Re: IR in the studio

[Goff Photo <jdgoff@xxxxxxxx>]

At 05:06 PM 4/24/97 +0100, you wrote:
>Hi All,
>
>I would like to do some IR under studio conditions. I would probably use 
>HIE 4x5 to start. I'll be shooting both people and still life. My 
>lighting is Speedotron strobes and/or their modeling lights. Should the 
>lights have red gells? Should the camera have a #25? How about an EI to 
>start from? 
>
>Thanks for any help.
>
>Regards
>Richard
>
>Kodak gives the following electronic flash guide numbers for HIE 4X5: use
with a #87 or equivalent over lens. Output is first number, given in BCPS or
ECPS (if unsure of appropriate number for your flash, check mfg.
instructions; or call mfg.) The second number is the guide number.

500/40    700/45    1000/55      1400/65        2000/80

These numbers will vary somewhat depending on reflector efficiency,
room/studio conditions, etc. but they should be a good starting point. To
use, divide guide number by flash to subject distance--result is f/number.
(Electronic flash exposure is generally independent of shutter speed, so
long as shutter sychro speed is not exceeded) 
For example, suppose  a BCPS of 2000 is used at 10 feet from subject. The
guide number for this flash is shown as 80. Therefore divide 80 (g.n.) by 10
(distance in feet);;result is 8 which is the f/number suggested. This info
taken from Kodak publication no. N-17, revised 9/74 -- probably out of
print. Kodak catalog number 103-6508 -- ISBN number 0-87985-010-8. Might try
library for a copy. Hope this has been helpful. If more question re: this
message, e-mail me at jdgoff@xxxxxxxxx

Good Luck.........James


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