Re: Ilford Multigrade IV vs. Kentmere Fineprint?

Nicholas O. Lindan wrote:
...> http://www.ilfordphoto.com/download.asp?n=34&f=20061302013402375.pdf

I wouldn't put much faith in the published curves. The reality is
very different.

I think I would trust published curves by the manufacturers; I have found
them usually accurate. The main problem I find is they are not precise
enough; i.e., they are too small to be read meaningfully. Also, with these
VC papers, the manufacturers plot them differently. Some let the curves
intersect at density 0.2 to 0.4, which could be useful (e.g., Kentmere) and
others let them intersect at a density of about 0.7 (around Zone V), which
is useful in a different way. But doing this makes comparison's very difficult.

Darkroom Automation http://www.darkroomautomation.com/index2.htm
publishes paper speed data for use with its enlarging meters and
timers:

http://www.darkroomautomation.com/support/mgivfbhd.jpg
http://www.darkroomautomation.com/support/mgivrchd.jpg

I don't have data on Kentmere VC, but I doubt that the curves don't
also resemble roller-coasters.

VC paper has two problems:

o A hill-and-dale response at low contrast grades

I do not know how important that is. I have recently bought a box of the
Ilford paper (since I liked their graded Galerie paper in the past). I put a
Kodak T-14 step wedge in my enlarger and then made prints with a lot of
different settings on my cold light head (two tubes with one green and one
purplish blue. I did not plot points close enough to see hill-and-dale
response (I am not saying it is not there, just that I did not notice it).
I think I see what you mean on the Ilford curves between densities 1.0 to
about 1.3. I have made only a few "real" prints and do not notice it.

o Highlight contrast that doesn't change much with paper grade

This is clearly shown in the Kentmere curves where they plot them to
intersect in the very high zones (VIII and IX), but less clearly in the
Ilford curves where they intersect at about zone V.

The problems are inherent to the principle by which VC paper works.



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