Closer But Still Not Offical - Grade Determination

[dancqu]

Not official grade determinations but I think interesting
and useful for comparative purposes. The method employed
used a Stouffer 21 step step wedge; image projected upon
sample 5x7 sheets. Each of 4 papers were tested in a low
and a high contrast developer. All Grade 2 Glossy FB.

Beer's 1, a low contrast Ansco 120 type. Contrast Range:
Arista Classic, 2 1/4 to 2 3/4; Emaks, 1 1/2 to 1 3/4
Kentmere Bromide, 1 to 1 1/4; Slavich, 3 to 3 3/4

Beer's 7*, a high contrast Dektol type. Contrast Range:
Arista Classic, 3 to 3 3/4; Emaks, 2 1/4 to 2 3/4
Kentmere Bromide, 2; Slavich, 4 to 4 1/4

David Vestal's edge method of grade determination was
used. "The method that worked best ... in good light ...
count every visible edge between steps". His table
of values takes into account the elongation of the
Exposure Scale at low grade values. Something
I had not done in prior posts. Some may note
that it is the very low contrasts that have
disappeared from the above most recent.

*I use developers very dilute, the 7 blend is no exception.
Beer's 7 is though specified undiluted. The other blends
are 1:1 with water. My dilutions any of the 7, 1:7.

VC paper users should see additional contrast control
possibilities using one of a few contrast control
developers. Dan

 

[Photo Engineer]

Dan;

Good work. I took David's course. He is an amazing person. I got a nice card from him with a beautiful photo.

PM or e-mail me. I might be able to help. Also read Post Exposure by Ctein.

PE

 

[dancqu]

Comparative Paper Speeds

Taking each step of the Stouffer step wedge as
a half stop the approximate comparative speeds of
the four papers in half stops are:

Beer's 1 -
Emaks, 0; Arista, +1; Kentmere and Slavich, +2
So Emaks is slower than Kentmere and Slavich by
one stop.

Beer's 7 - Incomplete data

The only out of line results were the Slavich; Beer's
1 to 7, grades 3 to 4 1/4. Wrong label? BTW Arista
Classic is no more, at least by shopping Freestyle.
My guess, Slavich and Emaks; both with Graded
FB and one with a SW to boot. Whence the
Arista? Likely England. Dan