Kodak D-76 Developer & Fixer: Did I make a mistake?

This week I prepared batches of Kodak D-76 and Kodak fixer for the first time (first time preparing any developer or fixer) using the instructions on the packet. I thought it all went well but I think now that I may have made a mistake. In both cases, I mixed the bag of chemicals with 3 litres of water at the specified temperatures until dissolved. I then added an additional 800ml of water to the mixture. I realise now, or I think now, that I should have added enough additional water to make up 3.8 litres in the mixture.

 

Have I made a big mistake or is it not so critical? I plan to dilute the developer so perhaps I can make adjustments there, but I think the fixer is to be used straight.

 

Please let me know - thanks!

It can be critical, but not this time.

 

Sometimes the developer (or any solution) has a saturation point where no more chemicals will be absorbed by the water. But the resolution is simply to add the required amount of water and keep mixing until all is absorbed.

 

It looks like you caught your error at the right time and all is good.

 

Happy developing!

Thanks Peter, but I added an additional 800ml of water to the 3L of water + chemicals. I did this for both the developer and for the fixer. Won't the solutions be too dilute?

Smile, all will turn out OK. Just make sure you do not mix the two solutions up in any manner. Aloha, Bill

Making big volumes of solutions is a big part of my day job.

 

I've found that D76 can be a bit stubborn. I use to mix it directly in a Datatainer bottle. I would dump the packet in, then fill it with hot water while stopping to shake every little bit. Once I've filled to the prescribed point(1 gallon for the packets distributed in the US, ~3.8L) I shake for a while and then usually let it stand overnight while checking on it occasionally.

 

I got tired of doing that, so I now generally mix it up at work. I use a 6L Erlenmeyer flask and leave it overnight on low heat with vigorous stirring(magnetic stirrer).

A typical beginners mistake. The powders will also take a certain volume hence adding water till a total volume of 3,8 Ltrs. Indeed you dilute a little bit too much.

But this mistake is less then 5% in the total process of film developing and you can only find it back in reprocibility when having a densitometer. So do not worry just use it as described in the instruction manual.

A typical beginners mistake. The powders will also take a certain volume hence adding water till a total volume of 3,8 Ltrs. Indeed you dilute a little bit too much.

But this mistake is less then 5% in the total process of film developing and you can only find it back in reprocibility when having a densitometer. So do not worry just use it as described in the instruction manual.

 

Yes, this is a rule with making ANY solution. At work, I make some where the volume of the solute is insignificant, and in others it's quite significant.

 

With D76, Dektol, and thiosulfate solutions at photographic concentrations this is very true.

 

If you read most "recipes" the last step is usually to add water(or whatever solvent) to a t.v. of whatever.

Thanks Peter, but I added an additional 800ml of water to the 3L of water + chemicals. I did this for both the developer and for the fixer. Won't the solutions be too dilute?

I missed that point... :(

The clue is in the words "water to make..... "

 

The additional volume of dry chemicals amounts to about 40ml in each litre. A 4% error in concentration. Just add a few extra seconds to the developing time - 2.4 seconds/minute of developing time to be exact. However a less-than-perfectly accurate thermometer would probably give you a greater error than your dilution mistake.

 

The effect on fixing time will only be apparent when the fixer is nearly exhausted. Just discard it a roll early, or extend the fixing time by 5% to be on the safe side.

The clue is in the words "water to make..... "

 

And that phrase is ONLY applicable when everything is dissolved, although the error is quite small if the majority of it has dissolved.

 

There again, that's why I like mixing it overnight with a magnetic stirrer...if it weren't for the fact that I have such ready access to them at work I'd virtually consider one a necessity in the darkroom.

The fixer was a 700g packet whereas the developer was 415g, both to make up 3.8L. What those weights convert to in volume once in solution, i don't know. Rodeo_joe, you mentioned 40ml, is that for the developer? I certainly noticed a diference in volume between the the developer and fixer. I filled up 3 "1 litre" bottles to the brim (so more that one litre in each bottle). The left over liquid for each, I poured into a 500ml bottle. The developer is about 2/3 full whereas the fixer is 3/4 or a bit more.

The error in the fixer will be greater, since it has a higher concentration of sodium or ammonium thiosulphate than that of sodium sulphite in D-76. Sodium sulphite makes up the bulk of D-76's formula, and thiosulphate forms the bulk of any fixer.

 

Even if the fixer is diluted by 10% too much - which I doubt - it'll make almost no difference to its fixing ability. Fixing is done to completion, and the time given in the instructions is very generous for a fresh solution.

 

As the fixer is used, its power decreases and the fixing time becomes longer. No big deal, since the recommended capacity (rolls of film per litre) is stated on the safe side.

 

As I said, you can either throw the fixer away a roll before its recommended capacity, or extend the fixing time a bit longer.

 

Another option would be to split the fixer into two batches and follow the procedure in this thread.

Thanks a lot rodeo joe, I'll read the link later tomorrow

Well, I developed my first roll of film. The chemical bit went well, however I botched the spooling of the film onto the stainless steel reel. Despite practising 20 or more times with an exposed roll, the film got stuck together in places and crumpled, and well, you know how it turned out. Some salvageable images perhaps. I'll take the negs in to be scanned professionally....

 

Hopefully I'll get it right the next time! Thanks for your help everyone!

My own experience with loading the reel is that it is not like riding a bicycle, you have to learn it all over again every time.

 

Look upon it a a sort of tax on the one hand, and a way to get more pictures for the Abstract forum, on the other;)

A magnetic stirrer doesn't make much sense for most people but, like a remote control for the TV, once you have one it's hard to imagine going back. I mix my developers from scratch and it makes the job a breeze. I would worry a bit about running it longer than necessary to get the chemicals dissolved, lest more oxidation occur than necessary.

I would worry a bit about running it longer than necessary to get the chemicals dissolved, lest more oxidation occur than necessary.

 

Once again...the advantages of working in a lab...

 

When I do this at work and stir overnight, I seal the flask and keep it purged with a nitrogen balloon.

As above, the fixer will be fine. Increase the fix time by one minute, and decrease the capacity by one roll per liter.

 

For D-76, if you use 1:1, you can correct the dilution when you dilute it.

 

If you use it full strength, increase the development time proportionally to the increased dilution.

 

Don't use it for case when you are trying for exact exposure, or for your best friend's wedding.

Most likely you will easily be within the exposure latitude for the decreased strength, even if you

don't increase the time proportionally.

 

But yes, it is traditionally in all of chemistry to do it this way.

"Most likely you will easily be within the exposure latitude for the decreased strength..."

 

- Developing has nothing to do with film speed or exposure. Let's knock that idea out of the park straight away.

 

Film speed is pretty much set in stone during manufacture, and developing time, or dilution, varies it very little. So-called 'pushing' or 'pulling' the developer can only vary contrast, not exposure.

 

The effects of under/over exposure and development are quite separate and different.

 

WRT magnetic stirring: Never found any need with common developer or fixer formulations. Any stubborn 'bits' from pre-packed developers are probably impurities or precipitated water hardness anyway, and you don't really want those stuck back in solution.

 

Now Glycin and PPD, they're real buggers to get fully dissolved!

Edited April 16, 2018 by rodeo_joe|1

I'll post here the best of the roll and the best (most interesting) of the "abstracts", most of which are unusable. If anyone can recommend a good video on how to load a stainless steel spool, please let me know! The first photo is of a sculpture called Pombal and is home to hundreds if not thousands of pigeons. The second is of Brazil's congress buildings, situated just a couple of hundred metres away from the sculpture:

 

 

Hey, you got some useable images from your first roll of film. Be proud!

 

With the reels, practice with your eyes closed on some junk film, and then practice some more. You’ll get it in no time!

Can I politely ask why not just use HC-110, 1:31 (dilution B) as a single shot and not have to deal with these issues at all? Or ID-11?

Yes, they are different developers, but produce very similiar results. HC-110 produces slightly sharper grain to my eyes while D-76 has a bit better solvent effect. Otherwise, the average joe messing with B&W isn't going to see a difference, and a bottle of HC-110 syrup will last longer than you will keep interest in this hobby. Mix half an ounce of HC-110 with 16oz water - done. No need for working dilutions or anything else. It sits on the shelf until you need it.

I keep reef tanks, and mixing up salt mixes brings back the same annoyances with D-76 and Dektol powder. Dektol was tougher to replace as a robust paper developer, but neutol in liquid form complimented Kodafix nicely. No powders...no worrying about mixing powders, and they can sit on the shelf until needed.

"Most likely you will easily be within the exposure latitude for the decreased strength..."

 

- Developing has nothing to do with film speed or exposure. Let's knock that idea out of the park straight away.

 

Film speed is pretty much set in stone during manufacture, and developing time, or dilution, varies it very little. So-called 'pushing' or 'pulling' the developer can only vary contrast, not exposure.

 

(snip)

 

I mostly agree, but not completely.

 

For one, film speed is mostly on the bottom end of the curve, and yes that doesn't change much with development increase.

 

But note that increased development can move the highlights out past the upper end, which goes along with the increased contrast.

 

But in this case, we are talking about maybe a 5% change in development, due to slightly more dilution, not the change needed to push two or three stops.

 

Also, more dilution means underdevelopment, or pull processing, but I am assuming no increase in exposure.

 

The bottom of the curve does change with development, just not all that much. One could be unlucky, if one needed shadow detail, and it was lost due to underdevelopment.

 

It is usual to rate films on exposure latitude, but not on development latitude.

 

Overdevelopment doesn't increase shadow detail much, but underdevelopment can easily lose it.