D76 mixed from scratch - expired powders?
How can be seen if metol or hydroquinone powders are expired?
My metol is pale grey and my hydroquinone is light ivory...
If I mix d76 from them I get consistently thin negatives to my eyes...
Since I don't have a densitometer I don't know how can I perform a proper developer activity test...
Last edited by Alessandro Serrao; 05-23-2009 at 01:08 AM. Click to view previous post history.
I'm no chemistry expert, but if your negs are looking thin, your hydroquinone might well be kaput. Either way, it's easier to buy some fresh chemistry than put up with consistently thin negs. A bloke from Rayco (chemical suppliers in the UK - now sadly gone) once told me, if you're in any doubt about metol, just use it for paper developers. The logic being, you can always make a new print. You can't - obviously - reprocess your films.
Norman is an island.Time and tide wait for Norman.
I'm also making a simple consideration: apart from being able to make some esoteric developers (that I don't anyway) I don't think mixing from scratch would be much more cheaper than buying commercial products (fixer is the typical example). I mean, I only use D76 and XTOL and buying always fresh chemistry avoids problems like I'm having and ensures repeatibility and consistency.
Originally Posted by Blighty
I process maybe 2 rolls per month if I'm lucky, so...
I have kept hydro for 30 years and it works fine.
Metal needs to be white. I get a pound at a time and put it into small 4 oz bottles, about 8 of them. Tape seal the lids and it lasts forever.
File a plastic spoon down so it fits inside the small bottle to remove material.
It last forever that way.
MMM waterproof tape, clear.
So if metol is light, pale gray can it be the culprit?
Originally Posted by Ronald Moravec
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I would say yes. You can get some new premixed D76 and run a test roll thru it. That will answer your question about dev strength.
Originally Posted by Alessandro Serrao
If you're only doing 2 rolls/month, you may want to look into HC-110 or Ilfotec HC. You can use a syinge (available at druggist) to measure small quantities and the syrup in the bottle lasts forever. HC-110 is often called a "liquid D-76".
Mix 2 grams Metol in 100 ml warm water. Is the solution clear? Is the solution colored? Either way, mix 5 grams hydroquinone together with 100 grams sodium sulfite in 500 ml warm water. Add this solution to the first. Now add the 2 grams borax and the rest of the sulfite and add water to make 1 liter. Now test it with film.
You will note that the metol is to be dissolved first without any sulfite. The custom among some of dissolving the Metol with a small amount of sulfite to protect it is not good. Metol is acidic and keeps itself beelow its minimum pH of activity while the solution is acidic. Adding sulfite next will make the solution basic and will convert all oxidized Metol to an inactive form. OTH, Hydroquinone in sulfite solution will restore oxidized Metol (as will ascorbate solution.) If you are going to throw away the Metol anyway, you may as well try this ploy.
use Gainers method of mixing. I have used metol that is a rather dark tan and as long as the resulting developer does not stink it has worked well. I have never known hydroquinone to go bad. My current stock is probably 30 years old and is still just off-white, light and fluffy.
Thin negatives are not always a result of chemistry. Have you tested to see what your exposure index should be or have you accepted what the manufacturer said? Although I dislike bracketing, try it on the next roll film. Then increase the development time about 25 to 30%. This will give you an indication of a more correct exposure index, and also some indication of whether or not your development time is too short.
[FONT=Comic Sans MS]Films NOT Dead - Just getting fixed![/FONT]
I just went and had a look at my Metol, it is a light grey.
I opened this 2,500gm white plastic jar in 1992, I'm about half way through at the moment.
I mixed some D76 up two Fridays ago.
Two Saturdays ago I developed 4 rolls of 135 film, beautiful negatives.
Today Sunday, 8 days later, I have just come in from the darkroom after developing another 4 rolls of film from the same batch, beautiful negatives.
I have heard about Metol going grey and off, so far I haven't had any problems.
It is just stored in it's original container, it sits on the shelf and has gone through 17 winters and summers with a temperature range of 0.1║ C through to a high of 47║ C last summer.
That method, BTW, is not mine, as I said in another post. I found it in the chapter on photography in "The Principles of Optics", 1931, by Hardy and Perrin. It makes good sense in view of other information about the reactions between Metol and ascorbate, Metol and sulfite, and Metol and hydroquinone without sulfite to be found in "The Theory of the Photographic Process", 3rd edition.
Originally Posted by Jim Noel