does d76 get more grainy with age?greenspun.com : LUSENET : B&W Photo - Film & Processing : One Thread
i've been using the same batch of (1 gal) d76 (used as one shot @ 1:1) for about 4 months now and recently my negs (plus-x and tri-x) seem to be getting more grainy, i'm wondering if it's due to aging of the developer? i keep it in a plastic jug and squeeze out as much air as possible but it's gotten so low as to not be able to keep all the air out....... the only other thing that has changed is my development temp has gone up, i used to do everything at 20 oC but with the summer i can only get down to about 22-23 oC, i have shortened my development times accordingly (i think)
thanks for your replies! joe
-- Joe Holcombe (email@example.com), June 07, 2001
I doubt 4 month old developer is responsible for increased grain; at least that's not my experience. The increased temperature, or a sudden change in temperature from dev/stop/fix would more likely be the culprit. Processing in a water bath, with ice cubes can keep your temperatures more stable.
-- Pete Caluori (firstname.lastname@example.org), June 07, 2001.
Kodak D-76 is notorious for gaining activity as it ages. The pH gradually declines (I think) with time and that activates the hydroquinone (which is normally inactive). See Anchell's The Film Development Cookbook for more.
What is happening, as a result: your film is being overdeveloped. This increases grain.
The solution: change developers, or use fresher D76.
I used to use Ilford ID-11 because you could buy 600 mL packages. I don't think you can any longer, but they still have 1 L packages. ID- 11 is functionally identical to D-76, and, in fact, some believe more chemically pure to the original D-76 than the current Kodak product.
-- Jim MacKenzie (email@example.com), June 08, 2001.
As mentioned above, the pH of D-76 changes and activates the high contrast part of the formula: hydroquinone. More contrast can also mean more graininess. You're best off making a fresh batch. Or get The Film Developing Cookbook and mix up D-76H, which omits the hydroquinone altogether. It looks the same as D-76, but avoids the consistency problems you're experiencing.
-- Brian Hinther (firstname.lastname@example.org), June 09, 2001.
> Kodak D-76 is notorious for gaining activity
I wonder how valid that is for packaged D-76; it contains a buffer to prevent that problem, and is said to be actually D-76d, which is consistent with the info in the MSDS.
As for increased graininess, higher development temperatures yield increased graininess (Henry, _Control in Black and White Photography_) with the "best" temperature being 68F-72F.
While I doubt developer age is the problem, four months is a fairly long time to have a jug of D-76 kicking around. I'd suggest simply mixing smaller quantities. If the reason for mixing a gallon is cost of the quart size, you might consider mixing your own developers. A relatively inexpensive balance scale makes it easy; otherwise conversion tables to use tablespoon'n'teaspoon methods can be found.
The simplest is D-23.
Water 750ml 125F
Sodium sulfite 100g
Water to make 1.0L
Use straight or diluted up to 1:3. Developing times will be longer than D-76 but neg characteristics will be pretty much the same. Contrary to common opinion, D-23 isn't a "soft-working" developer; it can yield the same curve shape and CI as D-76 if the development time is long enough. I believe most who consider D-23 to be a low contrast developer simply aren't developing long enough.
A D-76 variant, D-76H, is easy to make. It works the same as D-76 but hydroquinone is eliminated to avoid any concerns about the pH increase with age activating hydroquinone.
Water 750ml 125F
Sodium sulfite 100g
Borax (20 Mule Team) 2g
Water to make 1.0L
-- John Hicks (email@example.com), June 09, 2001.
thanks for the information all, i was hoping it had more to do with developer age than temperature but it looks like that's not so, i guess it will just take longer to develop film in the summer as now i have to mess with ice and such..... oh well
-- Joe Holcombe (firstname.lastname@example.org), June 11, 2001.
> mess with ice
It's really not that bad. Pour all your chemicals into wide-mouth containers. Put some ice cubes in a plastic sandwich bag. Dunk the bag into the developer and monitor its temperature until the developer is down to around whatever your target temperature is. Then do the same with the stop, fix etc in sequence, letting each be a couple degrees higher so you don't end up making a huge jump from a cold solution to the much warmer wash water.
Rinse off the thermometer and recheck the developer; it's probably a degree or so warmer by now, so develop at that temperature.
No need to go all the way to 68F; anything below 74F-75F is fine.
Look in the Kodak tech sheets or in the Darkroom Dataguide for time/temperature compensation info to be sure you're reducing the development time appropriately. There's a one-size-fits-all formula for approximating it (perhaps someone could post it) that'll be close enough.
-- John Hicks (email@example.com), June 12, 2001.
From Richard Knoppow over in USENET:
D-76 mixed according to the original formula will increase in activity over a period of weeks. This is full strength developer. The rise in activity is due to a complex interaction between the sulfite and hydroquinone. Mike Gudzinowicz once posted a quite complete explanation of the chemical process. It may be available in the data base currently on Deja.com. In any case its worth a name search there.
Packaged D-76 is a modified formula using a buffer. It does not suffer from the rise in pH and activity of the original formula. Diluted D-76 has a short life because there is not enough sulfite to prevent fairly rapid oxidation. At 1:1 or greater its strictly a one-shot developer. For those who mix their own the difference in the formulas is that the original D-76 contains 2.0 grams/liter of Borax. In the buffered variety this is replaced by 8.0 grams of borax/liter plus 8.0 grams/liter of boric acid. The initial activity of the two is the same but the buffered version maintains that activity for very long periods. The original version starts to increase activity immediately.
The original research paper describing the effect and cure shows that after several weeks the time required for a give contrast is nearly halved with the unbuffered form but remains the same for the buffered type. Mixed D-76 stock from the packaged powder should have a life of a few months in a sealed bottle. Kodak gives two months but that is quite pessimistic. D-76 should be nearly clear to very slightly straw colored. A darker brown indicates excessive oxidation and discolored solutions should be discarded.
-- Tim Brown (firstname.lastname@example.org), June 13, 2001.
I use 4 small reusable drink bottles. They are a quart in size (or litre). They have wide mouths, screw-on lids, and a snap cover over the spout. I premeasure my chems (dev, stop, fix and HCA) so when it comes time to add them, I just add the entire container. Having them premeasured also allows me to play with temperatures more easily (less to bring up or down in temp). I have a small washtub that I can fill with the proper temperature water (for maintaining or adjusting temps). I drop in my small bottles and allow temps to adjust. Every now and then I will pick up a bottle, swirl the chem inside and measure the temp. It might take a little bit for temps to come in. In the meantime, I finish up my other prep work (dig out my timer, prep the darkroom bag, etc). When temps come in, it's developing time!
Don't be in such a hurry to get things done. Take your time and you can better guarantee your resultes.
-- Johnny Motown (email@example.com), June 13, 2001.