Low light level image intensifier DSP or circuit needed

Does anyone know of a way to get a brighter image from a low light level source using a small camera. I have tried using several "low light level" pencil cameras, including some expensive professional ones but they always seem to be slightly darker than a modern DV camera which is a bit too large for my use due to confined spaces. Getting a camera with a lux sensitivity level does not seem to be sufficient. I have not found any where I can reduce the shutter time below

50Hz to get more light (other than USB outputs but I need video output). I just need to brighten up the image an F-stop or two. Some cameras seem to be very bright but they seem to have internal compensation which has no effect when the whole image goes darker. Thanks

Especially if you take out the IR block filter. Sony does this for their 'nightshot' feature. It royally messes up color...

Otherwise try a brighter lens (lower F-number).

Thomas

I didn't think it was at all possible to actually use a standard Sony, and see through material. That would be interesting just for checking if someone had a weapon or not, under their clothing, whether metal, or a plastic knife, etc. What modifications would be required?

Thanks--- R>

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Any Sony camera with Nightshot takes the normal IR filter out when that mode is engaged. But you also need to add a visible light -- infrared photography (B&H and others carry these) - filter, in order to see *only* the infrared.

Because some people used the things for voyeuristic photography, all recent (about 6 years) camcorders disable the manual controls when nightshot is enabled. It locks the iris open, max gain, which is what you want for true nightvision. But it badly overexposes any daylight shots (indoors may still be OK).

There may be a firmware hack to disable this, which would make the thing more useful for daylight IR shooting. Otherwise, a ND filter might be enough to make the exposure useful in bright light.

Tinted glass is more transparent to IR, and also, IR generates less reflections off the glass. Both combine to allow seeing through windows more easily for surveillance.

It isn't actually Xray, and you won't see through clothes per se. What you do see through is material which is less reflective to IR than visible light. A lot of fabrics are tranluscent to IR (and UV).

Note that the effect applies just fine when used with IR lights at nighttime. Sony Nightshot camcorders have an IR light on them, which is what makes them workable for true "shoot in the dark" photography.

For low light photos, IR lights are one solution which is usually cheap enough to try out, even if you don't have a camcorder/camera with an IR mode like Sony's Nightshot.

There really isn't a true "light intensifier" circuit per se for a CCD. Some cameras allow for increased gain-up, increasing noise (picture graininess), but a post-process "brightness" software filter (or the equivalent in a real time video processor hardware box) will do almost the same thing. It doesn't actually increase detail in most cases. It simply makes the entire picture brighter.

But that can be enough to make a low light picture more usable.

A better alternative, if you can't use lights (even IR lights) to brighten the scene, is using a better low light CCD/camera. Size is an issue -- the small pencil cameras have small CCDs, and that affects the light sensitivity. Bigger CCDs beat smaller ones for low light.

I'd go with IR lights (even small ones are a big help) and a night vision camera which sees well in IR.

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On a sunny day (Sun, 16 Jan 2005 08:22:04 -0600) it happened Jeffery S. Jones wrote in :

The small (cheap) cameras use CMOS sensors, not CCD. CMOS sensors are not that good at low level (noisy, differences between pixels).