Studio IR film Help

[eddiefisher]

Hey Guys.
Thought id post this on here seeing as i had 150 views but zero responces to my post on another forum!

Next month i will be doing an IR set in the studio.
I have the Cokin IR 89B filter and plan on using Kodak IR film or the not so true Ilford SFX 200 film. The Kodak has not gone upto £17 per roll after it was discontinued.

My question is does anyone know exactly how many stops the 89B will reduce my exposure? Ive heard 5 or 7 stops but dont want to waste the whole studio session with bad exposure.

When im in the studio i usually use my 85 and 50mm f1.4 primes and usually use ISO100, 1/160 and about f8. In terms of exposure im guessing that shutter speed is out the window here as its studio strobes. Should i be using f1.4 which is 5 stops compensation? Id rather bump up the film ISO to perhaps 400 so that i can use an apperture of f2.

I do however have the option of using more lights, the studio is quite well equiped so i could double up lights in the lighting rig and use them on full power, probably about f32 in terms of light output.

Any thoughts?
I unfortunatly wont have access to the studio to do a test with a roll of film as i rent the studio.
Thanks.
Ed

[doenoe]

IR as in Infrared? How are you going to get that kinda light in a studio? Im just being curious here, cause i havent got a clue about shooting IR on film. So maybe you can get terrific pics indoors, but i just havent got a clue

[eddiefisher]

Yeah, ive seen some great stuff that people have done in the studio with Infra Red.
This for example:


Studio strobes do tend to cick out a fair bit of IR radiation, hence the heat but my post is really to do with filter compensation.
Cheers

[eddiefisher]

Bump

[frXnz kafka]

I think it would really depend on your lights. I don't know much about IR but I assume different lights give off different amounts of infrared light. Your best bet would probably be to book a short session in the studio and pop off a test roll. It'll cost more, but you may end up having to book an extra session anyway if you mess up your exposures. Or you could just bring plenty of film and do a lot of bracketing.