IR-filters where to buy??


#1

Hi ppl!!

Does any body knows where to buy Ir-filters…Im looking and looking but nothing…

suggestions are more than welcome!!

F/ :smiley:


#2

you don’t need to buy an ir-filter, just take a strip of good old black film (that stuff that they used to make pictures with). i don’t know if negative or positive film is better, i just used slide film.

best
joerg


#3

This is something that I have ben trying to solve. I have used a couple of things.

First just an IR photography filter. this works well, but not blocking all light in a room. It does a great job with blocking the projection image tho.

I have also tried an astronomy IR filter it was a bit $$ and did nothing special. It was said to block all light below 900nm. I have found it almost impossible to block all light but IR, there is IR in all light hmm.


#4

we typically use kodak wratten 87c to block projection, for co-located camera and projection works… I find this works fairly well and blocks projection 100% and fluorescent light too (not completely, but mostly). it definitely wont block sunlight or incandescent light, but often times, I’ve seen IR used to control the amount of light (ie, flooding a wall with IR) relative to environmental conditions…

– zach


#5

I’ve tried with theater gel filter: rosco congo blue: 5 or 6 layers will do for filtering the camera, for what i’ve tried it works better than photo film. You can also use it to filter an incandescent light an get a cheap yet powerfull infrared light (be careful it can get burnt). A 60cm x 40cm (aprox) layer cost 4 or 5€.

From the filter curves, it also seems that combining a rosco congo blue layer with a lee light red layer will do, although i haven’t tried.

You can find where to buy from their webs:
http://www.rosco.com/
http://www.leefilters.com/


#6

a few minutes ago i found this on the makezine blog:
http://blog.makezine.com/archive/2007/0-…–pict.html


#7

I just got a Kodak Wratten 87b filter in the mail.

It filters out a lot more visible light than several layers of exposed 35mm film.

although its more expensive (price went up to 68.50 from 49.95 this month)

http://www.bhphotovideo.com/bnh/control-…-bmit+Query

graphs of the kodak wratten IR (87) filter range:

http://www.x-raycameras.com/kodak-wratten-87-range.htm


#8

if you are going to try to use film then processed, unexposed colour slide film works better than any other type of film. 2 layers should be enough to block all visible light while still letting loads of IR through. And is considerably cheaper than a real 87b filter. depending on the size of your lens you may also want to go up to 120 roll film (60mm wide). Be sure to ask the lab to *not* cut the film after processing, and that yes, you do actually know what you are want. :slight_smile: they will look at you funny if you hand them a brand new roll of film for processing.

(and wear white gloves, fingerprints suck)

S.


#9

I use Kodak Wratten filters and have found them a godsend at that last minute in a pinch, especially when using DLP projectors which start from a full white light and therefore need more blocking.

I often use cheaper R-72 filters though on other projects (or with LCD projectors) because that allows more light through and works fine (always accept “good enough”). It depends on what you’re working with. But I always keep that Wratten in my bag, just in case.

Since I’m in Europe, I use this place, because it’s got all sorts of crazy lighting filters and devices that, if you’re adventerous enough, you can do some amazing things with:

http://www.edmundoptics.com/

Apparently they have a US outlet. There are other distributors/competitors selling similar instruments, but I’ve found Edmund Optics pretty good for all around filters I need, with accurate charts. I also buy Micro lenses from them, because they allow me to work in tight corners with cheap cameras (anything from garage sale Logitechs up to Unbrains) and not have to worry about removing the IR-Cut filters.

When you use Visible-Cut filters, you also have to think about infra-red lighting. I have yet to find the ideal lighting solution on this front, although there is a new product that looks appealing (although somewhat expensive):

http://www.extremecctv.com/BlackDiamond.php


#10

As arturo says, the congo blue and a red filter do a hell of a job.
I’ve been using this for a long time, is cheap and very efficient.
The recipe: one or two layers of congo blue, plus one of deep red. I found the trick here: http://amasci.com/amateur/irgoggl.html

I’ve been using this since the first experiment with the “khronos projector”, BOTH to generate IR light (at first I used an incandescent lamp with this filter), and then to detect the IR light (remember to strip the IR-CUT filter from the camera!).


#11

I have produced 2 projects now using visible cut filters from an outfit called LDP:
http://maxmax.com/aXNiteFilters.htm

They are somewhat pricey but work very well. I have tried the exposed film trick as well as a couple of photo filters and have the best results with these LDP items.

I find the 715nm pass to be good for indoor work where the only IR sources are incandescent lamps. For any situation where sunlight is affecting the space you will need a higher wavelength blockage. Obviously the more dynamic your environment is the more stingy you have to be on the visible cut.

best of luck.
ds


#12

I have produced 2 projects now using visible cut filters from an outfit called LDP:
http://maxmax.com/aXNiteFilters.htm

They are somewhat pricey but work very well. I have tried the exposed film trick as well as a couple of photo filters and have the best results with these LDP items.

I find the 715nm pass to be good for indoor work where the only IR sources are incandescent lamps. For any situation where sunlight is affecting the space you will need a higher wavelength blockage. Obviously the more dynamic your environment is the more stingy you have to be on the visible cut.

best of luck.
ds


#13

Yes, I can also recommend the xNite filters. I used them because we had a budget, but I’ve also used film and it works great too!


#14

I bought a sheet of this stuff from Edmund Optics:

http://www.edmundoptics.com/onlinecatal-…-uctID=1918

It is significantly cheaper than the glass filters sold for cameras, and can be easily customized to your desired size and form.

The material is a thin plastic. It can be cut using the score-and-break method or a laser cutter if you have access to one. A dremel would probably work also, but its a bit harder to get the edges clean.


#15

Hi, i’ve been using 3 gel filters, a red, a green and a blue one. and it works really well.
We’re using it to cover a camera lens to block visible light to enter and also in front of 2 light projectors to make some nice IR projectors, and so far it works really well on both. :slight_smile:


#16

I have used custom cut camera filters from this company

midopt.com

with great results