Re: Question

Message posted by gary on April 01, 2002 at 20:10:28 PST:

Typically the ones sold at the hardware stores are pretty poor, but the price is right. ;-) [They are Russian gen0.] When I was touring the area with Sedalia Mike and Catman, Catman had a Russian nightvision scope that accepted screw mount optics. I got a similar unit on ebay, though it is gen2 and I think his was gen1. The screw mount lens feature is pretty good because you can either attach the scope to a telescope using a screw mount T-mount, or attach screw mount lenses if you want more magnification.

On the trip with Mike and Catman, we went to the border to snoop on the camo dudes with the nightvision. To be honest, with moonlight, I was able to spot the camo dudes with the LCBs (large Chinese Binoculars). These are 12x60, where the second number indicates the aperture. For night viewing, you want large aperture.

Getting back to night vision, we did manage to spot the camo dudes. However, what was interesting was to point the nightvision over the range (i.e. beyond the border.] We could easily see flashing lights over the range.

Now to make a long story longer, when I made another trip a few months later, I had my own nightvision system. Joerg and I hung out at the gravel one night and did some extensive fiddling with it and came to a fuzzy conclusion:

You can see lights moving in the sky over the range, but by pointing the nighvision toward highway 6 you also saw flashing lights, so we figured out you can see planes for maybe 80 to 100 miles. That is, planes flying in commercial airspace show up as well.

I think it would be pretty difficult to see a plane image outline flying over the range. Without going into the lens math, the brightness is inversely proportional to the square of the magnification. [OK, I had to do some math.] This means to make the image in the view finder twice as large, you get a quarter the amount of light. These nightvision intensifiers do not seem to be very linear with respect to the light falling on them. In fact, if the light is really low, you get a noisy kind of light show, i.e. not a full image. What this really means is that to be able to see something through the nighvision, the magnification can not be very high. Think about spotting a plane over Groom Lake with 10x binoculars say 10 miles away. I doubt you could make out the shape. Now consider that nighvision will be about 3x magnification (at best) with much less resolution. Hence all you will most likely see are flying flashing lights.

I think a more useful technique would be to take long exposure photographs while pointing at the range. You might learn more about flight patterns, which in turn may clue you in as to where to look for planes in the future.

The commercial planes will play follow the leader. The interesting stuff will be renegades.

If you just want plane trails, slide film would probably be better.

In Reply to: Question posted by SAM on April 01, 2002 at 17:05:31 PST:


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