Adrian Bacon
Subscriber
For reference, and if anybody wants to discuss.
I've made these exposures as carefully as I could and eliminated as many variables as I realistically could. While it is not scientific, and certainly not up to ISO or probably manufacturer standards, it is as accurate as I can make it with what I have available to me, and certainly accurate enough that I thought it would be share-worthy.
Each of the curves is from film base plus fog up to a correctly exposed 18 percent grey card in full stop increments using a studio strobe, and transmission rated lens set to infinity focus. The strobe was incident metered to 1/10 stop and varies less than +- 0.1 stops shot to shot. The intensity of the light to the film plane was controlled with the lens aperture, so once the strobe power was set, it did not change for the duration of the exposures. The 18 percent grey card filled the frame so there shouldn't be any flare.
The densities were measured with an X-Rite Densitometer.
Since the characteristic curve is so S-Shaped, I've centered the metered middle gray at the ISO 0.9 Density point. At EI 200, you have barely 4 stops from middle grey to film base plus fog, and just a hair over 4 stops over middle grey until it pretty much stops getting more dense in any meaningful way. If you wanted to center your middle grey in the middle of the s-curve, you'd be better off at EI 160-125.
A few observations: this is not a high dynamic range film. You're looking at barely more than paper DR at 8-9 stops. That might be a good candidate for reversal processing as the film base is very clear relative to other films.
I've made these exposures as carefully as I could and eliminated as many variables as I realistically could. While it is not scientific, and certainly not up to ISO or probably manufacturer standards, it is as accurate as I can make it with what I have available to me, and certainly accurate enough that I thought it would be share-worthy.
Each of the curves is from film base plus fog up to a correctly exposed 18 percent grey card in full stop increments using a studio strobe, and transmission rated lens set to infinity focus. The strobe was incident metered to 1/10 stop and varies less than +- 0.1 stops shot to shot. The intensity of the light to the film plane was controlled with the lens aperture, so once the strobe power was set, it did not change for the duration of the exposures. The 18 percent grey card filled the frame so there shouldn't be any flare.
The densities were measured with an X-Rite Densitometer.
Since the characteristic curve is so S-Shaped, I've centered the metered middle gray at the ISO 0.9 Density point. At EI 200, you have barely 4 stops from middle grey to film base plus fog, and just a hair over 4 stops over middle grey until it pretty much stops getting more dense in any meaningful way. If you wanted to center your middle grey in the middle of the s-curve, you'd be better off at EI 160-125.
A few observations: this is not a high dynamic range film. You're looking at barely more than paper DR at 8-9 stops. That might be a good candidate for reversal processing as the film base is very clear relative to other films.