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I have been using the Expodev for a few years now, and it has proven to provide me with more consistancy in the negatives I produce. It seems to be working reasonably well for most situations.
However, I have encountered a condition where I cannot use the program, unless the workaround I have devised is suitable.
I have been shooting photographs in an abandoned factory, and the light levels are quite low. The darker regions of a scene are often under 0 EV. Expodev doesn't permit entering numbers under 0 EV, but I was thinking that I may be able to cheat the program by providing a compensation factor on the first screen, and then adjusting the EV readings to an appropriate in-range number. If the reading were -1 EV, then I would put the compensating factor to +1 and the reading could then be adjusted to 0 EV. Based on the formulas in Expodev, is that a reasonable workaround?
This work has also raised a larger question in my mind about how to apply the BTZS principles to nighttime scenes, and also to flash situations.
My thought is that I should do come tests for nightime exposure and development, and not try to use BTZS, since it may not be applicable to this use.
However, flash is another problem. I have two meters with flash capabilities, but they both equate the flash exposure to an f-stop only. I'm wondering if there is another method to predict the amount of expopsure that a flash produces so that it can be entered into the calculation?
I'm thinking that if the light required for exposure were converted into luminous flux (lumens) then the total lumens produced by a source (no matter the duration) would requate to the correct exposure (except for reciprocity failures). Then the flash output can be calculated in lumens, etc, so that it can be factored into the equasion properly.
Has this been done? As of this moment, I have been making exposures where I set the ambient to a level higher (1 or more EV) than the EV reading, and then manually calculate the amount of flash necessary to bring up the shadows that additional amount. I figure if I calculate the exposure correctly, the shadows will come up a bunch, but the highlights won't move too much, and it will reduce the contrast range of the scene. Then, when I process, the recorded info in Expodev is based on the composite exposure, so it should be correct.
Thoughts?
---Michael
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