B&W reversal: Thiocyanate or Thiosulfate

[Raghu Kuvempunagar]

I saw that, but Im not sure if he is referring to the 100 and 400 film or the way to expose them... I think youd need an extra stop. The folks in this thread followed the recipe:
https://www.photrio.com/forum/threa...mulary-reversal-kit-and-tmax-400-tmy-2.74132/
But are giving it more light.

Ok, if this is indeed the case with the Dietrich's developer for TMax 400, then it doesn't reflect too well on its formulation:

"regardless of the ISO the general appearance of the negative seems to be too dark, and underexposed."

That's a bit surprising to me given the high level of thiosulphate in the formula. And Dietrich talks about of getting DMin of 0.3 and DMax of 2.6 which is very decent.

 

[pkr1979]

I dont know though. And you might have a point Raghu... would you shorten the first developer time if using thiocyanate instead of thiosulfate? Maybe its better to use thiosulfate... but avoiding fogging and loss of shadow density is something Id like to do.

 

[Raghu Kuvempunagar]

I dont know though. And you might have a point Raghu... would you shorten the first developer time if using thiocyanate instead of thiosulfate? Maybe its better to use thiosulfate... but avoiding fogging and loss of shadow density is something Id like to do.

It's possible that because of the high amount of thiosulphate in the first developer, there is a loss of emulsion speed. Nevertheless, my suggestion to you would be to make no changes to Dietrich's recipe and follow the instructions exactly. I would shoot a small test strip of bracketed shots properly metered, see what Dietrich's process gives me and make changes to, one variable at a time, based on the results. I would base my EI on that speed which gives the right shadow detail in the test strip. If slides turn out to be a little dark overall at this EI, I would extend the time in first developer a little. Till I have done this, I wouldn't try anything else as it gets complicated very soon.

 

[pkr1979]

I know you are right, but its very tempting to switch to thiocyanate I have 2 exposed rolls... one tmx at 25, 50 and 100, and one tmy2 at 100, 200 and 400. The chemicals Im lacking are on the way. As soon as Ive tested I’ll report back - I’ll let you know then if I’ve used thiosulfite or thiocyanate

 

[gorbas]

Thank you Raghu for the link! Appreciated!
Yesterday I did take look at my old literature (German ORWO, USSR and Yugoslavian) and nobody even mention thiosulphate in first developer. All recipes but one is talking about using thiocyanate. One is omitting silver solvent at all.
With out numerous test clips I will never attempt to do BW reversal. When I did my processing with home brew ORWO #829 developer with out thiocyanate and EFKE KB17 film (box speed 40iso), under tungsten light, I ended up with EI of 100 or 125.

 

[relistan]

Thank you Raghu for the link! Appreciated!
Yesterday I did take look at my old literature (German ORWO, USSR and Yugoslavian) and nobody even mention thiosulphate in first developer. All recipes but one is talking about using thiocyanate. One is omitting silver solvent at all.
With out numerous test clips I will never attempt to do BW reversal. When I did my processing with home brew ORWO #829 developer with out thiocyanate and EFKE KB17 film (box speed 40iso), under tungsten light, I ended up with EI of 100 or 125.

If you are looking into this, you might be interested in the Ilford reversal instructions for their films: https://www.ilfordphoto.com/wp/wp-content/uploads/2019/06/REVERSAL-180619.pdf

They recommend the following:

To the working strength developer add sodium thiosulphate crystals (Hypo)–as a guide, for PAN F Plus add 8g/l, and for FP4 Plus and100 DELTA Professional add 12g/l
​

As @Lachlan Young said earlier, if you are using permanganate bleach (Ilford recommends it in that pamphlet), you really don't want any cyanide in the bleach, so avoiding thiocyanate makes sense.

 

[Raghu Kuvempunagar]

I
As @Lachlan Young said earlier, if you are using permanganate bleach (Ilford recommends it in that pamphlet), you really don't want any cyanide in the bleach, so avoiding thiocyanate makes sense.

Isn't HCN is formed even when peroxide bleach reacts with thiocyanate?

 

[Anon Ymous]

I've always used permanganate bleach and potassium thiocyanate in FD, but I always wash very well between these two. I do 4 water changes after FD, with adequate agitation. Needless to say, you do this at your own risk.

 

[relistan]

Isn't HCN is formed even when peroxide bleach reacts with thiocyanate?

Yes I think you previously linked a thread about that with PE and Rudeofus taking about it.

 

[pkr1979]

Slightly off topic but how do I send private messages?! I even have some conversations Ive started but I have no clue how I did that.

 

[MattKing]

Slightly off topic but how do I send private messages?! I even have some conversations Ive started but I have no clue how I did that.

Due to some recently incorporated changes you probably can't send private messages until your post count increases. The changes are there to deal with a problem with new members who join to scam others.
If someone else sends you a message (Starts a Conversation) you can participate, so it would probably be best to post in this thread a request to a member to start that Conversation with you.
You could also contact a moderator by "Reporting" your own post and making a request. I believe that they can help you.

 

[pkr1979]

Thanks Matt. Raghu or gorbas, could either of you send me that Haist pdf?

 

[relistan]

Thanks Matt. Raghu or gorbas, could either of you send me that Haist pdf?

I have messaged you

 

[pkr1979]

Thanks a lot for those files

 

[gorbas]

There are lots of interesting files on that link! Enjoy!

 

[YoIaMoNwater]

I'm a bit late to this thread but I tried to reverse a Tmax400 @ 3200 in Microphen and the end result was as expected: very dark (film leader and also border markings are quite dark). This reversal method worked great for Rollei Superpan 200 and Fomapan 400, but it seems like Tmax definitely needed a silver solvent in the first developer. I would be interested to see if you manage to find a working percentage for this particular film.

 

[pkr1979]

I'm a bit late to this thread but I tried to reverse a Tmax400 @ 3200 in Microphen and the end result was as expected: very dark (film leader and also border markings are quite dark). This reversal method worked great for Rollei Superpan 200 and Fomapan 400, but it seems like Tmax definitely needed a silver solvent in the first developer. I would be interested to see if you manage to find a working percentage for this particular film.

I’ll post here as soon as Ive developed.

 

[Lachlan Young]

I'm a bit late to this thread but I tried to reverse a Tmax400 @ 3200 in Microphen and the end result was as expected: very dark (film leader and also border markings are quite dark). This reversal method worked great for Rollei Superpan 200 and Fomapan 400, but it seems like Tmax definitely needed a silver solvent in the first developer. I would be interested to see if you manage to find a working percentage for this particular film.

Or a development accelerator in a much more active first developer - an EI of 800 on TMax 400 is achievable in the Agfa Scala process.

 

[YoIaMoNwater]

Or a development accelerator in a much more active first developer - an EI of 800 on TMax 400 is achievable in the Agfa Scala process.

Is there any example images of reversed TMax400 on a lightbox? I'm just curious because I couldn't find any online. The reversal process I tried resulted in the film leader to be very dark/gray, even the border markings are quite dark. I'm wondering if it's necessary to add a silver solvent since I read somewhere that TMax400 has some silver halides deep within the emulsion that's hard to be bleached.

 

[Lachlan Young]

Is there any example images of reversed TMax400 on a lightbox? I'm just curious because I couldn't find any online. The reversal process I tried resulted in the film leader to be very dark/gray, even the border markings are quite dark. I'm wondering if it's necessary to add a silver solvent since I read somewhere that TMax400 has some silver halides deep within the emulsion that's hard to be bleached.

I've got Delta 400 in 120, run in the Agfa Scala process (which as far as I know uses PEG 1500 as the accelerator, but no additional KSCN or similar solvents - although the patent that discloses this also refers to novel inventions in first developers using HQMS-K, KSCN and PEG 400) - no TMax immediately to hand.

 

[YoIaMoNwater]

I've got Delta 400 in 120, run in the Agfa Scala process (which as far as I know uses PEG 1500 as the accelerator, but no additional KSCN or similar solvents - although the patent that discloses this also refers to novel inventions in first developers using HQMS-K, KSCN and PEG 400) - no TMax immediately to hand.

I understand 120 format has a film clear base, which isn't true for 35mm (except specific ones like Rollei, etc). That's why I'm curious on how 35mm reversed BW film look to the naked eye. I feel like that's the best way to judge this reversal process without a densitometer as scanned photos are either auto white balanced or level corrected.

 

[Raghu Kuvempunagar]

This what DR5 says about TMax 400:
" Do not shoot this film at its factory speed for dr5! The quality is substandard at iso higher than 200. The normal iso for this film in dr5 is 125iso. TMAX400 can not be run at 400."

DR5 doesn't use halide solvent.

 

[Lachlan Young]

I understand 120 format has a film clear base, which isn't true for 35mm (except specific ones like Rollei, etc). That's why I'm curious on how 35mm reversed BW film look to the naked eye. I feel like that's the best way to judge this reversal process without a densitometer as scanned photos are either auto white balanced or level corrected.

They'll probably look OK - they will look a little greyer if viewed alongside a clear base film, but not as much as you might assume from viewing a negative of the same emulsion developed in a solvent developer. The choice of clear base will have likely been for the simple reason of making the transparencies look as good as possible when viewed alongside E-6 transparencies on a light table - BW cinema reversal stock is on a grey tricaetate base - the eye adapts surprisingly well if it has no other reference.

I also have significant issues with your experimental design - Microphen is a poor choice because of its lower activity (great for making nice negs) and built-in mild solvency. What you really need is a highly active, low fog developer to slam development to completion as efficiently as possible, to which you add just enough solvent and/ or accelerator to ensure that developer can access all the silver very quickly - as your first development time goes up (in reversal) Dmax drops due to fog, and if you cannot access and develop all the silver, your Dmin rises too.

This what DR5 says about TMax 400:
" Do not shoot this film at its factory speed for dr5! The quality is substandard at iso higher than 200. The normal iso for this film in dr5 is 125iso. TMAX400 can not be run at 400."

DR5 doesn't use halide solvent.

I recall reading that Kodak D11 was what Mr Wood claimed was a good choice for reversal FD. It has 75 g/l of sulphite which is not far off that of many developers that would be considered mildly 'solvent'. The problem may be that there is a disconnect between the necessary developer activity and solvency/ silver access in films that have much tighter grain structures than HP5. Sulphite, while a silver solvent, is slow working in comparison to various other additives for solvency/ acceleration. Essentially what he's admitting is that his system cannot access the silver fast enough to develop it before overall fog grows to a level that kills Dmax. That level of sulphite may also be enough to effectively act as a monobath with extended developing times on some document films, wrecking their chances of giving a good reversal.

 

[relistan]

I recall reading that Kodak D11 was what Mr Wood claimed was a good choice for reversal FD. It has 75 g/l of sulphite which is not far off that of many developers that would be considered mildly 'solvent'.

Interesting, looks like it's not that far off D-72 1:2 which is what a lot of people have used. https://www.photrio.com/forum/threads/kodak-d-11-developer.10327/#post-139101

D-11 looks like it has more hydroquinone, so I guess it has even higher contrast.

 

[Lachlan Young]

Interesting, looks like it's not that far off D-72 1:2 which is what a lot of people have used. https://www.photrio.com/forum/threads/kodak-d-11-developer.10327/#post-139101

D-11 looks like it has more hydroquinone, so I guess it has even higher contrast.

You really should be using D-72 at 1+1 or undiluted, if Ilford's comments on using Bromophen for reversal FD are any guide.

Also, do check the sulphite levels in D-11 and D-72.