On 1 Nov 2004 at 23:41, Jay D. Washington wrote: > Several days ago I read a thread about Infrared shooting with Canon > Digital SLRs, but I did not have time to respond. Anyway, there is a > reason that shooting with P&S digitals with infrared filters look > different than shooting with Canon DSLRs. The difference has to do > with the filtering and tolerances of the digital recording chip. CCD > base cameras (read P&S Canons and other manufacturers DSLRs) make > better infrared digitals than CMOS based cameras. Something about the > tiny glass filters required in front of the recording CCD chip that > lets about the same amount of infrared sensitivity as infrared film. > CMOS based Canons have different filters and tolerances and don't > respond to the infrared light, but instead over a long exposure record > the visible light that is getting through the filter (That's why with > a 87 filter, you will get a picture with a long enough exposure, but > it won't look like a traditional B&W infrared photo). I'm sure there > is someone out there who can explain this in a more scientific way, > but the bottom line is CMOS camera make poor digital infrared cameras; > however, CCD cameras work like a charm. > > Cheers, JD > > BTW, I didn't know this until I bought an expensive 77mm 87 infrared > filter and found my 10D photos looking like dull low contrast > non-infrared B&W photos. I was disappointed because I had gotten such > good results with a smaller 87 filter on my G-1. I then researched > info on the web about digital infrared capable cameras.
Actually, it's a bit more subtle/complex than this....even within EOS DSLR's there are differences: EOS-1D (I&II) is CCD, 1Ds (I&II) is CMOS. But the difference is not (just?) in the IR-sensitivity, but the odd mechanical detail that the IR-block filter on the 1D can be removed, while the one on the 1Ds can not. And removed it can also be on most lower EOS DSLR's....the only commercial source for this conversion that I know of is http://www.irdigital.net. And yes, I did try to pass this message onto Canon R&D through my contact at the last PhotoKina, but for me personally it's already 2 (second hand....;)) models too late....as a wide-angle/fisheye shooter, I probably won't buy anything else than a 1Ds. (though it's also interesting to note that my contact mentioned quite casually (as if it was common knowledge) the fact that CMOS was a bit softer in contrast than CCD)) Also feel free to join the Infrared Photography Mailinglist, to discuss this topic in a more general (brand) context: http://www.a1.nl/phomepag/markerink/ir_list.htm Another important advantage of removing this IR-block filter (and replacing it with a neutral anti-alias filter!) is that the effective speed increases enormously, almost to the level of Kodak HIE (1-2 stops less IIRC). Just as interesting: on some (most?) pro-backs (medium/large format), the anti-alias filter is optional....latest incarnation even mentions this in the brochure, the Mamiya RD DSLR (& RD-back). I even talked to one of the engineers at the Kina (damn does that cost a lot of effort, I had to fight my way through at least 3 levels of hierarchy, waving with business-cards of each lower level....:)) (oh well, walking around in cut-off jeans has it's downsides too I guess....;)) (but hey, at least they remember you, just as when being an obnoxious customer in a restaurant....:)) -- Bye, Willem-Jan Markerink The desire to understand is sometimes far less intelligent than the inability to understand <[EMAIL PROTECTED]> [note: 'a-one' & 'en-el'!] * **** ******* *********************************************************** * For list instructions, including unsubscribe, see: * http://www.a1.nl/phomepag/markerink/eos_list.htm ***********************************************************
