I'm following this discussion because I have a holder for slides
for the 4x5 enlarger and I'd like to make some b&w prints of the
slides.
On Fri, Aug 13, 2021 at 3:07 PM `Richard Knoppow <dickburk@xxxxxxxxxxxxx>
wrote:
When I first got an 8x10 camera I had no film. I cut down for
paper to fit the holder and experimented. It took a very long
exposure, don't now remember how long, but I got a negative and
contact printed it. I still have it somewhere.
I don't remember what lens I had then, for some reason I
think it was a Turner-Reich, a perfectly awful lens I picked up
somewhere.
On 8/13/2021 3:01 PM, Laurence Cuffe (Redacted sender cuffe for
DMARC) wrote:
wrote:
On 13 Aug 2021, at 22:35, `Richard Knoppow <dickburk@xxxxxxxxxxxxx>
information, not a lot, in the old literature on reversal processing. The
Good on you! I was going to add just a little. There is some
process really has to be tailored to the specific material although the
fundamentals are the same. Many reversal first developers have a small
amount of halide solvent in them, sometimes thiosulfate but often
thiocyanate. The idea is to eliminate the slight fogging that causes a haze
on the reversed pictures. Also, the second developer is usually a very
active developer, like Dektol. The grain is evidently established by the
first developer so using an active reversal developer does not result in
large grain. Also, the reversal can be done using a solution of sodium
sulfide, essentially the same stuff used for redeveloping two step sepia
toner. Of course, the images are sepia colored.
some of its old processing and chemical booklets.Kodak has formulas for reversal development of printing paper in
common but I don't remember if I ever saw published formulas for theReversal processing of 8 and 16mm motion picture film was very
process.
halide in it to make sure there is enough to produce full density of theAnother note: film designed for reversal has an excess of silver
final image. Motion picture film for projection must have rather high
density and contrast to avoid looking washed out. Probably the same for B&W
slides.
have with reversal, either film or paper, and, to be clear, on anyI would invite reporting on any practical experience list members
experiments done. It is a fascinating process and, like monobath, not
widely practiced.
I will take a trawl through some of my older literature as well. I hopeto get something that will work with paper, for when I’m using paper as a
sensitive material in my 8x10. this is a summer project, and more long
term I’d like to play with film. Using paper to start off with means I can
monitor the process with a safelight, which might reduce the amount of
phafing around involved in getting to a working process.
All the bestwrote:
Laurence Cuffe
On 8/13/2021 12:55 PM, Laurence Cuffe (Redacted sender cuffe for DMARC)
ended up doing a full copy onto an old disk drive and a further copy of myDear All,
Just after I posted this query, my computer started acting oddly, so I
pictures library onto another disk drive. they were old mechanical drives,
so this was not a fast process, hence my delay in responding.
about Gainers formulas and reversal processing.
Many thanks to the following:
Luis Miguel Castañeda,
Terry Hosinger,
Karstwalker,
Titrisol,
and Nicholas O. Lindane for their very prompt responses to my queries
on the web he seemed to be a very likeable, knowledgeable and generous man.
It was all very useful.
Luis, Thanks for the upvote for Patrick Gainer, from what I have found
The use of Sodium Bisulfate 25g/l as a substitute for sulphuric Acid,
Terry, That was exactly the information I was looking for on reversal.
10ccConc/l.
https://web.archive.org/web/20180225015603/http://silent1.home.netcom.com/Photography/Dilutions%20and%20Times.html
Karstwalker Thankyou for the same information, and the link.
Titrisol, Thanks for another upvote for Gainer, and the link:
<
https://web.archive.org/web/20180225015603/http:/silent1.home.netcom.com/Photography/Dilutions%20and%20Times.html
there, which will require close reading and some exploration in the
to Donald Quall’s DonaldQualls collection of recipe’s some good stuff
darkroom.
routinely sell Sulphuric acid. My local Halfords stopped doing it in 2018,
Finally Nicholas. Over here in Ireland, Autoparts stores, do not
as owning Sulphuric acid in the UK now requires an explosives precursor
licence. The Irish stores are subsidiaries of the UK firm. I can source it
as drain cleaner, but I’m a bit leary of doing that, because I don’t know
what else is in there, hence my query. I think with the help of everyone
who contributed here, I’m now good to go. thanks again all,
<mailto:nolindan@xxxxxxxxxxxxx>> wrote:
All the best
Laurence Cuffe
On 12 Aug 2021, at 20:40, Nicholas O. Lindan <nolindan@xxxxxxxxxxxxx
You can get sulfuric acid at the hardware store as acid drain cleaner but
Sulfuric/battery acid should be available from the autoparts store.
it has additives to keep if from attacking metal pipes. Or, you can order
it from Photographers' Formulary or ebay. The battery acid stuff is 35%
(IIRC) and less nasty than the ~90-98% 'concentrated' form.
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