On 15 Jan 2004 at 12:08, Roger Wong wrote: > At 08:31 PM 1/14/2004, Willem-Jan Markerink wrote: > >Overlooked the rather interesting exposure spec's on > >http://www.irdigital.net/ : 200ASA, 1/[EMAIL PROTECTED] > >(hmm....that's conflicting, with 200ASA SunnySixteen says 1/[EMAIL PROTECTED], > > or almost 1/[EMAIL PROTECTED] cq a true 1/[EMAIL PROTECTED]). ... Which means that > >regardless of whether D30 or D60 *can* record IR, there is still a > >very strong IR-block filter inside... > > I don't think so. In fact, it means the opposite! The camera > modification inserts a strong IR-only filter inside that blocks out > normal (non-IR) light. Let's assume that IR makes up 25% of the > wavelength spectrum that the chip is sensitive to. Block the non-IR > light means 75% less light. This is equivalent to putting a 2-stop ND > filter in front of the lens. Thus, to record only IR light, you must > use longer exposure times.
Sorry, I meant that the D10 samples given elsewhere (2s shutterspeed) indicate that a strong IR-block filter is used in EOS digicam's in general.... Btw, for those interested in the UV-aspect as well, check some brand/model comparisons (as well as analog vs digicam) on this site: http://www.naturfotograf.com Sad to see that almost all Nikon bodies do lots better in both UV and IR.... While the SunnySixteen-conflict is simply actual exposure-index vs 'film-speed'. > And, like Peter K. says, Sunny16 is more of a guideline rather than a > rule, especially the farther you move from the equator. So, that's > also another factor, albeit minor. But not 2.5 stops. Even on Velvia I get away with SunnySixteen, both in north-European summer and Alpine winter. -- 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 ***********************************************************
