I'm Going To Area 51!!!, page 4

i just put this contraption together in preparation for my trip. 90x zoom scope attached to a high resolution night vision cam/videocam... i'm pretty excited to see what we catch!



[edit on 4-3-2009 by hiii_98]

reply to post by hiii_98

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You will find that magnification means less light. For a given aperture, if you get twice the focal length, you get 1/4th the light. This is why most night vision doesn't have much magnification associated with it. You should be able to do daytime shots.

I was in the range on 3/9. It was snowing, and at ground leve, not the hills.

reply to post by hiii_98

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You can't fight physics. More magnification means less light. You only choice would be to haul a large reflector up the peak, i.e. get back some aperture.

Night vision is a buzzword. Some night vision is merely a CCD illuminated with IR. This is hardly useful becaues you can't throw IR very far. [I have a tank IR filter than I put in front of a spotlight, so I have an IR beam that is useful to make 200ft.] Real night vision is starlight illumination, that is, no IR source used.

You would actually do better with a still camera and a long exposure. If you shoot video, you can stack frames with imagej (a free program). Stacking frames is a way to reduce the digital noise.

One alternative is to get a CCD B&W video camera and use your telescope in prime focus. [Easy with a refractor scope, sometimes problematic with a reflector, depending on the back focus. Take at look at the Supercircuits website.
supercircuit camera

I've used this camera with a telescope (i.e. focal plane), using a camcorder to record the video. I've also used the camera with motion picture c-mount lenses. This camera and a large aperture c-mount lens is pretty close to the crappy hardware store night vision.

I used a less sensitive video camera (P23C I think) in a macro mode to focus on the screen of some soviet era NV I bought. It is gen2, but substatially better than the crap they pass as NV these days. I did this video with it:
a51 night vision pano
The macro is done with a 13mm lens and a spacer between the lens and CCD camera to get it in macro mode. All this takes a lot of optical hacking.

Now one thing I haven't done, but I suppose I should try is to pull the lens off the nightvision at put it at the back of the telescope. I suppose this requires a bit more explanation. If you look hard enough, you can find soviet era (or perhaps even modern) night vision that uses a screw mount lens (Pentax screw mount, not Leica). The soviets saw no need to invent a new camera mount, so they copied the screw mount. Now in theory, you can use the night vision as a focal plane for the telescope. You amplified the light from the scope, then use the CCD macro to video the back of the night vision tube.

It will be far cheaper to experiment with the low light CCD camera at the back of the telescope. Better yet, use a DSLR and long integration time.

The night vision that has screw mount lenses is made by Cyclops. Here is a link:
cyclops NV

I'm using a Rostov Cyclop 11b2. The construction is similar to what is shown on the Kiev website. Everything is metal. This is military gear. Mine is very old, so it has some dark spots on the screen. The good thing is few people know this type of gear exists (well, unless they read my posts), so you might find one on ebay. That is, the seller might not even realize the lens can be removed.

Occasionally gen3 US NV tubes show up on ebay. Since you are using a telescope, you have all the optics you need, well assuming you can construct a macro to focus on the NV screen output. The problem is mechanical support. This is really serious hacking.

reply to post by hiii_98

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I forgot to mention ITT Nighvision is C-mount. I ran into someone around the range that scammed ITT to sell him one at dealer cost since he had a resale license. A damn good deal. Something like $1800 for a gen3 system. Gen 3 is leaps above gen 2. Most of the hardware store (Famous Trails) is gen 0, not even as good as the low light CCD I suggested in my other post.

If you get the supercircuit CCD, Ebay has this lens:
**COSMICAR 1:1.9 / 50mm C-MOUNT LENS FOR BOLEX**
This should work as a NV scope.

reply to post by lernmore

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agreed, what soldier in a desert would deny such a beverage? anyways be safe, good judgement works well!

reply to post by hiii_98

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Does the lens come off the night vision? If not, you are doing eyepiece projection to get the image to the night vision focal plane. [Not so good.] Does the ocular of the night vision gear come off. If not, this will require another eyepiece projection. This is also known as a relay lens. I'm not predicting good results. [Eyepiece projection for increased magnification for a telescope does work, and can be cheaper than getting a good barlow. You need to use simple orthoscopic eyepieces. I've done this with University Optics orthos. Fancy lens that offer a wider view are actually worse for projection.]

The best scheme is to have the light from the telescope fall on the NV focal plane. Then you do a macro video or photograph of the back of the NV intensifier.

I haven't found a decent alt/az for photographic use. I got the biggest gear head from Bogen and put it on a relatively cheap carbon fiber tripod. [Ebay for the gear head. The Velbon Carmagne is about $200, which is a good price for carbon fiber.] I made my own telescope mount. I got an off the shelf counterbalance from Orion (telescope.com) to balance the setup. You want the front glass of the telescope to be as close to the pivot point of the gear head. This reduces the image movement due to wind. I haven't found an alt/az that does this, which is why I built my own. Mount alt/az set up the center of balance of the scope assembly (scope and attachments) over the pivot. That negates the need for the counterbalance, but it is not very good for photography.

I still say your best bet is to get the Supercircuit low light camera if you want video. Because the sensor is very small, you get an effective (those false) increase in magnification because it is only looking at a very small part of the image. This is assume you use the CCD with the scope in prime focus. I haven no idea what kind of spotting scope you are using. If the eyepiece can't be removed, this gets more complicated.

The Takahashi FS78 was dropped from the product line, but you can probably find it used. The cheapest thing they now make is the Sky 90, which is a bit much for shooting from Tikaboo (though a great scope). The Orion ED80 (or whatever they call it now) is actually pretty good for something made in China. You might be able to find the older version that was made by Vixen.

For viewing through 26 miles, you don't want too much aperture. You would need to read the paper on "poor seeing". It is generally accepted that under poor seeing conditions, you want a refractor with 3 to 4 inches of aperture. A reflector scope really should be used for such work. The only reason to use a reflector is to get large aperture for astronomy. But with astronomy, you only have about 2.5 miles of atmosphere to deal with.

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