Sunday, April 17, 2011

My BW Reversal Process

Updated: Apr 17, 2012

Well, this is a journey that I started 2 years ago. The hardest part was finding sources. Nothing seemed to come together until about a month ago. I am either patient, persistent, stupid or nuts. It’s probably some combination of all the above. I have now attained success and it is time to document it. I update the information as I discover new things.

If you have arrived looking for directions on how to do reversal processing, take my process with a grain of salt. Like all the others, it is a modification (ultimately) of Ilfords document on the topic. I am not a chemist and much of what I changed was based on what I could decipher from the little good information I have found on the net. Lots of people will voice their opinions and little can tell you why they suggest such. I will give my reasons for ending up where I have. Use your brain; if it does not make sense to you then don’t do it.

For me, reversal is the end of the search for the perfect process and I will likely only develop negs again for special occasions. My first 6x9 put the icing on that cake. They are fine grain, great detail and great contrast. A scanners dream.

Before attempting to do it from scratch, I suggest trying a kit. Doing this scavenger hunt for materials would be a bit of a bust when it is just a passing phase. I tried the Foma kit with their 100r film and was impressed.

The process is quite simple. Develop, wash, bleach, clear. wash, flash, develop, wash, fix, wash, wetting, dry.

For reference I use a motor base that uses 150 ml of solution to cover the film. Development is at 20c. Rinse water is kept in jugs to insure even temp between all chemicals. Distilled water is used to make all chemical solutions, including diluted developer. Except for fixer, this is a one shot process.

1st DEVELOP:

Ilford suggests paper developer. You need a very active high contrast developer. At first I tried D19 (as per Kodak kit), but had to use too many additives to make it active enough. I settled on Dektol because it is cheap requires the least additives available and has worked the best so far.


You do not need a fine grain developer at this stage. Just an active one. What gets developed gets bleached/cleared away. Don't get distracted.

You need to add hypo to the developer to flatten the density curve and will change with every type of film you use. I am a film hoarder (just not on TV and no current support group) and I do not like to limit myself. I chose to make a hypo solution to use as a additive in the one shot process.

My hypo solution consists of 8g hypo added to 250 ml water.

The first developing process is where most of the adjustment is achieved. A starting point of 1:2 for Dektol + 9 ml hypo solution for 12 mins of continuous agitation. If there is not enough contrast, try 1:1 Dektol. If the images are too dark, increment hypo by 3 ml amounts. Scale to your tank volume size.

WASH:

5 inversions of water then dump.
10 inversions of water then dump.
20 inversions of water then dump.

BLEACH:

Potassium dichromate 6,0 g / 1000 ml (part a)
Sulfuric acid conc %20. 1:19 dilution (part b)

I use Dichromate because I can get it without any unreasonable interrogation or MSDS fees. No other reason.

I use %20 sulfuric acid because that’s all I can get. It is not a big deal as it gets diluted anyway. It is lab quality, so it is all good.

You may notice that this is about ½ the dilution of other formulas. This has reduced the problem of the emulsion lifting off the base. Feel free to reduce more. Stretch the times if needed.

I mix 75 ml (a)+75 ml (b) and continuously agitate for 5 mins.

You have enough bleaching when the parts of the film that was fully exposed are clear. The leader on a 35mm strip should be clear as it was exposed to light during the loading of the film. For MF, remove the lens or open iris and shoot into the light for 1-2 secs.

This should have the capacity of about 4 rolls. It does not have a long shelf life mixed, but I have used the same batch over a couple days.


WASH:

5 inversions of water then dump.
10 inversions of water then dump.
20 inversions of water then dump.

CLEAR:

Mix 30 grams of sodium metabisulfite with 1 litre of water.

Measure 150 ml and continuously agitate for 5 mins.

This should last longer than the bleach when good whashing is practiced. However I mix the bleach and this before disposing to nutralize the bleach.

WASH:

5 inversions of water then dump.
10 inversions of water then dump.
20 inversions of water then dump.

FLASH:

Carefully remove the film from the tank, holding the strip stretched between your two hands. Hold it about 2 ft from a regular light source (100 w bulb or equiv) for about 1 minute on each side. I slowly sway back and forth to insure even exposure. You will figure out what works. Blacks may become faint with uneven exposure.

You should see some images surrounded by the unexposed emulsion. In time, you can gage how much is needed.

Re roll the film onto the spool and place it back into the tank.

This and the next step can be replaced with a fogging developer. There is a post here on how to do that.

2nd DEVELOPER:

150 ml of Dektol 1:2 for 5 minutes. You are developing to completion. If your film borders are not pure black, increase this time accordingly.

WASH:

5 inversions of water then dump.
10 inversions of water then dump.
20 inversions of water then dump.

FIX:

Try to use a fix with a hardener. This process is hard on the emulsion. It does not need much, as all the silver should have been developed/stripped before this. I give at least 5 mins for the hardening. This fix is reusable.

WASH:

 5 inversions of water then dump.
10 inversions of water then dump.
20 inversions of water then dump.

WETTING AGENT:

Photo-Flo and dry.

FILMS:

FilmEI1st devHypo1st Dev TimecommentsDMax
Lucky SHD100Dektol 1:26 ml12 minsurprisingly good, sharp
Foma 100R100Dektol 1:29 ml12 mingood high dr high contrast
Neopan 400400Dektol 1:212 ml12 mingood sharp
px100Dektol 1:26 ml12 minBase for all comparisons.
Foma 100100Dektol 1:1012 minFantastic
2
ORWO UN54100Dektol 1:2512 minGreat, really smooth
ORWO N74+400Dektol 1:1512 minGreat


NOTES:

Observe local disposal laws with the above chemicals.

Dichromate is an oxidant and you should adhere to normal precautions when dealing with such a substance.

Request MSDS documents whenever ordering your chemicals. They will contain any best-practice handling instructions for that product.

3 comments:

  1. Great post. I came up with the exact same process some time ago, when I wanted to develop b/w movie film at home... Try it with paper, I've done some experiments, it's quite unreliable but something happens (well, if you want to get paper negatives from a negative, or positives form a positive). Thanks for the info on different films, I was looking for cheaper alternatives to Ilford PanF+ (which is AWESOME in reversal processing).

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  2. The only hard film so far is acros 100. Not even close to anything usable yet, unlike the Neopan 400. I'm going to try a different silver solvent on that one.

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  3. This is just what I was looking for!
    Yesterday I was developing Adox Pan-X Reverso with Fomadon R09 (without hypo) as a first developer (7 minutes). Pictures are too flat without hightlights, with big grain. Have you any experience with Adox?

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