturn and the four largest moons of Jupiter.

DSLR Eyepiece ProjectionI soon began taking pictures through my scope, first by simply holding my camera behind the eyepiece, and later with an inexpensive Russian reflex camera (Zenith B), using a special adapter for eyepiece projection (see photo). This technique uses the same eyepiece you look through to project an image on the film or sensor of your camera. It is a great way to shoot the moon and the planets.

By that time, I had also built my first darkroom and I started to experiment with specialty film developers (like Acufine and Diafine) to push my Kodak Tri-X film to ISO 1600. The results were actually quite decent (see samples), considering the fact that it was only a 50mm refractor without motor drive or anything. I exposed the film by opening the camera shutter and then moving a black piece of cardboard in front of the telescope, briefly uncovering the lens, so vibrations from shutter and mirror would be minimized. I cherish that little telescope to this day and last year completely refinished its beautiful wooden case (which over half a lifetime was pretty badly beaten up).

Fast forward to 2011. I have moved from my native Amsterdam, Holland, to the west coast of the United States, where I make a living as a photographer. My passion for the stars was lying dormant for a long time. Then, about two years ago, the itch to take some new photos of the moon (37 years after those romantic days of Tri-X developed in Acufine!) got ignited when I won a bid on Ebay for a Meade 90mm GoTo refractor at a great price.

Very quickly, I discovered that my Photoshop skills were a real asset in getting the maximum out of this modest telescope. After a few efforts, using the same eyepiece projection techniques that I used as a kid in Amsterdam, I was able to come up with very sharp images that looked as good as some of the shots I had seen by the “big boys” in the early seventies– shot with a scope I had bought for less than $100! (click here for samples)

In March of last year, I bought a large Dobsonian (10-inch mirror, f/5), brand new on Ebay, again for very little money. I was curious to see what the larger aperture would do for my moon shots and indeed, without any tracking, using a wireless remote for the shutter and flipping up the mirror of my Nikon (to minimize vibrations), I got some very detailed images.

There are several myths regarding equipment for astrophotography that are still going around:


MYTH #1: in order to take sharp photographs of the moon, you need an expensive scope with motor drive, to track the motion of the moon along the night sky.


Not so. At an exposure of 1/30 sec, the movement of the moon along the sky is less than 0.5 arc second, well below the resolution of most amateur instruments. Shooting at ISO 400 to ISO 800, which I consider the best range for the moon, there is enough leeway to extend your focal length all the way to f/45; if your lens or mirror has a 10cm (4”) diameter, the effective focal length can be as long as 4.5 meter (15 feet). It is best to shoot when the moon is high in the sky, otherwise turbulence increases and clarity suffers.

Here are some rough exposure guidelines for the moon:

Crescent Moon f/32 ISO 800 1/30 sec
First and Last Quarter f/45 ISO 400 1/30 sec
Full Moon f/45 ISO 400 1/125 sec

 

Moon 04/19/2010 by Martin CohenPersonally, I like to use eyepiece projection, but a good Barlow works just as well, especially with telescopes that already have a long focal length. The pixels in the sensor of your DSLR (= digital single lens reflex camera) will not be able to register the finest detail of your telescope if you shoot prime focus, particularly with the shorter and faster type Newtonian telescopes. Of course, you cannot frame the whole moon using those long focal lengths, so if your goal is to show the full disc, you have to piece them together from the detail shots in Photoshop, like I did with the photograph to the left (click on photograph to see more detailed samples, shot with a 10-inch Dobsonian).

 

 

In summary, taking photographs of the moon is relatively easy. All you need is:

  • a simple telescope with a mount that provides good support
  • a digital camera, preferably a DSLR (a used Canon EOS is fine)
  • an eyepiece projection adapter to attach your camera to the telescope
  • a so-called T-ring that is specific to your camera
  • a wireless remote to trigger your camera shutter

Look around for the best deals on telescopes- here is a fantastic one at Optics Planet: Celestron Powerseeker 80 EQ.

The T-rings are around $15, like this one for a Canon EOS: Celestron T-Ring for Canon EOS Camera.

And here is a very nice wireless remote, available for a multitude of cameras (here for the EOS): Wireless Remote Switch. This one is compatible with Canon 1D/1DS, EOS 5D/5D Mark II, 50D, 40D, 30D, 20D, 10D, 7D, and D60. Also, here is a super inexpensive one that only works for selector models that have an IR receiver built in: IR Wireless Remote Control.

Let’s cover the process step-by-step: first, you place your eyepiece in the camera adapter (best to start with a 20 or 25 mm eyepiece since it gives you a wider field) and then attach it to the camera and the telescope. Set the camera to ISO 400 or 500 for half moon – which shows the most craters. If the moon is almost full, ISO 100 or 200 is plenty and for a small crescent, ISO 800 works well. Now focus your telescope as precisely as you can through the viewfinder of, even better, using LiveView on the display screen. In order to avoid a blurry image caused by the shock of the mirror, it is advisable to lock the mirror before taking the shot. You can experiment with exposures between 1/15 and 1/60 of a second in manual mode. I don’t recommend using automatic exposure, but sometimes it works quite well. Using a wireless remote will help keep everything steady, since touching the camera can cause vibrations.

If preferred, you can shoot in prime focus or with a Barlow lens by connecting the front part of the adapter directly to your camera (using the T-ring). So you leave the part with the eyepiece out altogether. That way, the exposures will be even shorter and you can easily capture the whole moon instead of a partial disc. It takes practice to get great results but you will be surprised how many craters will show even in your very first attempts.

Deep Sky Photography

With my newly reawakened interest for the night sky, it was only logical that I wanted to extend my efforts to Deep Sky objects as well as the planets. But how on earth was I going to do that with my very limited equipment? By now, I had seen gorgeous photos of nebulas and star clusters, taken by experienced amateurs with apochromatic refractors and high-end Newtonians or Schmidt-Cassegrain systems (the difference between these telescopes will be explained later in the article). They always used sturdy equatorial mounts with precise motor drives to track the night sky and achieve pinpoint stars. I was fairly convinced that I would need to invest some serious money in order to produce similar results.


MYTH #2: in order to photograph nebulas, star clusters and other Deep Sky objects, you need an equatorial mount, with motor drive and a guide scope, to allow for sufficiently long exposures.


I need to be perfectly clear: if you can afford a good equatorial mount with precise tracking capability, there is no question that your images will benefit from the more sophisticated equipment. However, these days it has become entirely possible to create powerful images of our amazing universe with fairly basic means, like a simple GoTo Alt-Az mount.

Here is my list of imperatives to reach good results without the big bucks:

  • A dark site, far away from city lights
  • A fast lens or telescope (f/5.6 or faster)
  • A tracking mechanism, Alt-Az is fine, equatorial is better
  • Deep Sky Stacking software
  • Basic knowledge of Photoshop
  • A good DSLR, allowing settings from ISO 400 to ISO 3200
  • Patience and the willingness to spend many hours in the dark

The Dark Site

Most of us live either in or close to the city and with a few exceptions (notably the moon and planets), there is really not that much to see, let alone to photograph. On a clear night, we may catch a glimpse of the brightest Deep Sky objects like the large Orion nebula (M42) or the Andromeda Galaxy (M31); M13 in Hercules may offer a pleasant view, same with the Pleiades (M45). But compared to the wealth of objects that are visible once we get away from the big cities (even with a simple pair of binoculars), the skies above our living quarters usually offer remarkably little. For Deep Sky photography, you will be much better off with a small telescope at a truly dark site than a fancy 10-inch Schmidt-Cassegrain in the middle of a large city. Many expensive telescopes sit and gather dust for exactly that reason: their well-to-do owners never really took the time and effort to get the maximum out of their instrument.

A dark sky will allow for longer exposures and render images with higher contrast and much better detail. If you are in a big city, just try pointing your digital camera at the night sky (on a tripod) and open the shutter for a minute or so at f/4. Even at a moderate ISO 400, chances are that what looks like a fairly dark sky to your eye ends up being completely washed out in the photograph. Under those circumstances, there is no way to get a good image of your targeted fuzzies. Investing in a good quality Light Pollution Filter helps overcoming the problem a bit, but nothing beats the splendor of a truly dark site.

The Equipment


MYTH #3: you get what you pay for.


This is common wisdom, and when it comes to telescopes, it is entirely flawed. I know people who spent a small fortune on a telescope that they never really understood and were unable to work with. Years later, they’d be lucky if they could sell it on Ebay for a quarter of what they paid. It’s entirely possible to get good results from inexpensive equipment. More money does not always mean a better telescope. Often, it means a heavier and more complex instrument, so serious research is strongly recommended when buying one. What makes all the difference is knowledge and experience: knowing the constellations, understanding the differences between refractors, Newtonians and Schmidt-Cassegrain systems, spending lots of time studying the night sky… The truth is that a modest instrument in the hands of an expert will yield far better photographic results than a very advanced telescope in the hands of a novice.

Here is a list of the most basic equipment you will need:

  • A small telescope with a short focal ratio (I used an inexpensive 80mm f/5 short-tube refractor for most of my Deep Sky images, you can often find them on Ebay for well under $100)
  • A mount with a motor drive to track the stars (preferably equatorial, but up to 20 second exposures can be done with an Alt-Az mount)
  • A DSLR camera (I like the new 24MP Nikon 3200 and the Canon EOS series; for $700 or less you are in business, $300 if you buy used )
  • A T-adapter (prime focus) to connect the camera to the telescope ($25 or less)
  • A T-ring specific to your camera ($15 or less)
  • A wireless remote to trigger your camera shutter (keep vibrations to a minimum for $20 or so)
  • A computer with stacking software (Deep Sky Stacker, downloads for free on the Internet) and Photoshop, any version is really OK

Most smaller telescopes are sold with a mount – for a novice, the GoTo capabilities on the inexpensive Alt-Az mounts will make finding the objects in the sky a lot easier. I highly recommend Cloudy Nights classifieds for used astro-equipment. Ebay is another great source.

The Shooting Process

I always prefer to set up my gear before sunset, when there is still a fair amount of light to see what I am doing. If you are lucky to live under dark skies, then you can shoot from your own backyard, but most of us will need to drive out for at least 20 to 30 minutes to be away from city lights. An open parking lot or campground, preferably with picnic tables is ideal. Make sure to bring some flashlights with red foil or gel over the front (red light does not affect your night vision, whereas white light does).

Set everything up in the most organized way, so you will not have to look for things later. If you are using an equatorial mount, you need to align it to the North Star (Polaris) to make sure the polar axis (also called right ascension) is parallel to the rotation axis of the Earth, see diagram.

Equatorial Mount

A compass is very helpful in finding your general orientation before it is dark enough to see the stars. For most GoTo systems, you will also need a compass to point your telescope north at the start of your alignment. It is a good idea to know in advance which celestial objects you are going to photograph that night. Studying the night sky beforehand is essential and I highly recommend using planetarium software like Stellarium (free download). There are also many great books available, like Night Sky Atlas by Robin Scagell, for only $10 to $15 plus shipping on Amazon.com.

While it is still light, you attach the camera to the telescope, using the T-adapter for shooting in prime focus. You can use a faraway mountain or something near the horizon to focus on. If the moon is visible, that’s even better. If your camera has LiveView, you can zoom in on the display, that makes precise focusing much easier. Once you are in perfect focus, you lock the focuser with the lock screw. (In case your telescope does not allow locking the focuser, all you can do is tighten the mechanism so it feels pretty stiff and will not move by itself).

We will be needing so-called flat frames in the final processing of our images and this is a great time to shoot them. No optical system is perfect and especially with cheaper telescopes, the corners of your image are less bright than the center. A flat can be an image of an empty part of the sky, that shows nothing except the difference in brightness. Point your scope up well before any stars appear and take a few shots on automatic, ten is more than enough. The stacking software we use later will be using these images to subtract from the actual photographs, thereby correcting the differences in brightness. You can also put a white T-shirt over the front lens and shine a light though it, but I prefer this method.

Once it is dark enough to start shooting (usually about an hour or so after sunset), we need to find the Deep Sky objects on our shooting list. Locating those faint nebulas in the sky that look so rich and detailed in photographs is not easy at all, especially in the beginning. A good pair of wide-angle binoculars (7×50 or 7×35) is a fantastic tool to bring them a little closer and get a better idea of their position. Once you found them, it will not be too hard to center them in your telescope, using a good finder scope. You will definitely need a motorized tracking mechanism to keep them centered. Of course, if you are using a GoTo mount, it will find the object for you. It certainly makes life a lot easier, but it also creates a dependency; I am a strong advocate of learning the night sky and finding objects based on the position of the stars.

For Deep Sky objects, I usually set my camera to ISO 1600. You can go higher, but it adds more noise to the image. I like to shoot in RAW-mode, but setting your camera to hi-res JPEG files will work just fine.You will need to take a lot of exposures of the same image, at least ten or fifteen, which will all be stacked later in the Deep Sky Stacker software. The more exposures you take, the less noise will appear in the final processed image, which makes it possible to get more detail. If you use an Alt-Az GoTo mount, the maximum you can expose for is about 20 seconds before the stars will begin to show trails. With a simple (unguided but motor driven) equatorial mount you can go up to 30 sec or even one minute, especially if you are using your camera with a telephoto lens. The longer the focal length, the more difficult it will be to get pinpoint stars. Precise polar alignment makes a real difference.

At the beginning and end of each sequence of exposures (individual exposures are called subs), you need to shoot the so-called dark frames. Deep Sky Stacker will use these files to correct the inherent flaws of your camera sensor (the dark signal), which also depends on the outside temperature. A dark file is shot with exactly the same exposure as your subs, only with the lens covered. Usually 6 dark frames at the beginning and six at the end is plenty; if you need to move fast then three or four will do.

So by the end of our shooting session we will have a dozen flat frames (shot early in the evening), all our picture files (or subs), and a series of dark frames for each object we photographed. Finally, we need to create the bias frames by shooting ten or twelve shots at the very shortest exposure our camera allows (same ISO setting as the picture files), again with the lens covered. Take good notes about which frames are which, since you can’t tell much from a black image! All these files will be combined in Deep Sky Stacker to produce our final shots.

Images taken with 80mm f/5 short-tube refractor, focal length 400mm

These photographs were taken with my 80mm Rokinon short tube on my Meade Alt-Az mount, 12 to 15 subs at ISO 1600, exposed at 15 or 20 seconds, stacked in Deep Sky Stacker.

Click on image to see larger version:

 

Images taken with Nikon D300 with 180mm ED lens on an EQ-1 mount with motor drive

For these shots, the subs were taken at 30 sec each at ISO 1600, usually about 15 to 20 exposures per photo. Stacked in Deep Sky Stacker, further processing in Adobe Photoshop CS3.

Click on image to see larger version:

Processing

Deep Sky Stacker can be downloaded for free at deepskystacker.free.fr/. After loading the images complete with flat frames, dark frames and bias frames, we simply let the software do its amazing job. The image file we end up with will have most of the noise removed and probably show more detail than the single frames we started with. However, the image is far from done. It is only in the final processing that an image truly comes to life. To achieve that, we need a velvety black background, pinpoint stars (at least the small ones), rich color and plenty of detail in the nebulosity. I am amazed at the amount of online images that could be so much better if the techniques I am about to describe would have been applied to them!!

Here is an example of a very nice shot of the Horsehead and Flame nebulas, posted by an experienced astro-photographer who used Nebulosity 2 and Photoshop 4 to process the image:

Horsehead and Flame Nebula

Notice the wonderful detail (shot with a Astro-Tech 65mm f/6.5 wide-field apochromatic refractor and a $2000 S-BIG CCD camera, a beautiful set-up, with a total exposure of almost ten hours in five-minute increments).

However, the photo lacks a bit of contrast, the sky is not really black and the H-alpha clouds are pink instead of red. Also, in several places the gas clouds look yellowish and muddy.

Additional processing and sharpening in Photoshop reveals a stunning image:

Horsehead and Flame Nebula After

Of course, it’s never perfect: some of the faintest nebulosity got lost here, so I could probably start again from scratch and try to keep all the thin filaments. The main point is that the final processing in Photoshop can make all the difference between a good photograph and a great one. Personal taste is an important factor, too: many astro-photographers prefer their skies dark but not quite black.

So which are the basic Photoshop techniques to bring out the best detail and color in your astro-photographs?

Let’s start with an example of my own Deep Sky images, the Orion star field.

Using an f/2.8 telephoto lens with a 180mm focal length on my Nikon D300, taking about 25 exposures of 30 seconds each at ISO 1600 (total exposure 12.5 minutes) gave me the following file after stacking the images in Deep Sky Stacker:

Deep Sky Stacker Processing

Nothing too exciting: we barely see the Flame nebula and the Horsehead nebula is completely absent. The background is a bit muddy and has a reddish brown cast. More than anything, it does not seem to show very much! One would almost discard the photograph as a failed attempt. This is typical of a stacked but unprocessed image. It holds much more information than you can see.

The first thing to do is to increase the contrast and improve the color. You can play with the Levels (Ctrl-L) and the Curves (Ctrl-M), but personally, I like to start with Brightness/Contrast (Image-Adjustments-Brightness/Contrast – top of the menu). I just keep sliding the cursors to the right until the hidden details start showing. If your version of Photoshop has Shadows/Highlights built in (also under Image-Adjustments), then moving those cursors can give you a good idea of the information in the file. The trick is to keep making the image brighter and then darkening the background by adding contrast.

Another helpful way of doing this, while at the same time removing a color cast, is using Color Balance (Ctrl-B, also under Image-Adjustments). At the bottom of the color balance window, where it says Tone Balance, click on Shadows. It will light up in blue. Then you choose the color you need to remove, in this case mostly red. By moving the red cursor to the left (adding cyan), not only do you fix the color cast, but at the same time the background becomes darker and more contrasty. I also moved the yellow cursor a little bit to the right (adding blue). It needs to be done subtly, but it greatly improves the overall appearance.

Finally, I go to Hue/Saturation (Ctrl-U, also under Image-Adjustments) and move the saturation cursor to the right, adding depth and color. Again, don’t overdo it; go as far as you can before it starts looking a bit artificial.

Photoshop Processing

The new image is much better: color and contrast have improved and there is lots of nebulosity showing where before there was nothing. Even the Horsehead nebula is starting to show. A lot of people would stop here and many times I have done so myself. Yet, we can push the envelope even further.

One of my secret Photoshop weapons comes into play here: the Lasso tool. I always use it with a feathered edge, which you can set at the top of the menu in a little window to the left where it says Feather (after you click on the lasso tool). Depending on the size of the area you want to affect and the size of your original file you can set the feather anywhere from 3 px (for a tiny area) to 250 px (for a very large area). Usually, it will be anywhere from 10 to 50 pixels.

There is no way a regular DSLR could show a detailed Horsehead Nebula with these kind of short exposures (30sec x 25). So it’s time to get creative. In order to bring out the faint detail we have to isolate the nebula and work locally. It helps to look at a great shot of the object done with more advanced equipment, so we get a good feeling where to draw the lasso. Once we have defined the area with a nice feathered edge, we can accentuate the nebulosity by going to Levels (Ctrl-L) and moving the central cursor to the left, opening up the shadows. If the effect gets too muddy, we go to Brightness/Contrast and add contrast to darken the background. Now we can also play with the color: go to Color Balance (Ctrl-B) and add some red, maybe even a hint of magenta. We can further intensify the color by adding saturation (Ctrl-U) until it looks just right. Again, don’t push it too far!

Applying this technique locally for the Flame Nebula as well as the Great Orion Nebula to the right has brought out details that were completely invisible in the first stage. I used a little sharpening and increased the overall contrast a hair more to reveal the final image:

Orion Star Field Final
Click on the photograph to see the hi-res version

Two factors could significantly improve this photograph:

1. Using a modified DSLR with a much higher sensitivity in the H-alpha region would make the nebulas stand out even more clearly (more info at Hap Griffin’s website)

2. Using longer exposures (3 to 5 minutes each) would show a richness of detail that is impossible to get in thirty seconds. To further improve contrast at long exposures, a Light Pollution Suppression (LPS) filter is highly recommendable under less than perfectly dark skies.

Of course, we would be leaving the low-budget area here and move into a more sophisticated field of astrophotography. Longer exposures require a very sturdy equatorial mount with precise tracking and a high quality auto-guider. That will be my next stage of exploration.

Fun and Easy First Steps

If you are new to astro-photography, there are so many easy ways to begin. With a simple digital camera on a tripod, it is possible to take some very nice photographs of the stars. You need a camera that allows manual settings so you can use time exposures and keep the shutter open for at least thirty seconds. First set the focus of the camera to infinity. Then open the aperture all the way (usually to f2.8 or f3.5 – the smaller the number the wider the aperture). Point the camera in wide-angle mode to a bright part of the sky with lots of stars. Of course, you want to be far away from city lights, otherwise the results will be disappointing. Set your sensitivity to ISO 400. If you go too much higher (ISO 800 and up) the image may be noisy, especially on the less expensive cameras.

Now just open the shutter for 10 seconds, 20 seconds and 30 seconds. You can see how long you can expose before the stars become small trails instead of points. The rotation of the Earth causes the stars to move, so with a static tripod the exposure can’t be very long.

However, if you point the camera North and leave the shutter open for an hour or more (you need a very dark site to do that, otherwise the image blows out completely), the star trails will form beautiful concentric circles. Keep the ISO settings fairly low (ISO 200 or less) and you can even stop down a bit (to f5.6 or f8), so the background remains dark. It is surprising how much light a simple digital camera can gather in a few minutes.

If you own a DSLR with a fast lens (f/2 or faster), you can really get some good results without any tracking. All you need is a dark site and a sturdy tripod. With relatively short exposures you can photograph the constellations and even see some of the brightest nebulae and star clusters. If you use a wide-angle lens, pointed at the Milky Way in summer, you can expose up to 20 seconds before the stars show any trails. At ISO 1600, you can gather a wealth of information, especially if you take ten or more exposures and use Deep Sky Stacker to process the images. Even ISO 3200 can be used, because the stacking software will considerably reduce the noise.

The following images were taken very recently with a Nikon D300 at ISO 1600, using my 85mm f/1.8 lens (shooting full open). I exposed for only 4 seconds, taking about a dozen exposures stacked in Deep Sky Stacker, then further processed in Photoshop CS5. I was pleasantly surprised to see how many stars are visible of the Double Cluster in Perseus, as well as the Pleiades (M45), and how well the Andromeda Galaxy (M31) and the Great Orion Nebula (M42) are coming through. Even the Flame Nebula in Orion’s belt is showing (barely, but still!). The shot of Orion was composed of three images since my 85mm lens is not wide enough to show the full constellation. No tracking here, just a sturdy tripod!

Click on image to see larger version:

        

Piggy-back Photography with a Telescope

If you have a small telescope, especially one that has a tracking mechanism, you can mount your camera to the telescope and use the scope to track the stars while the shutter of the camera is open. This way, you can expose a lot longer before seeing star trails, especially with an equatorial mount. Because the axis of an equatorial mount is parallel to the axis of the Earth, it completely compensates for its rotation once your tracking and polar alignment are precise.


Overview of telescopes

There are many different kind of designs for telescopes, but most amateur telescopes fall into one of three categories:

  • Refractors
  • Reflectors
  • Catadioptric systems

 


Refractor

Refractor Telescope

A refractor is a simple tube with a lens (the objective) in the front and another lens (the eyepiece) in the back. Usually the front lens consist of two pieces of glass, each with a different breaking index to control false color (chromatic aberration). Those are called achromatic objectives. The best corrected and most expensive refractors are called apochromatic: they often have an objective that consists of three and sometimes even four elements. For astrophotography they are ideal, but again, they aren’t cheap.


Reflector

A reflector uses a concave primary mirror instead of a front lens:

Reflector Telescope

A smaller secondary mirror under a 45 degree angle reflects the light outside the tube where an eyepiece can catch the focus point. This design is called the Newtonian telescope, invented by Sir Isaac Newton. A variety is the Dobsonian telescope, which is exactly the same design on a very simple and inexpensive mount. Because of the relatively simple construction and the large mirror size, these are great instruments for exploring Deep Sky Objects such as nebulas and distant galaxies, since they gather a lot of light.


Catadioptric

Finally, the catadioptric systems, such as the Schmidt-Cassegrain telescopes or the Schmidt-Newtonian telescopes, use a glass corrector plate in the front of the tube.

These are complex optical systems that have become affordable since they were mass produced by companies like Celestron, Meade and Orion. Their short build and large light-gathering capabilities make them ideal for observations of the moon and planets, as well as Deep Sky Objects. Since their effective focal length is rather long, they would not be my first choice for photographing faint nebulas and galaxies, but for imaging the moon and planets they are absolutely wonderful.


Martin Cohen with New Telescope!Martin Cohen is a professional photographer and amateur astronomer in Santa Monica, California.

Martin Cohen’s Astrophotography Website

Martin Cohen Photography

Photos of the Moon

Photos of Havana, Cuba

See Martin’s tutorial on AstroPhotography Tonight: Creating Seamless Mosaics in Photoshop.

 

 

 


Recommended websites:

Stellarium

Stellarium is planetarium software that shows exactly what you see when you look up at the stars. It’s easy to use, and free to download. A great way to learn about the stars and prepare for nightly observations.

Cloudy Nights

Cloudy Nights is a wonderful site with great forums, articles, equipment reviews and classified ads for new and used equipment. It is free, all you need to do is sign up online for membership.

Deep Sky Stacker

Deep Sky Stacker is a revolutionary free software for serious astro-photographers, that will enable you to stack and align many exposures of a nebula or galaxy, to maximize the signal to noise ratio. Try it out!!

George Kolb Astrophotos

George Kolb is one of the many experienced astro-photographers in the USA whose gorgeous images show you what is possible with lots of dedication and high-end equipment.


Comments

  1. Great article, very informative. It’s amazing the great shots that can be taken with very modest equipment. I never would’ve thought that one could do photographs of space with something as short as an 80mm or 180mm camera lens.

  2. Bruce Bartle

    Enjoyed the mini tutorial very much Mr. Cohen. I’m just starting out, so your step by step explanations are very helpful. I have bookmarked this page for future reference.

    Thanks again!

  3. I’m still new to astronomy, but found your article very helpful. I have a Nikon DSLR and a 5″ refractor on a ALT-AZ Goto mount. So many people said I need to spend thousands if i wanted to photograph the night sky, Obviously i don’t! Thanks for the great article, it’s now added to my favourites folder.
    When we have a clear sky i’m certainly giving it a go.

    Thanks

  4. Thomas D. McManus

    I am new to Astronomy and I need some help. I am thinking of buying a CanonEOS Rebel T3i or the T3i camera with lenses. Would this be better than the Nikon D5100 for Astrophotography? The telescopes that I am thinking of getting are; !) the iOptron SmartStar-e-MC90 Astro Blue 90mmMaksutov-Cassegrain OTA, with Altazimuth “cube” mount, #8403 with GoToNova Controller and with their heavy duty S;Steel Tripod thai is sold at Adorama. What is your thoughts? 2) more expensive, the Celestron Nex-Star 127mm SLT Maksutov-Cass. computerized Telescope with GoTo mount,skyalign, fully computerized mount,s.s.tripod.item #cele376 at Telescopes.com. This is more expensive but likely better than the other. I live in Concepcion, Chile, cameras and Telescopes are more expensive than in the USA. I plan to buy in the USA when I travel up.

  5. Hi Thomas,

    I have used a Nikon D3100 for astrophotography and it works well. I don’t know the D5100 from experience, but I do know that the EOS rebels are very popular for astro-photography.

    Definitely, the Nexstar 127 will be a really wonderful telescope for $500. Keep in mind that it’s a great telescope to photograph the moon and the planets but NOT for nebulas, galaxies, etc.
    For that, you need a much faster scope (I recommend f/5 or faster) and preferably an equatorial mount (see my article). You will also need a lot of patience and work on understanding polar alignment and precise tracking. It is difficult and very time consuming!

    Here is an inexpensive one you could start with (tripod is soso, but the scope is nice):
    http://www.telescopes.com/telescopes/reflecting-telescopes/celestronastromaster130eqreflector.cfm

    You will need to add a motor drive and experiment, I am not sure if it will be possible to reach focus with a DSLR in prime focus. Do your research!! Since I have not used the scope myself, I can only go by reviews from others, like this one:

    Comments about Celestron AstroMaster 130 EQ Reflector Telescope:

    “I consider myself a serious amateur astronomer and I live in the Big Easy where light pollution is a detrimental factor for perfect viewing. Nevertheless I totally enjoyed my first experiences with the Astro Master 130 and on the first night out it took a little getting used to the telescope. On the 2nd night I fared better. I’m glad I did my homework and research on this telescope before ordering. Do yourself a favor and never order anything you haven’t research and reviewed, especially telescopes. I ordered the TELRAD FINDER and a set of Celestron eyepieces along with the scope initially because of the bad reviews about the attached star finder and eyepieces that come with the scope. The star finder scope that comes with the telescope is no good. It’s garbage and I took it off and mounted my TELRAD finder and it works like a baby. Forget about it!!! Get one for your scope and I will guaranty that you won’t regret it. You can’t go wrong with the TELRAD. It’s money well spent for a must have accessory. The eyepiece set is not the best but does the job of providing pleasurable viewing. Wish it had fine focusing but can’t complain too much about it at this price. The tripod is a bit shaky but if you set it up on a hard surface you won’t have any problems. Polar alignment was a piece of cake, made all the adjustments, etc. With a half moon out it looked great. I could make out Jupiter’s bands and moons. Also checked out the Orion Nebula and it looked awesome. The Pleiades blew me away. I could faintly make out the clouds of gas surrounding the stars. Nice!!! Can’t wait for a moonless night. Overall it’s great telescope and it will be with me for a long time. I’m very happy with my purchase and my initial experience with the Astro Master 130 is very satisfying.”

    That is the opinion of only one person, I would try to find an experienced amateur astronomer in Chile and get as much guidance as possible. Maybe there is even an astronomy club you can join?

    Good luck!!

    Best,

    Martin

  6. Chris Philbrick

    Wow – great article, Martin. There is so much out there about AP that it’s hard for a beginner to really understand that you don’t need a $7000 Takahashi tube and an $8000 GEM to get good photos – which two people I have been in correspondence with seem to really believe. Coincidentally, both of these people have plenty of money to throw at their hobby. They gave me some great technical advice, but none of their equipment recommendations were practical for an income of around $45k a year. One guy actually said it’s better to save for a year or two and get the right setup than buy anything inferior – I understand the logic behind this, but there is no way I could justify spending close to $20k all said and done on a hobby at this juncture in my life. What a couple of astronomy snobs 🙂

    I went my own practical route here – I just sold my old Newt and alt/az mount, invested $2300 (which will have me eating VERY cheap for a couple months) in a full setup (very similar to Ray’s Orion setup) and am waiting for it to arrive!

    Anyway, I really appreciate the detailed information in this article. Thank you – you’re doing Huygens proud!

    Cheers and Clear Skies,

    Chris

  7. I got to know of this article when I was corresponding with Martin to buy one of his old EQ mounts. A splendidly written article. It cleared quite a lot of doubts for a newbie astro-photographer like me! I alwys used to wonder how to take the bias frames and now I know!!
    Thanks Martin!!

  8. An informative, helpful article Martin, thank you!

    I’m fascinated with possibilities of the new DSLR HD video functions, have you been able to check them out? I know the resolution is not as good, but the idea of capturing 24 frames in one second sounds good. Then again, maybe just one a second is even better?!?

    I think you’ve just saved me a few thousand!

  9. Tran Boelsterli

    Hi Martin,
    I have Nikon D3100 and Meade 2080 (D=90mm, F=800mm). I took a beautiful picture of the moon with ISO = 200, shutter speed = 1/400, aperture = F11. I’d like to take pictures of Jupiter and Venus now that they’re visible, what settings should I use?
    Thanks so much in advance! Hope to hear from you.
    Tran

  10. Hi Tran,

    Shooting planets is an entirely different ball game – I recommend shooting video and using stacking software to align the different images. If you buy a used Meade LPI imager or a Celestron NexImage solar system imager ($50 – $70 used on Ebay), all the software will be supplied on the CD-ROM that comes with it. I actually have used a Meade 2080 myself, it is a very nice little scope and if you track the planets well, you should easily get 1 minute worth of video, which is plenty to work with.

    The Nikon D3100 shoots video as well, but it is very hard to control the exposure since it is all automatic. Good luck!

  11. Hi Martin,
    I am new to astrophotography but I have been an professional photographer for many years now. I would like to get in to this exciting hobby, since I have always been mesmerized by space, and I am looking to invest around $1,000. What would you recommend for a good setup. I already own a few DSLR cameras.

    Thank you so much for your help.
    -Colin

  12. Hi Colin,

    First of all, thanks for your interest – for $1000 you can definitely get a nice system. The question is what will be your main goal? If it is astrophotography, then a good equatorial mount (like a CG-5 GoTo) in combination with an 80mm apochromatic refractor will hands down be your best choice. Look at the ads on Astromart and Cloudy Nights. I also see a fantastic 120mm EON apo refractor on Ebay but with mount that will end up costing a lot more.

    Now, if your goal is also to do visual observations, then you may want to opt for a Newtonian instead because the larger aperture will show more detail on moon, planets and Deep Sky Objects. The disadvantage is dealing with mirrors instead of lenses and needing to collimate (=align) the mirrors perfectly to get the best results. For just over $500, Telescope.com offers a Celestron Omni XLT 150 Reflector Telescope, on a CG4 mount. Very nice instrument, you would need to add a motor drive and camera adapters as well as a laser collimator (at least another $200) – but it’s a really nice start for not too much money. Since you are a pro photographer, you will have a lot of advantages using high-end DSLR’s and knowing Adobe Photoshop and Lightroom. Still, it will be a very steep learning curve, so be prepared to spend many nights fumbling around in the dark trying to get your polar alignment right and your tracking precise!

    Best regards and Clear Skies,

    Martin

    1. Astrophotography Tonight

      Great tips Martin! I agree, the CG-5 goto and 80mm apo are a good way to go for the money. I started astrophotography with the non-goto version of the CG-5. Would have loved the goto version but it wasn’t available at the time!

      Ray Shore

  13. Dear Martin,
    I am planning on trying to use my Meade 90mm EZ go-to scope for doing astrophotography. Is this suitable at all, or wouls you advise something else.
    Your advice is much appreciated
    regards
    Barrie

    1. Hi Barrie,

      For the moon and possibly the planets (using a simple video rig like the Celestron Neximage) you will be fine with the Meade 90mm GoTo, it is what I used myself for many nice images. However, for Deep Sky objects like the Orion Nebula (M42) or the Andromeda Galaxy (M31) you need a faster scope (F/5 is great) and preferably an equatorial tracking mount – even though you can expose up to 30 sec with your GoTo Alt-Az mount. Hope that helps!

      Martin

  14. Jospeh Ashley

    Martin,

    Excellent primer. I’ve been photographing using a SkyWatcher SynScan AZ goto mount or a 4SE mount (with wedge in the equatorial mode) with various OTAs and a Canon EOS 1000D for several years now. I continue to be very pleased with the capabilities these minimal systems. Here is an example of some of my work: http://www.flickr.com/photos/59237884@N08/

    Joe

  15. Jean-Louis Desplat

    Hi Martin, I enjoyed reading your expose, it’s very clear and down-to-earth. I’ve used Startools to process the DSS output file. Do you have an opinion about its ability to improve sky shots, when compared to PhotoShop? PS seems hard to learn, even the PS Elements? Another question: is it better to leave the DSS output file alone , that is no manipulation whatsoever, and go to a photo enhancement software? Or bring the color out in DSS first? I get quite different results with this last approach. Thanks, Jean-Louis.

    1. Hi Jean-Louis,

      I have not worked with Startools myself but I agree Photoshop is a bit intimidating at first. However, it has a huge range of possibilities. Since I imagine Startools was developed specifically for astrophotography, it is probably pretty cool software. I personally let DSS do its work and leave all my enhancement for afterwards in Photoshop. There may be some DSS experts who can advise you on custom settings but I normally choose for the default settings. The few times I tried to play with it, it did not render any better end results and I found it difficult to control. Nothing beats intelligent experimentation, so if you are up for it, just play around and see what you end up getting! Best regards, Martin.

  16. Jean-Louis Desplat

    Thanks Martin, that was fast. I took the liberty of lifting from this website the whole section dealing with the processing of M42 to turn it in Word doc. I hope it’s allright with you. As for Photoshop I’m certainly not going to spend the amount they want. But my question now is: Would you get the same fantastic result if you only used Photoshop Elements? I would certainly hope it’s easier to use. Regards, Jean-Louis.

    1. Yes, you can keep the Word doc handy on your desktop, no prob. Photoshop Elements works great, you don’t need CS5. In terms of difficulty, it is about the same – just less bells and whistles. Good luck!

  17. Thankyou for your article,I had been told that my equipment was sub-standard but I know know that I have everything I need.
    I am very fortunate in living near a clifftop with a huge span of clear very dark skies right down to sea level.The best things in life are free and thanks to your guidance Astrophotography is almost one of them.
    Many Thanks.

  18. Steve Arnott

    Hi Martin,

    Thanks so much for your very informative article. I think you talked me into the Celestron Powerseeker 80, which costs much less than what I thought I was going to have to pay to dip my toes in the water.

    Just a question: I’m not sure I understand the significance of higher ISO’s in this context. I mean, when your lens is wide open and your shutter is open for more than a second, what does it mean to “use ISO 3200”, rather than 1600 or 800? The image sensors in your camera don’t get any more sensitive when you change your ISO setting, so…

    In the world of “normal”, sub-one-second photography, raising the ISO changes the combination of aperture and shutter speed that your camera will select at a given light level. So higher ISO’s allow you to use faster shutter speeds and/or smaller apertures, with the trade-off being higher noise levels. But once you’re in “I need more than one second to collect the light I need” mode, I don’t think ISO’s are any longer meaningful. Whaddya think?

    Thanks again!

    1. Hi Steve,

      Somehow, my earlier response to your question did not come through. Glad you are picking up this amazing hobby! The Powerseeker 80 is a very nice telescope and you can take some great pictures of the moon and planets with it. It has a long focal length – for shooting nebulas and galaxies (Deep Sky Objects) I recommend getting a faster scope.

      For $100 or so you can get an 80mm short tube (f/5) and with a bit of extra hardware it can be mounted to you Powerseeker EQ mount. It will be a good start and give you training in using Deep Sky Stacker and processing in Photoshop.

      As far as the higher ISO goes, yes – even at longer exposures a higher ISO setting will make a real difference. Especially if you are confined to a simple mount that does not allow precise tracking, the best thing to do is choose a high ISO setting like 1600 or even 3200 and expose for 20 or 30 seconds. I do see your point, and possibly by adjusting the exposure slider if you shoot in RAW mode it would end up very similar with a lower setting. My experience though is that a higher ISO setting will yield better results if you need to keep your exposures relatively short.

      Hope that helps!

      Martin

  19. This is one super article. I will be soon re-reading, taking a print of it 🙂
    I just bought an Astronomer 114EQ and awaiting delivery. Already own a D5000 and a remote, will first learn setting up telescope and then invest into T ring/adapter. Will be bugging you then if fail 🙂

  20. Excellent article! I have been a bit daunted by the sophisticated and expensive astrophotography gear for sale but it is very encouraging to see your results using simple equipment. I am looking forward to using this info to take some deep sky images in the near future. Thank you!

  21. Simon Wilcock

    Hi

    Great article. I have just purchased a Celestron Nexstar 8SE with the Celestron Lens kit and I already have a Nikon D5100 DLSR for which I have purchased some software so I can use it on LiveView on my PC. When I first mentioned to a couple of people about using the Nion, they were a little concered as they used Canon and had a concern that the Nikon was a bit fiddly to get to work.

    I am also unsure if I can just use straight off when attached on my scope or need some sort of shutter control. I have also seen some comments about needed to control the mirror to reduce vibration?

    I have a few books on the way to help me learn about this as I do want to be able to take some great shots like the Orion Nebula if possible.

    The main issue I have is I have had the scope for 2 weeks now and every single night has been clouded, something no doubt I will have to get used to!

    Simon

  22. This article was amazingly helpful and quelled my anxieties! I’m trying to get my fiance a gift and I don’t know much about astronomy or astrophotography for that matter but he’s a photographer with a nikon d600 who’s very excited about dabbling in Astrophotography. As an incentive I wanted to get him a telescope and a t-ring but I don’t really want to spend more than $200. Is this pretty unfeasible?

    Carol

    1. Hi Carol,

      I love the Nikon D600, I am planning to get one myself! For astrophotography, that will be a wonderful camera but $200 will not get you a good telescope PLUS the mount. I looked for you on Ebay and the very least expensive usable telescope plus mount is this one for $250:
      http://www.ebay.com/itm/Meade-ETX-80AT-TC-GOTO-Telescope-Kit-Autostar-Computer-Control-Tripod-80mm-NEW-/360751895092?pt=US_Telescopes&hash=item53fe7d1234 (you can copy and paste the link if it does not work directly).
      Eventually, you fiance will want a small apochromatic refractor (or a fast Newtonian) with an equatorial tracking mount, but that will be closer to $1000. With this little telescope on Ebay he can definitely get started like I did with my simple set-up in the article.

      Best,

      Martin

      1. I will have to let you know how this all turns out. Thank you so much for weighing in as well as the tips – much obliged!

        Carol

  23. I own a Nikon Fieldscope 82mm Ed, a spotting scope. I’ve got a Nikon 7000, and the Nikon adapter, I think FSA-1. this gives me 1500mm telephoto with F13. I
    s there an equatorial mount available that would work with the set up? I’ve used the spotting scope for birdwatching exclusively. But my spouse is interested in trying to take photos of deep space or at least semi deep space. Let me know if you think this is feasible with this equipment. Thanks for taking the time to educate us!

    Bob

    1. Hi Robert,

      For Deep Sky photography you will need a much faster scope than F/13. Best is between f/4 and f/7, otherwise the exposures end up being too long. You can pick up a used CG-5 with GoTo for under $400, that’s a great starter mount. Get a fast little ED refractor for another $300 (look on Astromart) and you are good to go!

      Best,

      Martin

  24. Hi Martin,

    I have just found your tutorial and it was a perfect insight for me as a newcomer to photographing the sky at night, thank you for taking the time to write it.

    I was given a Panasonic Lumix FZ47 as a present last year and one night put it on a tripod and took some shots of the moon, they came out pretty well with some nice craters showing. Now I am keen to take more photos of the sky at night but unsure what camera to purchase on my limited budget. Seeing some of your images using a basic set up has encouraged me further, I would love to photograph Orion and capture the detail of the Nebula for example. My issues is that 99% of the time I am very happy with a bridge camera and as such am reluctant make the move to a DSLR. I have been looking at the Lumix FZ200 which has a 25 – 600mm focal range at f2.8 and much improved noise control I am wondering what sort of results I might expect. I appreciate it has a very small sensor (CMOS) but otherwise seems a very capable camera for a daily shooter with some extended capability.

    I would be interested in your views of what results I may be able to achieve compared to a entry level DSLR like the Nikon D3200.

    Thanks again.

    1. Hi Mike,

      The only way to know if a camera will be good for Deep Sky astrophotography is to try! I’d be very interested to see what you can do with the Lumix FZ200. That zoom range is just amazing and at f/2.8 you don’t even need very long exposures. I would try in the 200 to 300mm range, make sure to get proper polar alignment and stack 10 or 20 one minute exposures under dark skies. Since the camera is fairly light, you can use a simple EQ tracking mount. Good luck, keep me posted!

      Best,

      Martin

      1. Hi Martin,

        Thanks for your reply. I went ahead and purchased the FZ200, it’s a lovely camera. I initially tried it on a cheap tripod, it was fine for Lunar shots but not much else.

        I have now purchased the IOptron Skytracker V2 and a Manfrotto 055XPROB tripod and have run into my next issue, dew and frost. I have been contemplating heat bands but this is difficult with a retracting lens barrel. My current thoughts are to fit the the telephoto adapter tube and put the heat band on that. Not sure what else I can do apart from wait for warmer weather.

        Regards,

        Mike.

  25. Chris Maxwell

    Hi Martin

    Found your website this morning and it was a refreshing experience! Glad to read one doesn’t need $50,000 to photograph objects in space, (there are as many snobs in astronomy as there are in photography). I finally live in an area where I can actually use a telescope in the backyard. After many years of doing photography and using many versions of Photoshop I’m ready for astrophotography. After much research my scope of choice is the Celestron Omni XLT 150 (the budget is $600.00). I’ll be using the Olympus O-MD E-M5 micro 4/3 camera in prime focus as well as piggyback for photos.

    1. Hi Chris,

      Knowing Photoshop is a great advantage, since processing is half of the work. The other half is precise tracking and good polar alignment so your stars look pinpoint sharp. I have seen amazing shots taken with the XLT 150 (the Newtonian, right?) – it’s a good idea to use a coma-corrector as well, will make a real difference in quality. And that little Olympus works very well, I’d be curious to see your results!

      Best,

      Martin

      1. Chris Maxwell

        Hi Martin

        I’ve since come upon a good deal from a friend of a friend. The new setup is a CG-5 goto mount with an Orion 203mm f/4.9 scope for $750 (After a lot of thought I felt that this setup was better and well worth the extra money). My Olympus focuses on the 203 without any problems in prime focus. I was considering selling the 203 for an Orion 8 inch f/3.9 Astrograph that has a focal length of 800mm instead of 1000mm making it a little shorter. The Astrograph also has many nice upgrades especially the focuser which would be a $170 upgrade for the 203. Do you think though the 203 is better balanced for observation and astrophotography then the Astrograph because of it’s longer focal length?

        Thanks in advance
        Chris

          1. Chris Maxwell

            Hi Martin

            Thanks for the heads up on the scope!

            I bought it seeing as it has the upgrades the 203mm F/4.9 doesn’t have and the price was right and I already sold the 203. An 80mm ED refractor is next on my list to complete my setup. There is a utility that is very useful The New Astronomy Press CCD Calculator. It allows one to enter the scope information as well as the camera information then it calculates the fov. Or it can just show the scopes fov. Very handy.

            Chris

  26. Hi Chris,

    The only way to know for sure is to test them both. My guess is that the 203 will be a little easier to work with, because at f/3.9 the collimation is really critical. For visual, I’d go with the 203, but if your main focus is AP then the astrograph may well be worth the extra money. A good focuser is also really nice, and it may be less weight because of the shorter build. Try it out!
    I also recommend getting a small ED refractor for $300 or so, you will be surprised at the quality of the images. Of course, the large Newtonian will visually be much better but harder to photograph with because of the longer focal length. It requires very precise tracking. Hope that helps!

    Martin

    1. Hi Martin,
      I have an atlas eqg with an 8″sct f10 and shoot at prime focus with a 6.3 focal reducer. I use a modded t3i with astronomik filter to capture more reds in nebulas. I’m shooting at approximately 1250 focal length and find that the field of view is limited. I like the aperture value for visual but mainly image now. I use eqmod and cdc software with an phd ascom pulse guiding system so After precise polar alignment I do get very round stars and like to expose for 3 to 4 minutes. I would like to take a wider field image but think I will have to change my scope to an apo refractor with shorter focal length or something along those lines. My next challenge is galaxies and living in LA with light pollution is quite a challenge in itself. Any suggestions?
      Thanks Jim

      1. Hi Jim,

        Sounds to me like you are well on your way!! What you are doing is not easy, because of the long focal length of the system. The Atlas is a fantastic mount and with precise polar alignment you can achieve great results. For galaxies, like M81 and M82 or small nebulas like the Horsehead, your set-up is really great, I’d love to see some of your images. Now is the time to shoot the Horsehead, as well as M42. If you buy a small ED refractor (like an Orion or William Optics 80mm) you will be blown away by the sharpness and relative ease of shooting wider fields, good for M31 or the Rosette. I recommend using a reducer/field flattener and definitely shoot from a dark site, like Sandstone Trailhead above Malibu (http://cleardarksky.com/c/SdnSThCAkey.html?1). It’s worth the drive!

        Best,

        Martin

  27. Hello Martin.

    I’m new into astrophotography and i was wondering what kind of accesories i need. I have a refractor telescope (sky-watcher BK707AZ2) and my camera is a panasonic FZ200.

    Thank you very much for your help!!!

    David

    1. Hi David,

      You have a very simple scope with good optics that will allow you to take nice photos of the moon. The FZ200 is a great camera that you can use for Deep Sky photography (without a telescope) if you get a tracking mount. I am not sure if the lens comes off so it could be hard to attach it to your telescope; maybe there is a special adapter but I honestly don’t know.
      Here is a link to an Orion adapter that will certainly be a step in the right direction:
      http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=201033035341

      Good luck!

      Martin

  28. Richard Thomas

    Hi Martin

    I appreciate the very helpful information you have shared. I am new to AP And would like to know if some of my photography equipment would be useful for deep sky photography. I have a canon 5d with a 300 mm f/2.8 L series lens. I have seen some comments indicating that these lenses might not be well suited for deep sky stuff. I am in the process of buying an Orion Atlas EQ-G mount – tripod. I also have a very old celestron 5 inch case grain. The celestron is about 35 years old and may not be up to the same quality as their latest cassegrains. It has been stored in the attic for about 25 years. Any comments you might have on the capabilities of this equipment would be appreciated.

    Richard

    1. Hi Richard,

      The Canon 5D with a 300mm f/2.8 L lens will be GREAT for deep sky photography! Especially using the Atlas EQ-G mount, which is really a fantastic and very solid mount. Of course, it will be a steep learning curve to get your polar alignment precise and get your focus perfect (I think the 5D has live view, so it will actually not be that hard) and get used to doing long exposure series under the stars. Processing is an art in itself, several great articles on this site about it. As far as the 5″ SCT goes, it’s probably fine for the moon and planets – I’d simply test it. Not so great for AP since you need a fast system. I’d stop down the 300mm lens half a stop or even a full stop to improve overall sharpness. Start with an easy target like M42 (the Orion Nebula) and do 20 or 30 unguided exposures of 30 sec to 1 minute at a dark site. If you use a light pollution filter (highly recommended for less than perfectly dark sites) you can go longer, maybe 2 minutes. Stack them in Deep Sky Stacker and use my article to get a start with processing in Photoshop. You will probably be blown away by the results.
      At one point, you may consider modifying your camera for H-alpha, it will make a huge difference for objects like the Veil Nebula, the Rosette Nebula and the Horsehead Nebula in Orion (which will show very small, but at a good dark site with enough exposure it can be breathtaking). Brent Oliver (http://hyperdslr-mods.blogspot.com/) will do a fantastic job – or you can by a previously modded T2i or T3i especially for that purpose.
      Clear skies!
      Martin

  29. vaibhav narain

    hello sir
    , i own a celestron powerseeker 60 az and a olympus point & shoot camera . can u please suggest me some way by which i can use it for astrophotography. the camera does not have a infinite focusing. or manual exposure setting.
    thanks

  30. Hi Vaibhav,
    With the very simple equipment you own, it will be difficult to do any serious astrophotography. I recommend trying first on the moon: just hold the camera behind the eyepiece and focus as best as you can. Most likely, you will be able to get some nice shots showing the craters. Good luck!
    Martin

    1. vaibhav narain

      sir
      I have shot many pics of moon, Jupiter with 4 moons and plaeides cluster.
      sir can you please give me your e-mail so I can contact you.
      thank you very much.

  31. vaibhav narain

    hello sir,
    I didn’t had any specific questions but I just wanted to show some of my captured pics. and wanted to get some suggestion on improvements. I made a tube like structure to attach my camera to the eyepiece (sort of a T – ring) but the tube attached the cam to eyepiece.it greatly helped to focus and reduce vibration.
    thanks.

    1. vaibhav narain

      hello sir
      can you please tell me ISO values for some most common objects. sir , is it better to keep white balance at auto or any specific setting.
      thanks

  32. For the moon, I usually choose ISO 500 for half moon, ISO 200 for full moon, ISO 800 for crescent. Depends of course on F-stop as well, lots of info on this in my article. Most Deep Sky objects I shoot at ISO 1600. I recommend reading my article as well as many of the other great tutorials on this site.

    Best,

    Martin

  33. Motorizing an Alt-Az mount is only possible if it is designed for that purpose – usually the answer is no. To my knowledge there is no stacking software available for Android, but I am no expert there since I don’t use an Android myself.

  34. Hello sir,
    1. My compliments for your exquisitely clear website.
    2. I have a Canon Rebel T5i, my wife has Canon Rebel T3i. We have passion for photography and i would like to start astrophotography.
    We have zoom lenses (70-250 and 18-250). According to your article i could shoot interesting photos with our zooms, we will try and let you know.
    3. Anyway, to improve the quality of our photos, i would like to buy a telescope spending not more than 450 bucks. I hope i will make a good choice.
    4. Specific question? Yes. Could i contact you for suggestions about the telescope i will buy?
    Thank you for your answer and renovated compliments for the article!
    Ciao

  35. Hi Antonio,

    Thank you for your nice comments. When it comes to buying a telescope, the most important thing if you want to take photographs is the mount. I recommend a used equatorial mount, preferably with GoTo or at least with motor drive. The Celestron CG-5 Advanced GT is probably your best bet:

    http://www.celestron.com/astronomy/celestron-cg-5-computerized-mount.html

    As a very inexpensive but great starter scope (good enough for photographing the moon and planets) I recommend this one:

    http://www.opticsplanet.com/celestron-powerseeker-80eq-telescope-package-21048-op-80-eq-telescope-21048-with-moto.html

    If you are handy, you can probably find a good way to mount your camera with zoom lens either directly on the mount or piggyback on the scope if it’s not too heavy. The price is amazing. Good luck!

    Best,

    Martin

    1. AstroPhotography Tonight

      Good feedback Martin. That CG-5 Advanced GT is a good low cost mount for astrophotography. Very popular.

  36. Sorry – I’m a near-newbie, and really struggling to understand how all the bits fit together. You say:
    “first, you place your eyepiece in the camera adapter (best to start with a 20 or 25 mm eyepiece since it gives you a wider field) and then attach it to the camera and the telescope”
    What do you mean by ‘camera adapter’?
    I’ve used a T-mount and camera ring to attach the camera directly to the telescope – I presume this is what you mean by ‘prime focus’ – or with a Barlow, but I can’t seem to find any way of including an eyepiece in the setup.

  37. I have astromaster 130 EQ.I tried astrophotograpgy using canon 60d and 2xbarlow-adapter.Moon image lacks details.I came to knwo it is due to the limitations of the focusser.

    I removed the barlow part ,but the moon appears to be blured.

    Any solution for this?

    Regards

    Jijo

  38. Tony litchfield

    Hi Martin
    A wealth of information and so much to take in.
    I have just started astrophotography.Just un modified DSLR (possibly thinking if getting a second hand canon 60da)and tripod.So milky way shots so far in a semi dark sight on the uk coast.I would like to photograph deep sky objects too.
    Choices are to buy a £600 fast telephoto lens and image what I can from a static tripod,then eventually purchase an eq mount.I was wondering how difficult it is to find deep sky images with a telephoto lens ?.
    If I purchased a goto eq mount without a telescope,can you complete 2 or 3 star alignment easily ?
    2nd choice is an eq goto mount with telescope and dslr,and later purchase a telephoto lens and piggyback.then I will have the choice of imaging through telescope and telephoto lens.
    Lots if questions I’m sorry but it’s a challenging subject to get into.
    I have never used a telescope let alone a new mount so was wondering if it is a long learning curve.

    1. Hi Tony,
      For £600, you can easily get a great used equatorial GoTo mount, possibly with money to spare for a small ED telescope. I love my little William Optics ZenithStar 66 ED, which is a small but very well corrected refractor. In the USA, they sell for less than $300 used and they are fantastic for wide field astrophotography. The mount is really the most important part if you plan to track the stars. Polar alignment needs to be precise, and that’s another challenge. One of the great things about this hobby is that the learning curve never stops, no matter how advanced you are. Alignment on the stars for GoTo can initially be an exercise in frustration (especially with the cheaper mounts) but once you have it right, it works amazingly well. So much to learn and so much to enjoy – go for it!

      Clear skies,

      Martin

  39. Hey Jijo,

    Make sure to use the live view option when you focus. Even with a cheap focuser, once the moon is in focus you can get sharp images. With a Newtonian like the 130EQ, the mirrors also need to be aligned (collimated) for best results. But if it looks really sharp visually, you’ll be able to get sharp photos as well. Avoid any shake and just keep trying!!

    Best,

    Martin

  40. Thanks Martin, more compliments from me too on your great article. Thanks to you I stopped listening to a couple of local astro nuts who had me convinced to buy $6000+ worth of equipment. I am now hunting for second hand cheap refractors from astronomy forums. Can’t wait!
    BTW that poster Tony mentioned buying a used Canon Da camera (ie Astronomy model). There’s heaps of info and videos on the web showing how to uninstall the normal IR filter and replace it with the astronomy Ha filter. It seems a pretty cheap way to get an astronomy camera … but Martin, does that work as well as a proper Da model?

  41. Hi Howie,

    You can find a used Canon 60Da for under a $1000. You can also get a modified EOS (like the T2i or the T3i) for $500 or so. I personally use a Baader modified 450D which cost me even less ($350 on Cloudy Nights).
    If you do the modification yourself you’ll save more, but it’s a job I prefer leaving to experts like Brent Oliver (HyperCams & Mods, he is a great guy).
    Will a modified EOS work as well for AP as the factory made 60Da? Absolutely. The main advantage of the 60Da is that you can use it both for regular and astro photography without any custom white balance (after the modification, normal photographs will look pinkish). But since I have other cameras I use for my regular photography I never felt the need to buy a Da. I used a borrowed 20Da at one point and I much prefer my modified 450D. However, the 60Da is a wonderful camera and I have seen great results with it.

    Clear skies!!

    Martin

  42. Hi Martin,
    Thank for all the info on this website, it really helped me to understand all the basic concept of astrophotography. I’m new to this and I’m currently using a nikon d600, can you please tell me what will I need to start shooting the moon, planets and maybe Galaxy? Please tell me what adaptor I need for my camera. My budget is around 200-300. By reading other users comments, I’m thinking of the Celestron 130 EQ or 80 EQ with motor mount. What do you think?

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