View Full Version : Factors that affect the developing process

14-Nov-2009, 13:17
Hi everyone,

im trying to get my head round to a few factors that affect the developing process. I know that they have to be a certain way but i dont actually know why.

can someone clarify:

- the significance of having the right temp (developer and room) & what will happen if it is too hot/cold?

- what will happen if you reduce or increase the time in developer ( more than the needed amount)

- does the developer age? if so how does it affect the process? will it ruin the print?

- how does light affect the developing? i mean there a red light in there but its safe right, ive had no problems so far.

can you affect the contrast of an otherwise flat image while developing ( by keeping it in longer in the bath) or should u sort that out on the enlarger first by burning/dodging?

thanx in advance

14-Nov-2009, 14:51

They mostly have to be a certain way to produce consistency. You can change them if you want, but do it methodically and don't let much change at once. Unless you are majoring in chemistry, you'll probably never know the why's in much more than a general sense, and that's OK.

1. The chemicals work differently at different temperatures. Typically things happen faster at warm temps and slower at cool temps.

2. For film, you will likely increase contrast as if pushing the film. For paper, not too much, just thickens the shadows a bit.

3. Developer reacts with the air in the bottle, contaminants, and other chemical instabilties. For film, failing developer will make your negatives "weak" or thinner than you want. For paper, it will get looking nasty and not let you make pure blacks.

4. depends on the film. I use no light when unloading and processing film. Paper is generally safe under a safelight for more time than it reasonably takes to expose and process it.

5. I use variable contrast paper (and a color head) to adjust contrast at the enlarger.

14-Nov-2009, 16:10
It’s important to treat any developer carefully – not only during the development process. Its “keeping properties” vary with the type you use, the way you use it, and the conditions under which you store it.

A quick example: Kodak says you can store D-76 in full-strength stock solution for 6 months in a closed, full container – but recommends that you not store 1:1 working solution at all!

What’s more, they say 1:1 working solution (w/o use) is good in a tray for 24 hours (which makes one curious why they don’t recommend storage in a closed container) – but they don’t recommend that you "keep" it in a tank.

So many “rules” for just one developer! But don’t be a slave to them.

Best is to keep such guidelines alongside notes about the consequences of your own darkroom habits, and what you learn from trusted darkroom veterans.

Eventually, sensible use of developers (and other chemicals) becomes second nature.

Bjorn Nilsson
14-Nov-2009, 17:40
There are so many things which varies in the process from loading the film and setting up the camera up to presenting the final print. Many of those deals with assessment and compensation in one way or the other.
Taking a picture needs the artist in you.
Printing the picture needs that very same artist to make the picture you saw when shooting come alive again.
But the "middle stage" where you process the film is one stage where you should'nt improvise in any way. Film processing should be predictable, as it's only an intermediate stage between the shooting and the printing stage. This is why I process (most of) my film in a Jobo processor nowadays. Not because I'm a perfectionist, cause I'm not. I just don't like the quite monotonous work of developing film and the Jobo does processing in exactly the same manner every time, without getting too bored with it. I still have to be around to change the chemicals etc on time, but that's it.

As I pointed out above, you can compensate a bit more when printing. Apart from using decently fresh developer, you can get away with some variations in temperature etc.
With prints you usually develop to completion, i.e. at least e.g. 2 minutes or until just about nothing more happens. So if there is a lot of development action still happening after 2 minutes, let that happen and observe it. When nothing more happens, after say 3 minutes, adjust your enlarging time accordingly and always develop for 3 minutes. Now, if you print on a hot day and the temperature is say 25 degC (instead of 20), those 3 minutes will probably be more like 2 minutes. But that only takes you 2 minutes to check with a test strip.

Apart from this there are many many things to learn about printing. As you posted your good questions in a very serious forum, I recon you are serious about your intended results too. There are some very good books on the subject by e.g. Tim Rudman and many others, which will serve you well.


16-Nov-2009, 11:41
thank you all for you replies. I am truly learning so much already!

-what affects the temperature of the developer? is it the heat it produces when developing? I always have to adjust the temp by pouring in some water to get the temp back to 20 degrees C.

-If your choice of film, along with the lighting conditions, were to indicate a correct exposure of half a second @ f2.8 (wide open), what are the implications that would need to be considered and could they be got round in any way?

thanx in advance ( also thanx for the recommendation of books!)

J D Clark
16-Nov-2009, 15:07
As you mentioned, chemicals work differently at different temperatures, more slowly at lower temps, and more quickly at higher temperatures. The temperature of your solution is affected primarily by four things: 1.) the temperature of the bath around your tray (if you're using a temperature bath around the tray; 2.) the ambient air temperature; 3.) evaporative cooling; and 4.) and the amount of time your hands are in the solution (consider them 98 degree F heaters).

I use a slosher tray, so my hands in the solution do not heat the developer, although, when I developed films by the "card shuffling" method, I *did* observe the temperature increase by several degrees during the 6-7 minutes of developing.

The reaction of the film in the developer is not very exothermic, so there is no appreciable heating as a result of the reaction.

The three primary factors that effect the amount of the developing reaction is the temperature, the time, and the concentration. So, if you add water to change the temperature, you're also affecting the concentration -- greater dilution will cause the reaction to proceed slower. So, if you add water, you're going to end up with an inconsistent result. What I do, and I recommend, is put ice in a zip-lock plastic bag, and put it in the developer just long enough to get the temperature you want.

John Clark

Gem Singer
16-Nov-2009, 16:03
So far, nobody has mentioned the importance of agitation of the film while it is immersed in the developer.

The type of agitation (rotary, dip-and dunk, etc.) and the amount of agitation (continuous, intermittent, stand, etc.) effect the final outcome.

To put it simply, the more the agitation while in the developer, the greater the density it produces in the negative during the development procedure.

The method and degree of agitation also effects the evenness of development and the grain pattern in the negative.