How's My Reversing? (Tri-X Reversal 7266 in D19)
Tri-X Reversal in D19. New EI/dev time tests. Stock at 20C.
You can see that even by 12m I have just reached a usable 100ASA. Increasing from 4m to 8m appears to give a one stop speed increase, The step from 8m to 12m did't gain that much. I estimate that I need 16m to get 200ASA.
The standard (most common) times for this combination seems to be 200ASA dev'd for 6-7mins in stock solution (source: numerous internet samples and anecdotal evidence even on this forum).
Why do I appear to need 2x or 3x the development to get a 'normal' 200ASA result for this film/dev combination?
(And seems interesting in light of the similarly dark positives I was consistently getting from Tri-X 35mm tested in PQ and Liquid Dektol)
Could there be something I am getting consistently wrong in my process (Permanganate bleach/Clearing sol from Foma kit. Same developer at half duration for 2nd dev)?
[You should be able to click through these to get zoomed in version:]
NB. Let me add that I'm pleased to be getting towards decent results but feel that something doesn't quite add up.
Last edited by mr.datsun; 03-11-2013 at 07:20 PM. Click to view previous post history.
thanks, that's a lot of ideas. There are two that interest me to start with.
1. 'everyone elses times always 6 minutes. the 6 minutes is for people adding hypo probably'
Can I ask what you meant here in a discussion of Tri-X Reversal in D19, when you said of yourself using D19 to process Tri-X Super 8 :
'I used d-19 to develop --- straight d-19 for 6' about' ?
I presumed that you meant you were using it without hypo there. What EI index did you get at 6 mins when you recommended that time?
2. 'it sounds counterintuitive, but some developers need to be dliuted with water to get more power'
Yes, it does a bit. Can anyone else confirm this?
(btw, I started at 1+1 for 4mins and got very dark positives compared to 1+0 at 4mins)
If you don't want to use a more concentrated developer and you don't want to increase time/temperature of the first dev, then trying a silver halide solvent would be easier than adding another bleach step (which implies using a clear bath after) after 2nd developer. This will reduce the density a little (which you want) creating a brighter image.
Once in the ballpark of the right amount to add (usually between 1 and 5g/L), you can even control the ''tone'' of the image. If the scene is contrasty add a little less and increase 1st dev time, if it is not contrasty enough add a little more and decrease 1st dev time.
That's what I've been learning since a few weeks and it works for me. Silver halides aren't necessary, but they can make things easier...
Thanks for the encouragement, guys. I've been looking at my camera shutter speeds and reading the literature so have been quiet on this. I've come to decision on Tri-X Reversal 7266.
After work commitments I have limited time. Tri-X experiments are now becoming an impediment to my project and my pleasure. It's a drain on time and energy and not giving anything back.
I've followed the processes that other have used successfully (Rodinal and D19 for example and I also tested PQ and Polymax(Dektol) ) and just not got the results. I do believe it should be possible to replicate other's process within acceptable limits. With the speed loss i am seeing, it looks likely that I am doing something wrong but still do not know what but can't expend more time worrying about it.
Thanks both for your ideas above, but I feel that I cannot spend another two weeks testing new chemicals* and processes as a workaround to fix something that should work without – and has worked without for many people. When I used Tri-X Super 8 many years ago with the Tetenal Reversal kit it was great. It looked wonderful and worked first time and every time. Today, at this particular moment, processing Tri-X Reversal film feels like flogging a broken horse from where I am.
But I do have to develop the film myself for the pleasure (I actually enjoy it) and the process. It really needs to be part of my film work. So I'm looking at reversal films like Scala 200x and Adox Pan-X 100 to get out of this fruitless Tri-X loop, at least for the time being. I already have a cartridge of Adox Pan-X Reverso in the fridge and might run a few test strips this weekend. If that also fails then my method is wrong somewhere and I need to look at that again. If it succeeds then Pan-X might be a better short to mid term solution leaving the Tri-X Reversal mystery behind me.
(Also I have been hoping that Adox will get their Pan-X Reverso reversal kit out soon)
The speed rating of TriX Reversal is not really an issue. Tri-X is panchromatic, afaik. The dual film speed rating is surely to account for cameras which have a tungsten 85a filter built in. The Tri-X cart auto switches it out on my camera. But I'm also exposing manually with a Weston using incident reading and using 32k Bowens light.
My camera shutter speed at 18fps single frame is accurate and so is my Weston meter tested against two camera meters. So I still read my best result as 100ASA at 12mins max strength developer. So if I can only get 50-100ASA from Tri-X I might just as well use another true reversal film. One with a clear base, to boot.
*With what you explained to me and now I've read the document 'A Black&White Reversal Process In Memory Of Agfa Scala 200x' I think I'm much clearer on the silver solvent question. It's more important with low speed films. I think with a fast film like Tri-X and it's thin emulsion it only serves to make the whole image too weak at 1st dev stage.
'The amount of silver solvent needed depends on the amount of silver halide in the film and the strength of first development. In principle, lower speed films contain a higher amount of silver halide; they are more capable to build maximum densitiy in the negative. A lower amount of developer concentrate in the first developer creates a softer negative image and leaves more unused silver halide requiring more silver solvent and vice versa.'
Last edited by mr.datsun; 03-14-2013 at 09:29 PM. Click to view previous post history.
In fact b&w film is less sensitive to tungsten light than to daylight. Like Fomapan, it is 80ASA in tungsten light. It has nothing to do with 85 filter.
Originally Posted by mr.datsun
Yes but currently your film is too dark, so you want to reduce density somehow, possibly with with silver halide solvents.
Originally Posted by mr.datsun
I'm looking forward to your tests with Adox PanX !!
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I read that somewhere but then I wondered why negative films do not, to my knowledge, have those same dual speed daylight/tungsten ratings?
Originally Posted by Tofek
Well, in my case even minute amounts of the silver solvent solution seemed to reduce density evenly all over the tonal range without any increase in contrast. That paper seemed to offer an explanation to me but I may be interpreting it incorrectly.
Originally Posted by Tofek
Yes, I'm looking forward to the Pan-X tests. When I have something to show, I'll post.
I think negative behaves the same as reversal with tungsten light and daylight except the difference isn't that noticeable since negative is very forgiving. For example the sensitivity of Efke emulsions was for tungsten light, and not daylight : you had to underexpose by one stop in daylight. I didn't know it at the time when I used some but I have great prints from it. The negatives are bullet proof though, especially in scenes under bright sun...
Thanks for clearing that one up. I was confused.
Originally Posted by Tofek
Thanks - I'm clear on the film rating issue now.
Originally Posted by johnielvis
Yes, a lab processed Tri-X might be good idea as a benchmark.
I've got 4 carts of Tri-X in the fridge - so i'm not really saying goodbye, Tri-X, so much as 'Au revoir Tri-X and bon matin, Pan-X'.
The change might shed some new light on my processing.
I don't think that the loss of speed due to fog being developed in the 1st dev. If fog had been created in the 1st dev, it would have been bleached away thus resulting in a brighter image. It's the opposite.
It is rather that all the negative silver isn't developed and thus isn't bleached. There are some silver halides left in the transparent parts because they haven't been developed as negative. The fog is created in the 2nd dev, because too much silver is left in these transparent parts. That's why a silver halide solvent would help to gain speed.