Adrian Bacon
Member
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.
That is a fantastically straight characteristic curve, AND, at ISO contrast it hits ISO 320 with a zone 1 density of 0.09 and 4 stops up from that at 0.82 density. I imagine that zone contrast would net an extra ~2/3 of a stop exposure and a dev time of about 10 minutes. Just wonderful.
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.
That is a fantastically straight characteristic curve, AND, at ISO contrast it hits ISO 320 with a zone 1 density of 0.09 and 4 stops up from that at 0.82 density. I imagine that zone contrast would net an extra ~2/3 of a stop exposure and a dev time of about 10 minutes. Just wonderful.