AstroPhotography Tonight is pleased to present this exclusive interview with professional photographer Martin Cohen of Santa Monica, California. Martin has traveled across the globe to create his special works for numerous photo publications, clients, and photo exhibitions. His website, Martin Cohen Photography is a reflection of his mastery with a camera.
Martin’s talents extend into astrophotography where he applies his skills in imaging and photo processing to night sky subjects such as the Moon, galaxies, and nebulae. Martin’s strengths in astrophotography include imaging with low cost telescope platforms and image processing using Deep Sky Stacker and Photoshop. AstroPhotography Tonight published two articles written by Martin in these areas: Creating Seamless Mosaics in Photoshop and Astrophotography on a Budget. The photo gallery of his work below is a testament of what can be accomplished in astrophotography with affordable telescopes and sophisticated image processing. We appreciate Martin taking the time to share his experience in astrophotography and we look forward to learning more from him. Martin’s interview with AstroPhotography Tonight starts below his image gallery.
Please tell us about yourself. How did you get started in astrophotography?
I have always been fascinated by the moon and the stars, even as a kid. When I was twelve, back in the late sixties in Amsterdam, Holland, a friend of mine got a telescope for his birthday. One night, he showed me the moon. I was awestruck! Within a few months I got my own: a 2” Polarex (Unitron) Alt-Az refractor. I still have it, optically and mechanically it’s wonderful little telescope. In 2009, I got a 90mm Meade GoTo refractor on Ebay for under $100 and started photographing the moon. I was hooked. From there on it evolved into Deep Sky photography and I can easily see myself doing it for many more years. The great thing is you can keep growing. Right now I am in the intermediate stage: when I see the images produced by advanced astrophotographers I know how much more there is to learn.
What equipment did you learn on (i.e., camera, telescope)?
Actually, I took my first photographs of moon and planets with that little 50mm Polarex and a Russian SLR: the inexpensive but quite functional Zenith B. I was sixteen and did my own developing, pushing Tri-X to 1600 and 3200 ASA. Those were the days… I remember going to an astro-camp in Switzerland where I was showing the heavens to Belgian boy scouts, and another youth meeting in Italy where I ruined the secondary of a 16-inch reflector by cleaning it with a bit too much zest, so the silver came off. Precious memories…
Did you have any mentors or someone who inspired you during your early days in astrophotography?
I never had any mentors or teachers but I always learned from reading and experimenting based on what I knew. I had several books on astronomy as a kid and over the past years the Internet has been an unbelievable source of information. So many great photographs, inspiration is everywhere! Also, I found that even the most advanced astrophotographers are usually very generous with their advice and willing to share their knowledge. Cloudy Nights and Astromart have many wonderful members, the CN forums contain tons of information. Astrophotography Tonight is another great website to learn from.
What equipment are you currently using for astrophotography?
I currently image with a simple Skywatcher EQ5 mount with a Synscan controller. The scope I use the most is a William Optics Zenithstar 66 SD because I really like the wider fields. I often borrowed a Canon 20Da from one of my astro-buddies, and a few months ago I got my own modded DSLR, a Canon 1000D. I always use light-pollution filters, the Astronomik clip-ins are really great. My second scope is an Orion 110 ED, which is a nice semi-apo refractor. Lately I have used the more detailed images of my 110 ED in combination with the wide field shots of the Zenithstar 66. And only a couple months ago I could not resist picking up a simple Orion 80 ED for $250 on Astromart. They are amazing performers, especially for the price. The only way to know how a certain telescope works for imaging is to get one and start shooting with it. That’s why I will probably buy and sell quite a few more instruments in the years ahead. But my Zenithstar is a keeper!
What is your favorite imaging subject (planets, moon, nebula, galaxies, etc.)?
I love the moon and the ever changing landscape as the shadows of mountains and crater walls move over its surface… It is also a great challenge to photograph ever finer details. I have yet to get into planetary photography, I tried a few times but was never blown away by the results. I do have an 8” Newtonian that I hardly use and I imagine I could get some decent shots with it in combination with my Celestron NexImage video camera. Still need to try! In terms of Deep Sky photography, my favorite constellation is Orion. Lately, I start almost every imaging session with M42, just to test if everything is working properly. Ironically, my best shot of the Orion Nebula came about this way, just shooting three 90 second subs and two shorter exposures to get the hot center more defined. M42 is a very easy target for imaging, and quite beautiful.
Do you belong to any astronomy related organizations?
I am not a member of any astronomy club, but I do subscribe to Cloudy Nights (free) and Astromart (very inexpensive). I highly recommend these two websites, both for information and for buying equipment.
Do you have any published works such as articles, books, tutorials, videos, etc?
I have published an occasional article back in Holland in the seventies and taught a beginners astronomy workshop in 2011.
There are two of my tutorials on Astrophotography Tonight: one on creating mosaics in Photoshop and the other on astrophotography with inexpensive equipment.
What, in your opinion, is the toughest subject to image?
Wow, there is always an even tougher subject when you get to the next level! I tried the Cone Nebula recently and it did not look like anything. At my current level that one is certainly a challenge – and I am still working on getting the Horsehead Nebula just right, I did a decent widefield with a 180mm telephoto lens two years ago but you need a lot of fotons to make that one pop.
What do you consider to be your best work in astrophotography?
Usually, the best work is the most recent. Some of my moon photographs from 2010 with a 10” Dobsonian (a scope that I sold last year) are still nice, they are all mosaics. I was also happy to get a decent shot of the Veil Nebula last year, not an easy one to image.
Astrophotography has a steep learning curve. What in your opinion is the most difficult part to master?
There are two really difficult parts to astrophotography: the art of perfect guiding and the art of processing. They really go hand in hand as you progress. Getting your polar alignment right, making sure your stars are tiny pinpoints… it’s not easy. Because photography is my profession, the processing part came a lot easier to me since I already knew Photoshop. But even with processing, I have learned a lot over the past two years that I did not know when I started. You have to be a little bit obsessive to get this stuff right.
What recommendations can you provide for those who are interested in entering the field of astrophotography?
For anybody who is starting out, I’d say first learn the night sky, the constellations, where the planets are… get a nice 8” Dobsonian to start with and take some photographs of the moon. That’s relatively easy and you don’t need to track the stars. If you want to do more serious imaging, then be prepared to spend a lot of time and effort – it takes patience and practice. Hands down the best and least expensive imaging scope to start with is the famous Orion 80 ED, which sells for about $300 used. You will need an equatorial mount with a tracking device – I recommend the Celestron CG-5 and the Skywatcher EQ-5. You may want to buy them new for $650 or so, or used for $500, they keep their value quite well. Then you’ll need a modified (“modded”) DSLR – I got my Canon 1000D used for just under $300. Add a sky pollution filter, a T-adapter with a T-ring… and you are pretty much ready to go!