Reversal processing confusion

[Tumbles]

I've been trying to get reversal processing to work. My goal is to be able to shoot FP4+ at box speed and have the option of processing it either as a negative or a positive. For a little while I though I might be getting things dialed in, but after 8 tries my results have stopped making any sense and the exposures are all over the map. If I compare a roll developed at 16:00 minutes to one developed at 19:00 minutes, overall the 16:00 minute roll is brighter.

Could the first developer chemistry I'm using be all wrong and bound to cause problems? I suspect that my cameras light meter might be glitching out. I've had problems in the past with the leads in the ISO dial not making good contact. When I had it overhauled 10 years ago, the technician told that the ISO dial is the only thing that isn't weather sealed. Since then it's been through dust storms, rain storms, smoke and fire, ocean spray, and getting dropped in the mud ISO dial first. So, the leads might need a good cleaning by now. Still, I've been shooing a lot of Velvia 50 and Provia recently, and I see no indication of exposure problems.

The second problem is that I'm getting all these weird marks that look like water drops. It seems like drops from one of the baths are sticking to the film in between baths, and continuing to react with the film. I try to get the baths changed out as fast as possible. I really have no idea what's causing this.

Here's all the details of what I'm doing.

1. 1st dev: Rodinal 1:25 with 2g Sodium Thiocyanate, and 250mg Sodium Bromide in 1 liter of distilled water
Development times are from 13:30 to 19:00 minutes
2. 3 tap water rinses, 10, 20, and then 30 inversions
3. Potassium Dichromate bleach, 3 minutes continuous agitation
4. 3 tap water rinses, 10, 20, and then 30 inversions
5. Clearing bath, 2 minutes continuous agitation
6. 3 tap water rinses, 10, 20, and then 30 inversions
7. 1 minute light exposure
8. 2nd developer: XTOL stock 8 minutes
9. water stop bath
10. TF-4 fixer, 6 minutes
11. A thorough rinse
12. Edwal wetting agent bath

The left has 19 minutes of development, while the right has 16 minutes. These are from ISO 12 to 400 in 1/3 stop increments. Some frames are randomly brighter, while in should be a even gradation.


The top has 13:30 minutes of development, while the bottom has 15:30 minutes.


The weird drop like marks. My Nikon Coolscan is out of commission, so this is the best image I could get.

 

[mnemosyne]

I am not an expert on reversal processes and I don't know what inspired you to use Rodinal as 1st developer, but IIRC from the few times I have done b/w reversal, the 1st developer needs to be a developer that works at high contrast (e.g. paper developer). The same is true for the 2nd developer, but maybe not as critical as long as you are able to reduce all the silver halide present to silver, it will simply require longer development times. Typical b&w film developers IMO are really a poor choice for reversal processing. I reckon the use of film developers will reduce the contrast and dmax of the resultant image and bring no benefit, as grain is usually a non issue in slide film.

 

[guangong]

For movies and slides I use Kodak D-19. Unfortunately Kodak no longer makes this developer, but formula readily available on internet. Reversal processing needs a developer much, much more contrasts than Rodinal, D76, etc.
Ilford is probably not the best film for reversal because the base itself is not totally transparent. A better choice would be Fomapan R (R for reversal), which is a movie stock with a transparent base. Available from B&H or Freestyle.
There are two ways to do second exposure: chemically or physically. For just one or two rolls, best just to wave reels ( made of transparent plastic) in front of a 60-100 W lightbul for a couple seconds.
Have fun!

 

[KPA40]

As stated before, a strong paper developer should be a better choice instead of Rodinal. Rodinal 1:25 is the standard for negatives. If you stick with Rodinal try it 1:10. Have a look at Jens Osbahrs pamphlet:

http://docshare.tips/osbahr-reversal_586f0975b6d87f604a8b472b.html

You should do the light exposure for two minutes (one minute from each side) under water in a white pot. The film can remain on the reel if you use a white plastic reel. I think the light exposure outside a water bath could be responsible for the weird water marks on your film.

Good luck, Olaf

 

[destroya]

hopefully Mr. Red will chime in. Peter is a real expert in reversal processing.

for his processs, which I have used successfully for years, uses dektol 1+2 for a first developer. I agree with those above who mentioned you need a very strong 1st developer. Also, give a chemical reversal a trry over light re-exposure. makes things a little easier. Go down to home depot and pick up a bottle of iron out.

here is a link to peter's process that I use

https://www.photrio.com/forum/threads/b-w-reversal-film-test-just-for-the-hell-of-it.113942/page-2

john

 

[Tumbles]

I used Rodinal because if remember correctly, somewhere on here I read that Photo Engineer suggested it as having a good curve for reversal processing. Some frames have a contrast range that's exactly what I'm looking for. If only I could get it to be consistent. The contrast was originally way too low until I started adding Sodium Thiocyanate.

I checked my cameras exposure against another camera and two light meters, and it seems check out. I noticed that if I wiggle the ISO dial a bit, the exposure indicator drops down into the seconds while in day light. It'll also do this if I put pressure around the battery compartment. One of the last rolls showed the ISO 400 frame being brighter than the ISO 12 frame. It's hard for me to imagine that happening without the light meter messing up.

The marks being caused by the light exposure makes sense. I'll try to do it in water. If that fails I'll go with a fogging bath. Fogging baths look like another large topic to spend some time digging through.

I'll have to wait for my FP4+ order to arrive before I can do much more with this.

 

[guangong]

For 50 or 100 ft of 16mm or Super8 I have never had any kind of marks on film by exposing outside water in the air. Although my Morris tank has a little window allowing film to be exposed to light while winding, I prefer to pass film from one reel to the other on little spindles mounted on a board and then return to tank. The 16mm and S8 reels for Lomo tanks are made of transparent plastic and I just wave them in front of the light. For 35mm and 120 still pics I use transparent Jobo reels, twisting and waving in front of light.As long as film is exposed to ligh will do. Never experienced marks of any kind from exposing to light. Nonetheless, there are times I do use a chemical exposure. But if only processing a couple rolls at a time, why bother?

 

[Tumbles]

The marks being due to light exposure is plausible to me. When I was first doing this, I was rotating the reel around a foot from the light for two minutes, and the film on the outside of the reel ended up uniformly faded. I could see the shadow cast from the leader on the rest of the film. When I exposed the film from across the room for a minute to 30 seconds, this problem went away.

The plan is to put the reels in one of those white semi-trasparent nalgene bottles filled with water, and expose it for a minute. I'm luckily working in a bathroom without any windows, and I can just turn the lights on and off.

 

[iandvaag]

A couple of points that come to mind:
- I believe that the blob-shaped mottle that you show is due to water droplets on the surface of the film during light exposure. Holding the film under water during the 2nd exposure should help, as well as possibly increasing the amount of exposure. Rotate the reel during the exposure and flip it over several times, even with translucent reels to prevent shadowing. It's hard to over-do light fogging using artificial light. I would err on the side of more rather than less. I suspect 1 min may not be enough in a nalgene translucent bottle unless you hold it close to a very bright light.
- Almost everything in reversal processing comes down to the first developer (FD), and they are very finicky. Unless you have a proven developer composition and time, you'll need to do a lot of trial and error to get an optimal result. I think agitation during the FD is extremely important and from my limited experience (~100 rolls or so); I've always had development inhomogeneities unless I agitated continuously.
- Increasing the amount of rinsing between FD and bleach may help. The bleach can oxidize the FD and cause stain.
- Reversal FDs do not last long. They should be made fresh before use and used one-shot, IMO.

Good luck!

 

[Tumbles]

The bulb I'm using is pretty bright. It's a 300 watt incandescent.

I was wondering if uneven development may have caused all that variation in the brightness across the film. Continuous agitation is something I'll probably try. I've been using the fairly standard one minute continuous inversions, and then 3 inversions every minute. I'm using a Paterson tank, and I've done continuous agitation before with the spin stick. In the past I'd though about rigging something together with a slow moving motor for continuous agitation.

I may mix some D-19 and give it a try. I have enough chemicals on hand to mix up a range of different developers. Interestingly, I did some digging around and found a post where the DR5 guy had positive things to say about Rodinal and reversal development.

This last result is really messing with my head. The left is 19:00 minutes. The right is 13:30 minutes.

 

[Tumbles]

I had some time to go at it again, and I discovered that the development is without question uneven. I shot a roll with the same shot and shutter speed. The frames in the middle of the roll are brighter, while frames at the end get darker, I have my eye on a uniroller now.

I re-exposed the film underwater, and all of the marks are now gone.

 

[Raghu Kuvempunagar]

The frames in the middle of the roll are brighter, while frames at the end get darker

If you're using a Pateson tank with adequate volume of working solution and also agitating frequently, it's perplexing why frames in the middle are brighter than those in the end. Does this happen only when you do reversal processing or does it happen even with regular b&w film developing?

Could it be an issue with your second exposure?

 

[Tumbles]

Reversal processing is the first time I've had this happen. Negatives have always been fine in this regard. I should probably look at fogging baths or developers in case the problem is in the light exposure.

I'm excited because I feel like I'm starting to get somewhere, and good results I've gotten are looking really good.