Gary
Shooting with strobe, unless you're in a room with fairly strong ambient light, 100 ASA film won't register that light at over 1/60 @ 5.6ish, and usually if you want that aperture you're shutter speed will be lower. 3000 ASA is another matter entirely in ambient light. However, that should not matter as it's all a matter of ratios and if you use your meter correctly and your strobes are firing your film should match the polaroid no matter the speeds of each medium. If you're metering 3000 ASA film with ambient light only I'd think you'd be at 1/500@f11 (5 stops difference), again ambient light only.
It should not matter what speed your polaroid is, go by the meter unless you want to do the math in your head, which is certainly fine too. Assuming the strobes fired and your modeling lights were off the only way you'd end up with blank film is that your math is/was off. And as others have said it could be due to the fact that you can't factor shutter speed into the equation above 1/60 +/- unless you're 'dragging' the shutter to allow in ambient light.
If you'd metered @ ASA 3000 and kept the shutter speed CONSTANT and then re-metered at each respective film speed, keeping the shutter speed constant you're apeture should have gone more and more open- i.e. from say f90 to f 11 to maintain the same lighting ratio (I'm not factoring in any changes in strobe output as made by the operator).
If you were to balance or blend the strobe with the ambient (which I do a lot) you'd meter the ambient light (shutter speed AND aperture deciding on depth of field wanted) and then match the shown STROBE aperture to the ambient aperture. Strobe stays more or less constant. I usually have a ratio of strobe over ambient by 3/4 to 1 stop, i.e. ambient's at 1/30 @ f4 so I power the packs to read at 5.6 and then shoot at 5.6. It's perfect every time, based on the meter. I usually 'polameter' just to be sure it's all good, it is.
I'll be curious to hear how it pans out. Another thing to consider if you want, shoot Fuji FPC 100 proofing film (color's better and speeds more accurate) and chrome film as a test. Chrome is a LOT less forgiving in terms of latitude. Once you've nailed the chrome, B&W neg will be a walk in the park.
Good Luck
Robb Scharetg
www.scharetgpictures.com
Interesting. I'm going to give the FPC a try. I like the idea of learning with a difficult medium. It makes everything else seem easier.
Also I like the idea of using more ambient light. The trouble was that my studio was my livingroom, which is nearby one of the most heavily traveled streets on Portland, OR. I should have put a rice paper, or some other thin paper, over the windows and left the blinds open, but as it was , I had to close the blinds.
Thanks!
--Gary
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