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.

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. 

*
****
*******
***********************************************************
*  For list instructions, including unsubscribe, see:
*    http://www.a1.nl/phomepag/markerink/eos_list.htm
***********************************************************

Reply via email to