Paper Negative Reversal Process

[johnielvis]

results for tungsten lights--using three par 30 halogen 75w lights (standard home track lights):

MORE apparent CONTRAST and a MUCH MUCH more "red insensitive" look to it. Somehow the "redder" tungsten lights gave a result that looked like it was lit with "less red" light--there was a red ball in both the strobe and the tungsten pics--the strobes made it look grey--kind of darker than shaded, but grey. The tungsten made it BLACK!

Also--SPEED DECREASE OF ONE MORE STOP OVER STROBES--speed needs one more stop--the similar exposure to get the same skintone was ei=0.5. These were 10 second exposures at f2.8.

Regular hot lights would give a much more favable exposure and may be better than strobes to give a more "wetplate look" to it. Time to fire up the high wattage hotlights up close and see what the best exposure time can be had....

All in all, the contrast range looks fine--there is no "contrast taming" needed--just sufficient light. The only thing that makes film superior is the faster speed.

If SOMEBODY would just come up with that source for the photobooth "super speed" paper designed for direct reversal, we would all be better off.

It's been said that Slavich makes this stuff but nobody seems to know--the photobooth people are not helpful--somehow fearful that their business will be ruined if they let out their supplier. Does anybody know where the photobooth people get their paper--The photobooth people will sell their paper but they only get it in 1.5" strips and they are not reeptive to special ordering....

[andy_k]

I'm sorry, but I don't see how a more powerful re-exposure can INCREASE the effective ei...
UNLESS you are overexposing in the 2nd exposure to the point that you're gettin solarization/partial reversal or total reversal happening...that may be the case and if it's controllable, then this may be worthwhile...

yeah, not sure if you saw my earlier posts but this is exactly it. the second exposure that i'm doing is not a fogging exposure in a chemical reversing process, but a solarizing exposure that i'm trying to control. the higher EI rating for the paper is just something that i'm estimating based on my test results as a more suitable latent image for my solarized direct reversal process (it's all done in one development, the paper never leaves the soup).

[andy_k]

i'm now quite done catching up on badly overdue darkroom projects, but as time permits me in the coming months i'll be attempting some ultra large format macro reversal images. i'll update here in the thread as progress is made.

[NedL]

I'm looking forward to reading them... I find this fascinating and hope to play with it myself eventually.

[Alessandro Serrao]

You will need Dektol, Sodium Hypo, Potassium Dichromate, Sulfuric Acid, Hardening fixer, and Sodium Sulfite.

Process:

Dektol 1:2 or 1:3 for 1 - 3 minutes DBI..
clear in Sodium Sulfite bath (about 20 g/L) 1 min
Wash 1 - 2 mins.
Bleach in Dichromate + Sulfuric acid (formulas all over APUG and elsewhere for this)
clear in above clear about 1 min
Wash 5 mins
Turn on the lights and FOG the paper front and back.
Dektol again but with 500 mg /l of Sodium Hypo, DBI again.
Stop
Hardening fix
Wash

This should work. There are many many alternates for the bleach and the redeveloper.

PE

Hi PE,
I was wondering why the silver halide solvent is in the second dev instead of the first one.

[Photo Engineer]

My search showed SCN in the FD or the SD or both. My opinion, after looking at a lot of data says it is best in the FD, but don't discount use in the SD.

PE

[andy_k]

hey PE, can you make any comment on what you think is going on in the solarization process, or point me toward some academic/scientific studies on the phenomenon? i'd like to do more than guess at precisely what it is that i was doing there.

for a progress update on the project to make a bigger camera for the purposes of this process, attempts to this point have been abortive. i shall endeavor to resolve this in the coming week.