From: Gregory W. Blank (gblank@bellatlantic.net)
Date: 03/08/02-08:13:35 AM Z
on 3/8/02 12:05 AM, Judy Seigel at jseigel@panix.com wrote:
> On Thu, 7 Mar 2002, Gregory W. Blank wrote:
>
>> I believe I can, Sabattier effect is akin to the Mackie Line effect(edge
>> effect) where as there is a sharp cut off between smooth transitions of
>> tonality. Noticeable where dark and light areas meet. That is you have
>> smooth change of tone on both sides of dark vs light up until the dark and
>> lighter areas abruptly meet.
>>
>> I had a teacher who stated that it is much harder to produce the reversal of
>> tonality with papers that have a less abrupt toe to shoulder transition
>> (less contrast) Fewer papers are available that are a true grade 5 which he
>> believed was important to get the Sabbattier effect.
> Gregory, your teacher was probably right about the high grade for
> solarizing *in the days when they had graded paper* but the part about the
> edge effect is wrong, as shown by Stevens & Norrish in "Border Effects
> Associated with Photographic Reversal Processes," The Photographic
> Journal, January 1937. (Tho none of this seems to address the warm vs
> cool paper issue, which was original question.)
> Even the reigning current "expert," Wm Jolly, spouted that edge effect
> business until relatively recently (along with some other "rules" my tests
> also showed not true). I learned about the Stevens Norrish research from
> the bibliography of Walker & Rainwater's "Solarization," the best
> bibliography on the process (if not the only) til that date. At the time,
> NY Public library Photo Annex had the original Photographic Journal in
> paper, crumbling a bit, but surprisingly intact, and marvelous to hold.
> Now probably in a landfill somewhere, and contents only on microfiche,
> which turns to red dot even as I write. (Am I off topic yet?)
> Anyway, to cut the suspense, the effect is caused by halation -- as is
> proved quite easily once you know to look for it -- in fact, you can get a
> "mackie line" in the middle of an area of even density, by covering half &
> re-exposing, assuming you're doing wet on wet. As I'd seen a hundred times
> before reading their report, but hadn't, so to speak, integrated. Once you
> read that, if you've done much solarizing, all sorts of other anomalies
> fall into plavr.
> This is explained at greater length (along with updated Rainwater formula)
> in P-F #2, which is how I found the G.W.W. Stevens & R.G.W. Norrish
> reference so quickly. (Under "Bibliography: Theory," page 16.) Did you
> think I had that in my head all this time?)
> best,
> Judy
Judy thanks for your knowledgable response, more things for me to consider.
I have never seen a Mackie line in my own work mid density.
However I have seen Mackie lines in the manor of my original post. Bordering
white smooth tonal change, abruptly adjacent to dark shadow area....the
Mackie line exists along the white edge you would see the line existing
actually as a seperation of both extreme values that is Black vs White.
I hope I have stated this clearly so that I am not misunderstood.
I would be intersted in reading the information you quote,...can you forward
the referenced or a way of obtaining them?
My knowledge I admit to be basic, I answered calls regarding Forte Paper
for about 6 years and did basic sensitometric testing for QC purposes
I learned alot in that time. I base my knowledge upon the Todd & Zakia
book "Sensitometery"
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