Sunday, July 2, 2017

Some early results with a "video eyepiece" and my very old Nikon film camera

 
Now that the Fourth of July holiday weekend is underway, and I now have a polar alignment scope and dew heater controller, it's time to begin mastering this optical and mechanical marvel known as a Celestron EdgeHD Schmidt-Cassegrain and an AVX mount. I have been practicing getting good polar and GOTO alignments, and learning how to use the All Star Polar Alignment feature in the hand controller. I have been able to get a star to stay still for half an hour, and just tonight I got the polar alignment scope roughly calibrated, then a decent polar alignment with is right afterwards.

At the same time, I was trying the telescope out with my inexpensive video eyepiece on the Moon, Jupiter and Saturn. I'm also starting to learn the intricacies of a nifty free program called Registax6. It extracts frames from the AVI video files, aligns them, and stacks them to form a still image that can be sharpened enormously BEFORE you import it into a photo editing program such as Photoshop. The results I have achieved so far include the work below.

The photo of Saturn was made with a 2.8X Barlow lens, but all of the lunar photos were taken at prime focus. In other words, I simply used the telescope as a giant telephoto lens. I'm sure I could indeed photograph VERY distant subjects during the day time with this telescope, but turbulence would blur the photos.
 
 

 
 
 
 I achieved much more success so far than I was ever able to with my old Meade model 628 6-inch Newtonian and equatorial mount and my camera. I wasted whole rolls of film because finding objects and focusing the camera were VERY hard, I got the exposure time wrong, the polar alignment was WAY OFF or some other glitch scuttled my photos. It was wonderful to see the result as soon as I finished recording the video on my lap top. However, these pictures also show I will have to get a much better camera and among other things, a flip mirror and filter wheel. The limitations are obvious, especially when I was trying to image Saturn. It's faint and quite hard for the camera to record it well. I would also like to be able to record video of deep sky objects or take still images at some point.
 
However, I will be using my film camera, which is a Nikon F-3HP that I had for over 25 years. It's was a top of the line camera when it was introduced back in 1980, and still is today as far as 35mm film cameras are concerned. I have a T adapter that make connecting my camera to the telescope simple and allows me to use it as a 2,000 mm F/10 telephoto lens. That is how the last picture was taken, using Fujicolor 200 color print film. I found focusing the camera difficult, and to address that I got a Bathitnov mask, but it appears a clear focusing screen is needed, or a flip mirror. The photo wasn't as sharp as it should have been, but aggressive use of un-sharp masking and careful scanning of the film made a presentable picture possible. The photo is of the entire frame, not cropped.
 
I am used to the simplicity and quick set up of Dobsonians, and I won't be retiring them any time soon. They beat the EdgeHD SCT handily in terms of light gathering power and resolution. My 15-inch Dob easily shows objects that simply cannot be seen through any 8-inch telescope at the same site. However, the SCT has very good image quality. Combine that with a mounting that is stable and has excellent pointing accuracy once you align it correctly, this telescope is a very good choice for an all around telescope. For someone who wants a GOTO telescope that can be used for imaging at a later date, in a package that will fit in any car and is easy to set up, an 8-inch Celestron EdgeHD SCT is a telescope you should consider. If I was starting out in astronomy today, I would have wanted this telescope for my first telescope, even though I would have had a lot to learn along the way.

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