I'd like more info about infrared flooding illuminators

general discussion
#1

Hello again forum! Here is what I have:
I’d like to know more about infrared flooding illuminators and also which ones I should probably buy.
I’m using as a base article Flong’s “A Brief Note on Infrared Filters: 87 vs 87C” http://www.flong.com/blog/2010/a-brief-note-on-infrared-filters-87-vs-87c/
I have both 87 and 87c filters and I’ve searched for infrared flooding lamps and/or illuminators but the cheapest (and most common) led ones don’t mention IR wavelength. I’ve also encountered many illuminators that have a spotlight effect.

What I’d like to know:
1-Which infrared illuminators have you used?
2-Which ones would you recommend?
3-Are very cheap security illuminators worth it?
4-How could one verify if they are worth it or not?
5-How can I determine how much infrared light I should use?
6-Is the wavelength really that important as long as it is infrared?
7-How do you counteract the spotlight effect?
8-Do spotlight diffusers work to counteract the spotlight effect in infrared?

Also, I welcome any comments, experiences and anecdotes. =D

Infrared tracking using Flea3 PointGrey camera
#2

1-Which infrared illuminators have you used?

http://www.supercircuits.com/Infrared-Illuminators/IR14
http://www.supercircuits.com/Infrared-Illuminators/IR20
And regular light bulbs or PAR Can ( stage lights ), with 2xCongo Blue and 2xPure Red Lee filters ( cheap IR filter )
( see this link: http://amasci.com/amateur/irgoggl.html )
Also custom made IR LED light in a TL tube housing ( something like this but with ir LEDs http://www.alibaba.com/product-gs/507594058/rgb-led-tl-tube-light.html )

2-Which ones would you recommend?

If its for longterm then LED ( and the more expensive the better ).
The first two in the list above I’ve seen the LEDs burn out after a year.
Also the IR14 panels suffer plastic fatigue and crack, so don’t use them for ceiling mounting.

If its for a show / short term, using stage lights or even regular lights with a IR filter works well and puts out a lot of light.

3-Are very cheap security illuminators worth it?

They are not terrible, but so far my experience is you get what you pay for.

5-How can I determine how much infrared light I should use?

Well one way is to imagine how much light you would need to illuminate the room to be very bright ( if the filters were not in or if the IR leds were regular leds), then multiply the amount needed by 4 or 5. It can be a little hard to estimate and a lot depends on what you are tying to do with the IR camera.

6-Is the wavelength really that important as long as it is infrared?

Well yes. The camera doesn’t see all of the IR spectrum, so you want to best match the wavelength that the camera sees ( near IR ) and what the filter allows through. Most IR lights though are designed for this range.

7-How do you counteract the spotlight effect?
8-Do spotlight diffusers work to counteract the spotlight effect in infrared?

More lights, bounce the light of a surface ( wall , ceiling etc )
Never tried a diffuser, but what works for regular lights would prob work in infrared too.

Also, I welcome any comments, experiences and anecdotes. =D

#3

theo is basically a master of infrared for interaction, so read his post very carefully :slight_smile:

the only difference, in my experience, is that i haven’t seen the IR14 panels have the fatigue/crack problem. i’ve left them on continuously for about 3 months at a 45 degree angle in an air conditioned room that probably varied from 60-80F (16-27C) and didn’t see any cracks or wear.

depending on how complex your setup is, it might be worth it to talk to someone who has professional photography experience. studio photographers have a slew of special equipment (diffusers, bounces…) for getting lighting just right. they might have some ideas about how to get the scene illuminated in the way you want.

#4

Just for the record - here is the issue we experienced.
This happened to 3-4 of the lights.
This was after one year, hanging straight down from the ceiling.
There might have been a small vibration in the ceiling that could be causing stress on that connection.
Just good to know if you don’t want them to be falling on people’s heads. A good rule is to have a safety cable or zip tie as a failsafe for anything ceiling mounted.

We also used them in a more standard setup where they were mounted on the floor, to flood a wall. Now 2 years later, some strips of LEDs on the panels are dead.

For the cost though they are pretty good, I wouldn’t hesitate to use them for short term installs.
One other thing to know about both of those IR lights from super circuits is they are light activated. You need to cut the photo resistor from them to have them be always on.

#5

WHOA!
I’ll read this thread many many times! Thank you both for the info and I’ll be back later. =D

#6

I think you guys have answered all of my questions. Thanks!
=D

#7

Hi Theo, I’m working on a project that’s in a similar situation. I want to put hacked PS3 cameras on the ceiling to detect the movement of people below. Since the space I can use currently is much larger than I expected, I may need to use several cameras and maybe two projectors. I’m now pretty confused. I’m wondering how many cameras you used? If more than one, how did you joint cameras’ views together? And how did you seamlessly joint two projectors’ views into one especially considering that it’s a head-to-head set up rather than side by side? Thank you so much!

#8

Just to add to this as it took a while to find, here are some pricy but very nice IR lights

http://www.santec-video.com/eng/produkte/scheinwerfer/infrarotscheinwerfer/ir_13dn

They have excellent coverage and are smooth with no hot spot even at 2m. There are a wide range of models with different angles. they are pretty industrial and have very solid cases for mounting.