In camera positives by reversal processing

Рет қаралды 1,427

2 жыл бұрын

In this video I go through the process for making in camera positive images using black and white enlarger paper by reverse processing the print. I detail the process and the chemistry together with example images of each stage of the exploration.
PROCESS
1. Expose at ISO 3 + 2 stops
2. Develop to completion in standard Ilford Multigrade paper devloper for 2 minutes
3. Rinse
4. 2.5% Acetic Acid stop bath 10 seconds
5. Bleach completely approx 2 - 3 minutes
6. Rinse
7. Clear under ROOM light 20 seconds
8. Rinse
9. Redevelop also under room light to completion 2 - 3 minutes
10. Stop bath
11. Rinse
12. Fix in rapid fixer
13. Rinse
14. Dry
CHEMISTRY
Developer: Ilford multigrade paper developer 1+9
Stop: 2.5% Acetic Acid
Bleach: Part 1 Potassium permanganate 2g per liter
Part 2 Sodium Bisulphate 28g per liter
Mix 1:1 just before use
Clearing: Sodium metabisulphite 30g per liter
Fix: Ilford rapid fixer 1+4
OTHER RESOURCES
/ cameradactylcameras
/ analoguephotographytalk
/ matmarrash
/ joevca
www.photrio.com/forum/threads...
unblinkingeye.com/Articles/Nb...

Пікірлер: 14

@Dahrenhorst Жыл бұрын

Thanks for the information! I'm still in the process of doing test series to figure all that out. I'm doing that for the same reason as you, as I use a 11x14 inch camera for portraits, and film for it is very expensive and hard to find. I would have loved to see some of those 12x20" tree pictures, though.

@simonstahli1536 2 жыл бұрын

Thanks for your excellent summary! I didn‘t have much luck using the hydrogen peroxide route and am looking forward to giving this a try!

@DaveJSmith 2 жыл бұрын

Hi Simon I did also try the citric acid and hydrogen peroxide formulation, but didn't have much joy with it either so I reverted to the KMnO4 pretty quickly. I am currently trying it with RA4 paper for colour and will post a video about that once I have completed testing Dave

@simonstahli1536 2 жыл бұрын

@@DaveJSmith Looking forward to that! In the meantime I have used this process several times in my analogue photo courses - the students are loving it! It works exactly as advertised - the only issue I occasionally encountered were ‘cloudy / blotchy‘ highlights. I think it was due to not completely developing out in the first development stage (my exposures were a bit hit and miss at the beginning, because my 8x10 in camera has no shutter and I was using a black card in front of the lens while counting out the seconds ;-) ). I also suspect that the bleach has to be kept quite fresh to prevent this problem - I now use 500ml of newly mixed solution for each four 8x10 prints, and discard it after that.

@DaveJSmith 2 жыл бұрын

@@simonstahli1536 It is a fairly straightforward process once the exposure is dialed in. However, I do find the process to be very very sensitive to exposure as well as quite contrasty. The other issue that I am having is to do with the amount of blue in the light (I shoot outdoor scenes) and since paper is orthochromatic it is blue/green sensitive. I haven't come across blotchiness in the highlights yet ... maybe when I move onto the larger format! Dave

@brentdrafts2290 2 жыл бұрын

Remind me of the e6 positive print to RA paper print experiments if did for a color positive paper print.

@brentdrafts2290 2 жыл бұрын

I responded before you starting to talk about RA.. LOL.I had done some slide/e6 experiments because I had photos of my sister, who had passed away, and wanted larger framable prints. As I remember it i would crate a graded state print on 8x10 ra paper in complete darkness and then move to Kodak black and white developer for I think on minute. O then would rinse and stop and rinse again. I then would put the 8x10 under my enlarger and flash for 1 second. And then would move to ra developer at about one minute and then Blix for about a minute and then rinse and.rince. I had also experimentesd with Polaroid film negative to ra around the same time, with someone dreaming type reproduction due to the nature of the fidelity of the color Polaroid (Fuji) neative.

@DaveJSmith 2 жыл бұрын

Hi Brent Exactly so, when I do this with RA4 paper then the scene being photographed will be like the e6 slide and the paper then reverse processed! Dave

@barrykirsten7517 2 жыл бұрын

Very interesting Dave, thanks very much. I have been thinking of trying reversal again. I tried it many years ago but have since forgotten the process. I usually contact print paper negatives, which in many cases is fine, but when a laterally reversed image isn't acceptable reversal processing is a godsend. Can I just clarify one thing with you... Is it sodium bisulfATE or sodium bisulfITE in the bleach? If it's bisulfite, I understand that sodium metabisulfite can be used interchangeably. A great video, thanks again.

@DaveJSmith 2 жыл бұрын

Hi Barry Sodium Bisulphate in the bleach and Sodium Metabisulphite for clearing. I am also considering presenting these in lightboxes! Dave

@goncalomatias3506 Ай бұрын

What was the result with the ULF camera? Did you consider using pre-flash or did you where satisfied with the contrast. You may expose to light after the first stop bath.

@DaveJSmith Ай бұрын

Hi there I was exploring this process as a possible means of presenting images for the MFA in Photography, and whilst they worked out OK, I didn't rellay take to the images and so didn't take it any further, but may investigate it again for B&W processes later Dave