5D MkIII infrared performance
I remember reading somewhere that the 5D3 had a relatively wimpy AA filter, so I wondered if it also passed more IR.
Just got around to trying this. Stuck the new 5D3 on a tripod, and pointed it out the window in idiot mode. Correct exposure:
f5.0, 1/500, ISO 100
Then dropped in an infrared filter, switched over to full manual, and played with the exposure until I got the histogram looking about the same as the unfiltered shot. Result:
f2.8, 1', ISO 8000
So, I figure we've got 6.3 stops difference on the ISO, 1.7 on the aperture, and a whopping 9 stops difference on the shutter speed. Add 'em up and you've got a 17 stop penalty. I remember testing my old 1D2, and it was more like 13 stops. I just did the 5D2, and it was also about 17.
So, no, an unmodified 5D3 is definitely not a good infrared shooter. And that's the last IR shot I expect to shoot with one until my modified camera comes from Spencer's--I expect that one to be an outstanding IR camera!