I've been doing some technical experimenting with the grdII, and am slightly confused as to whether the results have to do with some error I'm making or just the fact that digital cameras meter differently to film.
1st point: The GRD II spot meter seems to be very accurate, in the sense that it gives the exactly same iso and exposure value as my handheld sekonic.
2nd point: I'd expect whatever surface it's metering to render 18% grey on the computer.
So I take a photo of something, remember what surface I metered off, go to Aperture, do the default B&W conversion. And what happens is that the metered area is 50 % grey.
Could the discrepancy be in the Aperture conversion? I think it's unlikely to be that large.
(A further "error" I found is that my monitor renders 18% grey as about one stop off what a printed grey card looks like. But this should be beside the point.)
So the question is: Do I have some concept wrong here? OR Is the difference due to the linearity (50% !!!?) of digital vs. the non-linearity of film?
I feel like I could learn something here, but don't know where to look it up. Any clarification is greatly appreciated.
1st point: The GRD II spot meter seems to be very accurate, in the sense that it gives the exactly same iso and exposure value as my handheld sekonic.
2nd point: I'd expect whatever surface it's metering to render 18% grey on the computer.
So I take a photo of something, remember what surface I metered off, go to Aperture, do the default B&W conversion. And what happens is that the metered area is 50 % grey.
Could the discrepancy be in the Aperture conversion? I think it's unlikely to be that large.
(A further "error" I found is that my monitor renders 18% grey as about one stop off what a printed grey card looks like. But this should be beside the point.)
So the question is: Do I have some concept wrong here? OR Is the difference due to the linearity (50% !!!?) of digital vs. the non-linearity of film?
I feel like I could learn something here, but don't know where to look it up. Any clarification is greatly appreciated.