Re: photographs of area 51

Message posted by gary on December 10, 2002 at 20:36:51 PST:

I've done photographs over the same distance as tikaboo to groom lake (but locally) and found that extended red film (AKA near IR) doesn't make any difference. In fact, the red filter that you typically use with such film is more useful than the extended red film itself. Note that extended red film only takes you out to about 0.85 microns, which really isn't much of a heat signature. Real IR would go down to about 10 microns.

If you read up on IR film, it tends to be very unpredictable, so I'm not sure I'd want to use it for a shot from Tikaboo except on an experimental basis. Another problem with IR is that unless you use flurite lenses or a reflector telescope with no other accessories, the visual focal plane will not be the same as the IR focal plane. Thatis, if you focus visually, the IR image will not be in focus.

What I have done to take better long distance photographs is to use an orange filter (with BW film), which helps improve the contrast without as much light loss as the red filter. Then I push the film a stop which increases the contrast. When you shoot through 26 miles of atmosphere, you lose contrast due to the haze. Pushing the film increases the contrast, but it also increases the grain. However, if you try to increase the contrast of photo using photoshop or corel, you also increase the grain. It's better to push the film instead of electronic processing because the grain increase is not that significant for one stop (a factor of two), and you get less blur due to camera shake with the effective higher speed. That is, the original image (prior to photoshop) is of higher quality.

In Reply to: photographs of area 51 posted by darkhorse on December 10, 2002 at 13:24:05 PST:


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