Can Kodak D76 be substituted for D94a by adding sodium thiosulphate?

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mr.datsun

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mrred. I'm excited by what I saw in your dektol processed slides. I will certainly investigate it as an option and the description of your process on the blog should be a great help to anyone who considers that route...
 

Photo Engineer

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In my previous post D75 should read D76.

Now, as for Dektol. It is used as a film developer when one is not overly concerned with grain. This mainly applies to processing film negatives. And, this use started with the newspaper industry when they found that Dektol with Super XX film using a 1:3 dilution for 3' or a 1:7 dilution for 7' gave negatives that could be printed in newspapers with good detail even though the original was rather poor. The printing process kind of decreased grain and de-emphasized sharpness.

So, amateurs today, seeing that practice, latched on to it, as it is a quick and easy (dirty) way to use 1 developer to get a film negative and prints as well.

So, yes it can be done but the highest quality is not gained.

Now, for reversal the situation is different in that the final grain is determined by the second developer. Sharpness is divided up between the two developers and so it can be a wash here for Dektol as first developer.

I always say, "use what works for you". In this case, without a side by side comparison, Dektol appears to (and does) work but may not be the best solution.

David Vestal and Al Weber both teach this method in their workshops with the same cautionary notes that I have made here. I trust them both implicitly.

PE
 

Oxleyroad

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Mr Datsun,

I mix a varient of D94a. I mix in everything but for DTOD. I have not had any issues with my soup when processing Foma, Shanghai GP3, ORWO UN54 or Kodak Vision 2/3 all as B&W reversal. I have not used my D94a (-DTOD) to process 7266 yet.

I have since moved on to Kodak D19. It is much easier to tear open a premix packet of powder when being lazy.

Also could I suggest that you give the sodium thiosulphate a miss. I do, and again I have done so since finding I cannot spot a difference between a 1st developer with sodium thiosulphate and a 1st developer without it. If you try without sodium thiosulphate and are happy with the results then run with it, if not then don't.

I also stay away from Permanganate Bleach because I have not had good experiences with it. Maybe I was doing something wrong... Dichromate Bleach has become my bleach of choice and proven to be reliable with all films I have used to date.
 

henry finley

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Photo Engineer said:
Dektol is a paper developer which has no concern for image quality. D75 and other film developers are designed for film quality Oh dear, I guess you younger guys do not distinguish between film and paper developers.

PE
Click to expand...

"You younger guys"? In your photo you look like some young professional with 10 years of post-graduate study, and the sharpest tack in the company. A real kick-ass professional. One of those that wakes up Kodak and goes to bed Kodak. That's the impression your photo depicts. When you talk, I'm listening to the gospel on the matter. These are my impressions. Hearing "you younger guys" from the profile photo does not register. Your photo gives the impression of being one of "those younger guys", and the sharpest one on the Kodak Park property.
 
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Photo Engineer

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Hennry;

I have been in the field of photography for over 60 years. That photo was my retirement photo from EK in 1997. I do not take a photo of me every year or so to update it, but the DVDs show mi in 1998, or 11 years later. Howzzat?

So Since I started photography at 8, and color at 12, you probably are an older guy!!! I was probably taking air to air photos in SEA when you were crapping in diapers. Anyhow, if I was wrong, apologies. If you wish to correct me, please do so. So, at the time of that photo I had had over 30 years experience. How about you?

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henry finley

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On my screen your photo is probably 1 inch at most, and you look like a young professional. to me. So now you're 60 years even smarter, as I now know. Now that just makes me respect your words more, sir. I'm 56. I'm just a printing-press operator-turned printshop owner. Nowhere near your Rochester professionalism and knowledge. You once told me one I needed to pipe down and open my ears a little. I take that as sage advice. Thank you for sharing your knowledge here, sir.
 

henry finley

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BTW I was 9 when I FINALLY got my Instamatic 104 for Christmas 1965. If anybody remembers the Dick van Dyke commercials on Bonanza, or Jackie Gleason, or Ed Sullivan--I can't remember.
 

MattKing

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henry finley said:
BTW I was 9 when I FINALLY got my Instamatic 104 for Christmas 1965. If anybody remembers the Dick van Dyke commercials on Bonanza, or Jackie Gleason, or Ed Sullivan--I can't remember.
Click to expand...

Beat you by a year henry - a Brownie Starmatic for my 8th birthday in 1964.

I expect my Dad used his Kodak employee discount .

The 11th birthday was better though -the Kodak camera shown in the attached plus a developing kit:
 

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henry finley

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Lucky dog. I had to "borrow" my grandfather's Ansco Memar all the way till Christmas 1972 when I got that Mamiya/Sekor 1000 DTL, and finally had a real camera of my own.
 
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mr.datsun

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Oxleyroad – thanks for the D19 advice. I may try it if I decide PQ isn't right when I start on the Super 8. I'm interested in your note about sodium thiosulphate – I added a similar amount to that suggested by the Ilford Reversal sheet. It wiped out the image by about 80%. So I rediced to 0.5g in 330ml and this improved but the image density was overall reduced by about 15%. Still thinking about that and went back to retest my original 1st/2nd times and mixes to check they were working correctly.
 

Ian Grant

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D72 (Dektol) can be used as well, it's generally not realised (or remembered) that it is in fact a Film developer with Universal properties, it gives quite high contrasts. At one time Kodak marketed D72/Dektol as a Film developer then also as a paper developer in the US but it was a few decades before Kodak Ltd in the UK began selling it as a paper developer in place of D163.



From Kodak Ltd, Kodak Chemicals and Formulae, 1949, US Eastman Kodak publications (same era) recommend it as a film & plate developer and also as a print developer.

Ian
 
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nworth

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Wrong! DTOD is HOCH2CH2-S-CH2CH2-S-CH2CH2OH (1,2-di(2-hydroxyethylthio)ethane). It was substituted for 9.1 ml of sodium thiocyanate (51% solution) (not thiosulfate) to turn D-94 into D-94A.

D-94 is very different from D-76. D-76 does not have the energy to make a good reversal first developer, although variants of it have been used for some special purposes. Reversal first developers are normally high contrast negative developers, like D-19, with some thiocyanate added as a silver solvent to keep the highlights clear. D-67 is another popular first developer. It is simply D-19 with 2 g per liter of potassiun thiocyanate added. Dektol is fairly close (but not the same) as D-19; diluting it 2+3 and adding thiocyanate may (but only may) work decently.
 

mrred

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What nworth said. The recipe ilford presented was tailored for ilford's offerings. This is why I make a hypo solution an add it at developing time, if required at all. You need to build up enough developed silver first, and that will be different with each type of film. I do not put any pre-mixed in the developer for that reason. Just have a look at the tables I posted on my blog.

I shoot a bunch of frames ranging from 25 to 1600 iso in 1 stop increments with a card indicating what iso I am shooting. When I look at the developed strip, it allows me to guess how much more (or less) hypo to add. You need to take a more systematic approach to nail it down.
 

Vaughn

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Ian Grant said:
D72 (Dektol) can be used as well, it's generally not realised (or remembered) that it is in fact a Film developer with Universal properties, it gives quite high contrasts.
Click to expand...

I have been using Dektol to develop sheet film (for carbon printing) ever since I accidentally grabbed a bottle of Dektol instead of the D-76. I was going to use the D-76 because I ran out of the Ilford PQ Universal Developer.

The neg came out fine...so did the print:
 

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mr.datsun

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Mr Red. Thanks for the response and I have been studying your blog and wanted to ask you some questions. I worked out that the reduced volume of hypo (0.5g in 330ml) I was using in my 2nd hypo test was in the same ballpark as yours when I tried it. It was hard to measure 0.5g and I thought that next time I would use your hypo solution method so I could work with smaller increments more like 0.1g per 330ml. Obviously my film is not one you have tried so I will need to work out the right amount of hypo for the Tri-X – I hadn't thought it would be such a drastic deviation. Clearly I need to do a lot more tests and then I really ought to be testing on Super 8. I think that the slightly opaque base of the Tri-X is making it hard to evaluate at the moment.

Question1. 'You need to build up enough developed silver first'. You mean getting the first development time and dilution correct before hypo trials?

Question2. Also, how did you decide whether to use Dektol at 1+1 or 1+2 for each type of film?
 
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mr.datsun

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nworth. Thank-you. I understand the difference between D-94 and D94a. I was only saying that I thought that in place of the DTOD in D94a which is its hypo we could use instead, sodium thiosulfate which is also a hypo when tyring out another substitute developer. I didn't mean to suggest that I thought D94 contained sodium thiosulfate itself.

Anyway, Mr Red's Dektol work suggests that it's a good developer for reversal.

Would you know whether D-19 or Dektol are higher contrast than the PQ Universal that I'm currently testing with?
 
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mr.datsun

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And another thing. Kodak now have a Dektol in liquid. POLYMAX Paper Developer 500ml Liquid.

'Neutral to cold working paper developer, recommended by Kodak for virtually everything. Liquid is the best value, diluting 1+9. Powder packings dilute 1+2. Kodak Polymax is a re-named Dektol in a small packaging.'

I may find this easier. But I'm unclear, what is the equivalent dilution to get the same 1+1 or 1+2 strengths that you would use when dektol is mixed from powder?

EDIT:

http://www.kodak.com/global/en/professional/support/techPubs/e103cp/e103cp.pdf

So I'm guessing that when the Kodak sheets says 1:2 for Dektol stock from powder they really mean 1+2 and when they say 1:9 for the dektol liquid they really mean 1+9.

Therefore 1+2 stock from powder is equivalent to 1+9 from liquid and so that 1+1 is equivalent to 2+9 of the liquid form.
 
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Photo Engineer

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My last post sparked some discussion of old age. Sorry. And, the date for the DVDs should be 2008 not 1998. Sorry. So, I am now older and wiser. I hope.

Anyhow, Kodak once made a Universal MQ developer for film and paper that cane packed alone or in Tri Chem Packs. They also had a liquid called Versatol which could develop films or paper. This worked well when the films were 4x5, but as people moved to 35mm and the films became more sophisticated, these products were no longer recommended as universal.

All of the major film companies recommended different developers for film and paper, and different dilutions for the fixer to be used for them. This is to get the optimum image.

So, i suspect that when using 4x5 negs from Dektol, one will be quite happy as compared to the 35mm user who develops his film in Dektol.

In 1965, I was starting work at Kodak after leaving the USAF and getting my graduate degree. So, yes I am older than in the picture. I'll have to post a portrait or something I guess.

PE
 

henry finley

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I wonder what DVD's you're talking about. I guess it must be stuff I don't seem to have permission to see. And nothing wrong with the picture you have. It looks like a so called "yuppie" of the toughest kind. Kind of what I would have always pictured a Kodak engineer/technician to look like. Somebody who knows the nuts and bolts of it top to bottom. Reminds me of the Kodak paper swatch books at the camera store in the 1970's. I tried but was never able to get the clarity and the highlight-to-shadow detail those swatch book photos had.
 

mrred

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mr.datsun said:
Question1. 'You need to build up enough developed silver first'. You mean getting the first development time and dilution correct before hypo trials?

Question2. Also, how did you decide whether to use Dektol at 1+1 or 1+2 for each type of film?
Click to expand...

1: I take an unexploded strip of film and develop and fix it. You are looking to only get a minimal amount of base fog. That will indicate black limit of the developer. A little fog is okay,as the clear will take care of it. Too much and your image will get too thin. This test is handy to figure out solutions and development times.

2: see above.

The solvent (hypo) does not really just take care of the highlights, but think of it as applying a curve to your image. The above to be applying the lower curve. You will know what to adjust by what you see.

Some films work better than others. Foma 100 is about perfect, and no hypo was required with dektol. Plusx was my favorite before that. Neopan 400 is wonderful, but across 100 is disappointing. I have never liked the results enough from tmy to keep using it.
 

mrred

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You don't explode film. my playbook strikes again!
 

Tofek

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Mrred, I don't get it : you develop and fix a strip of unexposed film. Then why develop it when there will be nothing to develop if it's unexposed, and you'll end up with a blank strip ? How do you recognize the correct first development time from this ?
 

mrred

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What you are looking for is fog. That's the point when the developer shows something from nothing, or in DigitalIze - noise. Look at any of your negitives, they all have a varying degree of it.

To demonstrate, take some unexploded ( ) film and put it in your developing can. Use PQ or Dektol 1:1 (or the strongest of whatever you have) and do a time of 20 mins or so. Fix it and have a look. That would be fog.
 
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mr.datsun

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Tofek. My take on it is, that with Mr. Red's method, you do a series of developer time tests. Say 4, 6, 8, 10, 12... (or smaller increments) until you get fogging on the base. Then with the last one that shows no fog or just a touch of fog – that's the max amount of silver you can ever get out of the film with your developer before you've begun to lose the shadow detail and contrast. Because even with blank film the developer will eventually start working on unexposed/unexploded halides – to preserve the clear base you have to stop development at that point.

I've been thinking about this and decided that i could take 6 or so small strips of tri-x and then put each one in turn into the dev, time it , stop it, fix it and then compare them at the end. I thought I could try and mark the strips with numbered notches. Use one mix of dev for the whole test and it's done - ideal development time is sorted for good. (Then perhaps do it for a other dilutions for completeness or if the contrast needs adjusting in the final exposed image tests.)

It separates out the question of ideal development time from the one of exposure.
 
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