Perfecting your telescope technique


Message posted by Gary Sellani on September 19, 2000 at 00:32:56 EST:

As those on this list know, the distance from Tikaboo to groom is 26 miles, so any decent photos will have to be done with a telescope. If you go to the www.desertscecrets.com website, the basic technique to take photos through all that haze is to use B&W film and a red filter. I noticed that Walmart sells a Kodak B&W film that you can develop in a C41 process, which is your basic print film. [Yes, you are doing B&W in color.] Thus you can take it to a one hour lab and talk them into developing it. It takes some arm twisting as the results when printing the film can be pretty weird. If you have access to a film scanner, then prints are not a problem. I've read on the net that Walgreens can handle printing this B&W film, but I didn't try them. Rather I scanned the negatives.

http://www.lazygranch.com/images/moffet.jpg

For those familiar with the SF Bay Area, the distance from Rocky Ridge in San Ramon to Moffet Field in Mountain View is 26 miles, and there is terrible haze over the bay, which makes it a good test target. This URL has a composite photo where the top is done with a 400mm lens, while the bottom is done though a Meade ETX90 with red filter, projected through a 26mm eyepiece. The shot takes 6 seconds, so a tripod and low wind are needed.

As you can see, the results are not bad. If anything, I need less magnification, which is something I am working on. From comparing the Terraserver Area 51 photos to the Freedom Ridge photos on this site, it looks like each photo spans about 800ft. [This is parallel to the film plane, not taking into account the angle of the photo.] I'm at about twice the magnification, but the photos really aren't that sharp, so less magnification would be better since you would get a brighter image. In fact, a losing a factor of two in magnification would make the image 4 times brighter.


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