3 posts from February 2008

One of the common problems for sky-waters in the winter is dew forming and crystallizing on the optical surfaces of the telescope. Many combat this by using heaters wrapped around sections of the scope called dew zappers. I do not have one, so once the scope begins to frost, I'm forced to pack it up. Coming very close to the dew point, I decided to squeeze in a few photos of the moon with my D200 through the scope.

There are two major hurdles doing lunar and planetary photography with a D-SLR through a scope: Focusing and combating atmospheric seeing conditions. Compared to a nice, bright eyepiece, looking through a DSLR provides a much dimmer, wider field of view that makes it very difficult to perform fine focusing. There are solutions, either using a computer to control exposures and analyze focus as you take multiple photos adjusting the focus each time or by utilizing a live-view if your camera supports it.

Even if "perfect" focus is achieved, a photo may still appear to be blurry due to atmospheric conditions (heat rising, ect). Looking through a scope during "poor to moderate seeing" is like looking through heat-waves (see this 45 second clip of Jupiter for example). The best lunar and planetary images are done by using webcams that are capable of super-fast frame rates of 100+ frames per second. Software goes through hundreds of photos to find the sharp ones.

Even under decent seeing, I'm still having great difficulty focusing without the aide of a computer, a webcam or live-view. I did get a couple sharp ones and they look amazing when viewed at their full 10MP resolution (something you cannot get with a webcam). This is not cropped and gives you an idea of the field of view I get with the setup.

Finally, here is a candid group shot with me at the scope.

    Unfortunately, sometime within the last few months, I was diagnosed with a very expensive illness that makes for cold, sleepless nights and long periods of time staring at the sky. That's right, the astronomy bug.

    Being a very wide field with so much to learn and so many different things to try, getting into astronomy reminds me very much of the overwhelming, yet exciting feeling I had when venturing into photography.

    So, for the last few clear nights, I've been stargazing through the glory of a big 10" scope (a Meade LX200R). It is a truly amazing piece of hardware: GPS, super smooth slewing and tracking and Ritchey-Chretien optics (same as the Hubble).


    Last night was the first night ever (after only 3 nights of viewing), that I decided to try some down and dirty astro-photography. I say "down and dirty" because true astro-photographers use a complex method of photography involving two cameras, one for guiding the scope through a finder scope, and one for doing the imaging itself. The advanced guys also take advantage of a CCD's linear exposure recording and "stack" multiple images of the same scene for the benefit of better dynamic range and noise performance.

    As I am still learning those techniques, I decided to take a much simpler approach last night. After aligning the scope, I had the scope track the target. Using a T-Adapter, I connected my trusty Nikon D200 SLR to the scope and took a single Raw exposure (repeating until I got a somewhat focused shot). I later processed in Photoshop. These are the results.

Two from last night. Comments Welcome.