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View Full Version : How to take Infra-red shots with 20D



Blue Star
04-06-2005, 06:55 PM
How can I do infra-red photography with my 20D ? Is it something I so while image editing ? or I have to put some sort of filter on my lens ? FYI my lens has 62mm thread.

gabester
04-06-2005, 10:42 PM
How can I do infra-red photography with my 20D ? Is it something I so while image editing ? or I have to put some sort of filter on my lens ? FYI my lens has 62mm thread.

dSLRs have a filter in front of the sensor to reduce "leakage" of infrared radiation into the visible spectrum. You can remove this filter physically, although it appears it's not for the faint of heart. Here are tutorials for Canon (http://ghonis2.ho8.com/rebelmodnew.html) and Nikon (http://www.astrosurf.org/buil/d70/ircut.htm).

TheObiJuan
04-06-2005, 10:52 PM
doing so would render the camera useless for normal shooting without using an IR filter on each lens.

gabester
04-07-2005, 08:36 AM
doing so would render the camera useless for normal shooting without using an IR filter on each lens.

There is some compensation if you use custom white balance, but I've heard that you may need to use both that and a filter to get back to what you had before. Personally, I wouldn't do it since it would void my warranty and I've no infrared needs. Besides, I can't even put back my daughter's Canon Powershot S110 that I took apart to try to fix the E18 error. LOL

TheObiJuan
04-07-2005, 08:43 AM
the sony f series have IR capabilities.

ReF
04-10-2005, 10:35 AM
i've done tons of shots Infrared shots with the digital rebel 300d without any of the physical modifications mentioned above. i'm not sure if the 20d has a different filter though. i use a Hoya R72 infrared filter that simply attaches to the front threads of the lens. for my fisheye lens i use a Kodak wratten B89 (equivalent to the Hoya r72) gelatin filter that attaches to the back of certain lenses. very long shutter speeds need to be used though - i use 30sec exposures at ISO 400 f/16 on bright sunny days. i should also mention that there was a list of lenses that worked well for IR photography and others that caused "hot spots." i happen to own only the ones on the "good" list so i don't know how pictures turn out with those on the "bad" list(not sure about the fisheye though).

Blue Star
04-10-2005, 07:23 PM
Thanks Ref.
I will try to get this filter.

D70FAN
04-10-2005, 07:24 PM
i've done tons of shots Infrared shots with the digital rebel 300d without any of the physical modifications mentioned above. i'm not sure if the 20d has a different filter though. i use a Hoya R72 infrared filter that simply attaches to the front threads of the lens. for my fisheye lens i use a Kodak wratten B89 (equivalent to the Hoya r72) gelatin filter that attaches to the back of certain lenses. very long shutter speeds need to be used though - i use 30sec exposures at ISO 400 f/16 on bright sunny days. i should also mention that there was a list of lenses that worked well for IR photography and others that caused "hot spots." i happen to own only the ones on the "good" list so i don't know how pictures turn out with those on the "bad" list(not sure about the fisheye though).

Very cool. Could you post a few of those?

gabester
04-12-2005, 03:32 AM
i've done tons of shots Infrared shots with the digital rebel 300d without any of the physical modifications mentioned above. i'm not sure if the 20d has a different filter though. i use a Hoya R72 infrared filter that simply attaches to the front threads of the lens. for my fisheye lens i use a Kodak wratten B89 (equivalent to the Hoya r72) gelatin filter that attaches to the back of certain lenses. very long shutter speeds need to be used though - i use 30sec exposures at ISO 400 f/16 on bright sunny days. i should also mention that there was a list of lenses that worked well for IR photography and others that caused "hot spots." i happen to own only the ones on the "good" list so i don't know how pictures turn out with those on the "bad" list(not sure about the fisheye though).

The reason you need such long exposures is that now you have two filters in place - the original IR filter built into the camera, as well as the external "infrared" filter over the lens. I think the latter is just a low-pass filter that attenuates the shorter visible wavelengths (remember wavelength and frequency have a reciprocal relationship). So you're removing basically most of the radiation before it gets to the sensor; hence the very long shutter speeds. If you want to dedicate a camera mostly to IR photography, and want shorter shutter speeds, you have to remove the built-in IR filter, which to me is a scary enterprise. :D

ReF
04-13-2005, 03:24 PM
Very cool. Could you post a few of those?

okay, i'll try and do that sometime "soon." (soon to me is sometimes a long time to others ;) )

i've been pretty discouraged about posting pics in the gallery because it seems that shots can come out pretty awful looking depending on the settings of the computer/monitor that is being used to view them.

gabester: i know about the built-in IR blocking filter and why i need such long shutter speeds, but i don't have the money for a dedicated IR d-slr with the filter removed (i think canon will do this for their d-slrs for a charge but i haven't looked into it), nor do i like the idea of carring around an additional body and switching cameras and lenses all the time. but your info would be good for those that are new to IR photography.

ReF
04-14-2005, 04:07 PM
Very cool. Could you post a few of those?


George, i posted a few IR shots in the gallery like you asked.
the thread is called "Infrared." creative title huh? ;)