vibe

Sun has set and tonight it seems to be working much better. Right at sunset the motors whirled, picture banked for a second and then it was b&W. Earlier I discovered I had white-balance turned off - turning it on seems to make a difference. Old streetlight is definitely producing IR, the second camera is pointing towards it and objects directly under it are all glowy and there's enough light as if it's daytime (but b&w). The second camera is also using a different brand varifocal lens. It makes me wonder if the first lens does indeed have some kind of mild anti-IR filter coating. I got these off ebay used and they are randomly selected from a batch, I am going to try to get more next week to experiment with. Picture from both cameras are much, much more useful than my old m12 cmos board cameras.

Yeah part of the bad image is that it's a capture off the quad view and not full view, and it's off a TV capture card, so double the noise. Looks much better in person and recording playback. The first one (board camera) is definitely IR because it's ghostly white during the day with super-muted colors. It can also see things at night like a person walking across a completely dark background. I'll see what happens tonight now that I have two of the same to compare pointing towards different pools of streetlight. Like I said before, my uneducated guess is there is different IR sensitivity on the CCD sensor where the streetlight IR spillover just isn't in the CCD's range. The CMOS was more sensitive to whatever wavelength that was. The only other possibility is that either the lens has an anti-IR coating (which I highly doubt).

I can definitely hear the ICR kick in, it's a short little motor whirl sound as it goes from color to b&w (or back). The m12 lenses were f2.0 but I think these CS ones are F1.6 (I think). I'll try pointing a remote at the cameras tonight or this weekend and see it lights up on the IR (I also have a illuminator but it's a pain to hookup right now).

I've been reading up a bit and it's plausible that the cmos sensor was picking up some IR light at a different wavelength from the streetlights (very old school, I am sure they have some unintentional IR in there) Where the CCD only picks up IR much closer to visible light. For now it's the only explanation I have. I've put up a second camera with a different lens that gets far more of the streetlight so I'll see what happens tonight. I'll say one thing, 480TVL with these big (made in japan) lenses gives me a much better picture than the old 380-420TVL and M12 lenses (even with a high quality M12 lens). Can't wait until megapixel IP cameras are more affordable, all digital over ethernet is definitely the way to go, analog almost seems silly these days but it sure is cheap.

Learning more every week now, thanks for all the help. Here's my newest question: Even if a lens isn't specifically built for IR, it should still allow a sensor to capture some IR right? As long as there isn't a coating to block IR? Here's why I ask - I am trying out my first real box CCD camera - a low end, generic TDN camera. Awesome picture during the day. At night it definitely goes into B&W mode and definitely gives a better quality picture than my old board cmos. But the old board cmos definitely picked up IR at night. People stood out, the white lines in the parking lot really reflected - foliage definitely reflected as white. The box camera does not seem to see the IR. Right now I am using a lens that was probably meant for indoor use but it does not seem to have any coatings that would block IR. Compare the two screen caps (sorry they are from the quad view so the res is low but you get the idea). This lighter one is a cmos sensor 380-420 lines, see all the IR? This darker one is the TDN with 480 lines. But no apparent IR? Happy to learn whatever insight you can give me - does the TDN box just not have an IR sensor - or is it the lens? Shouldn't all sensors pickup some IR? Should I risk disassembling it to look for any additional IR filter even though it has a mechanial IR-cut filter?

Oh wow nice. Where can I buy those? I just bought a couple of box cameras just to get TDN ability, oh well.

TDN is probably under a price revolution this year. The mechanical switch to move the IR-cut filter is down to $10 now http://www.dhgate.com/ir-cut-filter/r-ff8080812b51ebc8012b52d4943a0f0c.html#1

I am trying to find something reasonable price-wise with mechanical switch filter. Need to check opinions on the Digimerge DCD110043B it's a $50 true day/night apparently: http://www.digimerge.com/images/file/Specification%20Sheet%20for%20the%20DCD110043B.pdf but maybe I should start a new thread for that

No it's definitely M12 (and not varifocal) I would definitely not try to remove the filter (especially since I only have one lens with one and it's great quality). How thin are those glass filters though, because the lens already has to get quite close to focus - I guess I can buy an extender.

Oh awesome, I'll make my own true day/night, just the price sucks: http://www.electronics123.com/s.nl/it.A/id.2901/.f http://www.electronics123.com/s.nl/it.A/id.3122/.f I'm curious how the focus can be kept since the filter in theory should slightly change the focus but I might give that a try.

I believe IR-cut can also be a coating. The bottom of the one lens I have that is actually IR-cut has a red coating. Though it may very well be a carefully mounted piece of glass on the bottom or even a plastic disc, I dunno. I'm up to a half dozen different lenses I've bought and none of them have IR-cut. I guess they just don't do it anymore. I found this collection which carefully lists if they have IR-cut or not, but their prices are twice ebay plus shipping, so it will be a last resort: http://www.electronics123.com/s.nl?sc=16&category=&search=lens%20filter

I've given up and am just ordering different lenses from different suppliers to see what I end up with. Fortunately they are cheap enough to experiment. I looked carefully at the one I got a few years ago and the quality is really nice - when I look at the new ones I got this week, it's typical made-in-china style where they slowly start to cut corners on the quality to increase profit. Metal housing is now plastic, glass is plastic, etc. One looks like it once had a filter coating and someone must have scratched it off to make it full spectrum, which is crazy.

So is there such a thing as a clear gel IR-blocking filter? That you get in sheets and cut down?

Wow those are some really nice board cameras. I bet they cost several times more than what mine did though.

A few years ago I bought a cheap "board" camera but apparently got lucky with a really good lens. The picture and color quality was quite acceptable. So last week I ordered a few more board cameras (different sources to sample) and when they came in, same board but they've all got different lenses with IR filters on them (not IR cut). I really want the daytime colors, at night the area is lit well enough to work at the minimum end of the camera's range without IR. After asking a dozen ebay vendors, they all only have IR filter, only found one in Miami supposedly with IR cut and have a sample coming in to be certain. What's interesting about these cameras from different sources - ALL their IR filtered lenses are DIFFERENT ! They are all 3.6mm but they have different levels of IR filtering, so there are slightly more colors (saturation) in one lens than another. One is horrible and everything is nearly pure black and white during the daytime (hence my other confused thread) but another one is slightly better, you can definitely spot reds and browns, another actually shows blues properly and the grass has a slight green to it, but the whole picture has a hue to it like you are looking through sunglasses (it definitely still has IR because at night the grass is white). Can I somehow make my own filters on the cheap to experiment (something like exposed film, I dunno?) or is this implausible? I think I am also going to try to buy 2.8mm to see even more - but I am sure I will have the same IR problem.