Hi, Ben Goren wrote:
I've wondered about that...but the grain patterns are pretty small, and there's a lot of subtle variations. I'm not sure how to line up the samples.
Well, looking at the small photo you attached, the artwork has plenty of vertices which could be used as position references. If you choose points that are (a) both reasonably smooth, and (b) near a corner for ease of identification, I'd expect that to be close enough to improve upon the vanilla scanner-profiling-chart approach, at least.
Does the i1 itself average the reading of everything that makes it through its aperture?
That I don't know. My gut feeling is that it must do to *some* extent, to cope with halftoned patches. How much this is centre-weighted, I don't know, though.
If so, I suppose I might be able to punch similar-sized holes in some paper and sample and shoot through that...
I'm not sure that's a good idea - the presence of paper in the scene, especially if it's bright white, is likely to have a subtle effect on the camera's response, especially if your lens is anything less than factory-perfect spotless. If it were me, I'd try and use the many corners and interfaces between types of wood as position references.
but, again -- would all that work get me something as good as I can get by eyeballing it, or will I still need to tweak things?
I don't know - but I guess there's only one way to find out. Taking samples directly from the artwork would at least eliminate (or greatly reduce) two of the problems you've had - namely flare on the profiling chart, and the differing spectral responses of the profiling chart and the artwork.
Hope this is some help, -- Alastair M. Robinson