From: Judy Seigel (jseigel@panix.com)
Date: 03/08/02-11:08:44 PM Z
On Fri, 8 Mar 2002, Gregory W. Blank wrote:
> 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?
As I understand the state of libraries today, your local (or certainly a
college) library can get the printouts or the microfiche on interlibrary
loan or transfer. I don't know the exact mechanism, but I got stuff that
way from school library... (and kind of miraculous it is, even when the
machine you have to read it on is an ancient wreck).
You want GWW Stevens & RGW Norrish, "Border Effects Associated with
Photographic Reversal Processes," from the Photographic Journal,
January 1937.
I believe the librarian knows (or should) how to look up who's got (NY
Public for one) & obtain.
And well worth the trouble -- not only fascinating in itself, but
marvelous paradigm for how garbled much of our info really is (and of
course much more so in matters like gum printing, not of interest to
industry as this was, a point I may have intimated a time or two).
Consider that this info was on record as of 1937, in the Amphoto Rainwater
& Walker book by 1974, yet Jolly (et al) were still calling Mackie line
"bromide drag" as late as 1985. It doesn't look one silly thing like
bromide drag, but some version or variation of that was customary
explanation for the "edge effect." (Even by chemistry expert in the old
Photo Techniques as late as the 1990s !)
The tests to prove it was halation were ingenious -- such as exposing &
developing from the back & ... OK, I read it quite some years ago, don't
recall exactly, but nice !
Judy
This archive was generated by hypermail 2b30 : 04/10/02-09:28:54 AM Z CST