IR Photography with DSLR

Joined: 05 Jun 2006 Posts: 245 Location: Northern MA

I know this is the B/W forum, but I couldn't really find a section where I think this question better belongs, except maybe the General Photography.

I'm interested in trying my hand at IR photography, but I guess I'm a bit confused about it.

I have a Maxxum 5D, which, based on many of the sites I've visited, should be able to handle IR photography.

In addition to my camera, tripod, and remote release, (skills aside) do I only need a filter at this point? Supposedly, the Hoya R-72 is the filter that I'd need for IR with the Maxxum.

Any help would be appreciated. :)

Joined: 25 Dec 2005 Posts: 1106 Location: London, Ontario

Yep, the filter is all you need. Be prepared to loss a lot of light (not sure how much) but Ive heard that it can be hard to even compose your shot because the filter blocks so much visible light. On the bright side (no punn intended) the light loss doesnt seem to effect the AF. I would guess that the Infrared light that is let through the filter is enough for the AF.

I could be wrong on some or all of this being that I have never used IR filters but this is what Ive gotten from talking to a few people that have. Im sure some of our rez IR shooters can correct me later

Posted: Sat Aug 12, 2006 1:50 pm

Finalstand is mostly right. The filter is all you need. But, the filter doesn't just block most visible light, it blocks virtually ALL visible light. You have to compose your shot before you put the filter on. AF does still function with the filter, at least on my Canon 10D, but I usually focus before putting on the filter (especially since I usually manually focus).

Your exposure times are going to be way longer than you're used to. 15s @ f/8, ISO 200 isn't unreasonable. I've had to go as high as 30 seconds. Lots of light is a good thing, so shooting in the afternoon is a good time.

The images are going to be very very red, until you post process them. For post processing, you can either convert to b&w, or you can do a false colour IR by reversing the red and blue channels in the channel mixer.

Here is one of my IR shots. The first is the b&w version, the 2nd is false colour.

Good luck, and have fun! Let me know if you have any other questions.

Posted: Mon Aug 28, 2006 2:45 pm

I used to have a 5D, and with a Hoya R72 you have to give yourself an additional 14 stops to compensate for the filter. The results can be quite nice, but remember to pack your tripod.

Joined: 31 Jul 2005 Posts: 131 Location: Boulder, Colorado

Ok...this is ventureing further off the topic....but has anyone seen any "prosumer" digital camcorders that offer this same sort of image capture? Better yet, anyone know of a video forum similar to these?

Posted: Tue Feb 13, 2007 12:51 am

Fisheye, thats way of topic. Could you start a new thread please.

Posted: Tue Feb 13, 2007 2:49 am

regarding the filters: doesnt anyone know the difference between an RM72 and an RM90. I read that the 90 filters out up to 900 nm of light and the 72 filters out 720 wat the heck is the difference?

Joined: 27 Apr 2005 Posts: 577 Location: Rochester, NY

Some transmittance data for your viewing pleasure:

http://www.hoyaoptics.com/pdf/R70.pdf
http://www.hoyaoptics.com/pdf/R72.pdf
http://www.hoyaoptics.com/pdf/RM90.pdf

A comparison chart (Scroll down a bit):

http://www.hoyaoptics.com/color_filter/ir_transmitting.htm

I hope that helps.

Mike

Posted: Tue Feb 13, 2007 4:11 am

Sorry, it looks like i resurrected a pretty old thread. Still, some good gen still being added to it.

Posted: Tue Feb 13, 2007 4:02 pm

so really the higher number for the filter the more IR light it will pick up? or is the the more visible light it will block? How does blocking visible light (or adding more IR light) effect the film? Perhaps just exaggerates the effects of the white and blacks?

Posted: Tue Jul 24, 2007 5:07 pm

The higher the number the more non-IR light is filtered out by the filter.

Joined: 31 Jul 2005 Posts: 131 Location: Boulder, Colorado

Yeah, the upper limit of the IR that can be captured is listed for the films....I know some do not capture any IR over 720, making the dark filter pointless. The old Kodak stuff went to the high 800's or 900's. The mian visual difference I see is less "white" in the leaves and such. Someone posted a shot of a house not long ago in the B&W forum that was IR, but looked like a Tri-X shot with a deep red Filter...all the leaves were in the typical grey-black tonal range.