IR Filter

[sciguy]

IR Filters continued...

Thanks for the tip Steve. You said this is what you are using? What camera are you going to use too?

The filter I found that I mentioned was only about $7 for a 2" x 2" piece. I wonder how high the quality will be though.

These filters are really good and are characterized for the entire spectrum. They are basically opaque to anything below 810nm. 810nm is 1%, 850nm is 45%, and 920 is 88% all the way up to 2100nm where is starts rolling off again.

I bought two (one for spare). It will be filtering either a standard Sony Low Light (IR sensitive) camcorder or a www.x10.com NightWatch wired video camera. The targeting computer takes a standard RS170 NTSC video signal as input, so I can use any video source that has a phone jack video output on it. I didn't go the webcam direction and wanted to create a totally standalone system.

best regards, Steve

[nick_g_evans]

Thanks for the tip Steve. You said this is what you are using? What camera are you going to use too?

The filter I found that I mentioned was only about $7 for a 2" x 2" piece. I wonder how high the quality will be though.

[sciguy]

IR Filter source

another option that I used was one from http://sro-optics.com/. When you go to the site click a message at the bottom if their left side navigation menus don't show up. Click on Filters and go near the end of the page. They have 2" x 2" Melles Griot filters that are IR longpass and start passing IR at 850 ($22 each). At the LED wavelength, they pass 80-90% if I recall correctly (the spec sheet is at home).

best regards, Steve

[kallahar]

The IR filter I'm using came off ebay, it's a filter intended to be put over the cap of a flashlight so that you can use it with night vision. Cost about $8. You can also remove the internal IR filter off a webcam fairly easily, just a couple of screws.

[nick_g_evans]

I did find a great source yesterday. Edmund Optics has some great IR lowpass filter plastic available that is really cheap. I already ordered some. You can find it at www.edmundoptics.com.

I almost kept this to myself just to keep my competition guessing, but I decided to take the social route instead of the cutthroat method.

[dataworm]

Here some info for those who lack google skill:
http://homepage.ntlworld.com/geoff.johnson2/IR/

It's about the same thing on a Digital photo camera, but it's a little more difficult to disassemble and put back together...

Unfortunally you will never get that result from that kind of hack http://lcamtuf.coredump.cx/tsafe/

[dataworm]

If this is for a digital camera it may not work. Many digital cameras have a filter to not allow IR light in.

If it for a film camera make sure the camera can support IR film. Cameras with little windows for the film info or lots of plastic won't work. Metal is needed to keep out the IR light until exposure. The older the camera, the better.

I use a Hoya RM100 which lets in absolutely NO visible light. It was almost $300 from the source.

Ebay is a good source, but timing is everything. Good luck.

Astcell this might apear as a crime agains Digital Camera , but the trick is to open the Camera and remove the IR Filter, then you remplace the IR Filter by a few layer of exposed film to block normal light and only keep IR.

Been there, done that it's kinda cool to do with a old Digital Camera. It also work on most webcam btw...

Oh and yea astcell before you ask I did't try to do that with my Digital Rebel ;) I ain't that crazy

[LosT]

For IR fun, take a digital camera, and point it at an IR source (like your TV remote)- then push the buttons, while watching in the LCD preview screen- In most digital cameras you will see the IR in the preview screen-

Tune in next time for more stupid forum tricks...

LosT

[astcell]

If this is for a digital camera it may not work. Many digital cameras have a filter to not allow IR light in.

If it for a film camera make sure the camera can support IR film. Cameras with little windows for the film info or lots of plastic won't work. Metal is needed to keep out the IR light until exposure. The older the camera, the better.

I use a Hoya RM100 which lets in absolutely NO visible light. It was almost $300 from the source.

Ebay is a good source, but timing is everything. Good luck.

[nick_g_evans]

Thanks for the tip. I will look that up.

I read somewhere on another forum, useing a exposed color film negitive works well for IR pass filter.
have fun

[mage2]

IR filter

I read somewhere on another forum, useing a exposed color film negitive works well for IR pass filter.
have fun

[theprez98]

Does anybody know of a cheap source for an IR pass filter for a camera. I have found some on ebay, but they cost more than I want to pay for.

In its own strange way, eBay sets the market price for many items. Unless you find something on closeout or some special deal, I doubt you'd find anything cheaper than eBay (at least that has been my experience).

[nick_g_evans]

Does anybody know of a cheap source for an IR pass filter for a camera. I have found some on ebay, but they cost more than I want to pay for.