You may have heard about a new and exciting product coming on the market from Celestron. It's called the EdgeHD aplanatic Schmidt telescope. According to Celestron, this scope is "designed to produce aberration-free images across a wide visual and photographic field of view". In fact, the EdgeHD performance is being compared to that of an astrograph when it comes to "coma-free" optics . Astro-imagers cannot wait to see the first reviews come in for this new scope. Here is the official video preview of the EdgeHD:
Other Notable Features of the EdgeHD
Another interesting feature is the EdgeHD's mirror locks that hold the main mirror in place. These locks should minimize image shift (caused by mirror flop) when rotating the tube. Image shift is a common problem with traditional SCT's. It normally occurs during focusing (with the manual focus knob) or as the telescope optical tube crosses the meridian. Although Celestron has been able to keep much of the mirror shift to a minimum (e.g., their focusing mechanism is supported by two pre-loaded ball-bearings), they have incorporated mirror locks in the design of the EdgeHD scope. This is a very welcome improvement for astrophotographers.
Also, the EdgeHD optical tube has built-in cooling vents to help bring the optics to thermal equilibrium with the outdoor temperatures. Heat rising off of the primary mirror will cause distortions (like the mirage effect) and result in an unsteady image. This is a common problem that astro-imagers deal with if they are using closed tube systems. Waiting for the warm air to release from the tube takes away from precious imaging time. It will be interesting to see how effective these vents are for releasing warm air.
The EdgeHD SCT is exciting news for astrophotographers. The discussions will be numerous as these new scopes make their way into field. We can't wait to see some of the results from the astro-imaging community! Feel free to leave comments regarding the EdgeHD in our comments section at the bottom of this post.
The EdgeHD will be available on Celestron's new CGEM mount or heavier CGE Pro mount.