variables in film development

[ulrich.von.lich]

I have developed several rolls of films with the same routine and got consistent results. Now I'd like to play around with one of the variables.

Here's what I have written down:

Higher dilution = more grain, less contrast, more sharpness
More agitation = more contrast/density
Less developing time = less contrast/density
More temperature = more contrast, more grain

Are they correct or complete?

I think I will start with the dilution first.

One thing I have always wanted to ask: apart from Rodinal, why can't I dilute infinitely other developers to achieve ultimate low contrast and sharpness? Say, what would happen if I dilute the DDX to 1:50?

I have also noticed that low dilution is often recommended for pushing films. If time is not an issue, wouldn't it be better to use a higher dilution to reduce the contrast, since pushed films are often already too contrasty.

Thanks.

Cheers,
Tony

 

[Roger Hicks]

I have developed several rolls of films with the same routine and got consistent results. Now I'd like to play around with one of the variables.

Here's what I have written down:

Higher dilution = more grain, less contrast, more sharpness
More agitation = more contrast/density
Less developing time = less contrast/density
More temperature = more contrast, more grain

Are they correct or complete?

I think I will start with the dilution first.

One thing I have always wanted to ask: apart from Rodinal, why can't I dilute infinitely other developers to achieve ultimate low contrast and sharpness? Say, what would happen if I dilute the DDX to 1:50?

I have also noticed that low dilution is often recommended for pushing films. If time is not an issue, wouldn't it be better to use a higher dilution to reduce the contrast, since pushed films are often already too contrasty.

Thanks.

Cheers,
Tony

Dear Tony,

And don't forget changing developers, which is enormously important.

The decline in development is NOT linear, i.e. halving the concentration doesn't necessarily mean twice the dev time. Sooner or later there's not enough dev to do the job: it exhausts (or more likely oxidizes) before development is complete.

I'd really start with time, if I were you. What don't you like about your current negatives?

Cheers,

R.

 

[jbielikowski]

generally ok, but higher dilution= less grain. shorten time when you increase temp, other way you can under develop film. you cant dilute all developers cause it has to be certain amount of it in water to work, and rodinal is highly concentrated.

 

[ItsReallyDarren]

I'm curious about the effects of temperature on the development characteristics. I use higher temperatures to shorten the development time but haven't done it enough to observe the difference between the standard 20c.

I can say agitation has an effect on contrast. When I agitate more I get more contrast, less agitation gets me less contrast. It is subtle though depending on how much agitation.

 

[Freakscene]

it exhausts (or more likely oxidizes) before development is complete.

Generally this is the same thing, because development products also catalyse oxidation in the developer. The 'preservatives' in developers are antioxidants, which are reducing agents that accept electrons that can cause other compounds to oxidise. Antioxidants work by more readily accepting electrons than the substances you are trying to protect.

In practice, antioxidants are added to a developer to slow oxidation rather than to stop it, because a degree of inhibition of development in areas of intense developer activity (typically the densest part of a negative) is desirable. So, eventually the oxidants released by development overcome the antioxidants and oxidise the developing agents. In combination with consumption of the developing agents from developing latent image silver, this is when exhaustion occurs.

In comparison to these types of oxidation, oxidation caused by other compounds (dissolved oxygen and ions in the mixing water) is relatively small over a typical time taken to develop film. Developer stock solutions resist oxidation better because the concentration of preservative is higher (their ability to protect from oxidation is not linear) so a working strength solution of most developers will auto-oxidise fairly quickly.

Those who use long development times in (for example) dilute Rodinal should do some proper investigations; I suspect most are leaving their films in the developer a long time after the developer has stopped working, effectively decreasing the quality of their negatives by leaving them to soak in a highly alkaline solution (with associated over-swelling of the emulsion and increased grain) long after development has stopped.

Marty

 

[Roger Hicks]

Dear Marty,

Of course you are right. Sloppy thinking on my part. I was thinking of a friend who uses PMK in a CPE-2.

Cheers,

R.

 

[Freakscene]

Hi Roger,

An interesting point - it's more complicated than I wrote above, particularly with developers; other than largely conventional formulae. PMK has only 10g/L of bisulfite as an antioxidant and oxidises aerially faster than most developers. Using rotary development will speed oxidation up. PMK is one of those developers that probably does auto-oxidise fast enough for that process to contribute meaningfully to exhaustion, but that auto-oxidation occurs at the same time as oxidation from development by-products. I could do some experiments to work out the proportion of developer lost to each type of oxidation, but I have enough things to do that are meaningful to how I work without going down that road. I also should add that working solutions of PMK have a high concentration of developing agent, probably to counter losses to oxidation, and that dilution overall also changes the proportional oxidation of developers. It is also interesting in PMk and other staining developers that the development by-products are still active tanning and staining agents, increasing the complexity of what happens as development slows.

Thanks,

Marty

 

[Roger Hicks]

Dear Marty,

Precisely. As I say, I suspected oxidation in the strictest etymological sense, from atmospheric oxygen, from that set-up, and then extrapolated it, without really thinking, to things like weak Rodinal. This also led me to ignore the normal chemical meaning of 'oxidation' in favour of the more literary 'spoiled by the air'.

Cheers,

R.

 

[Freakscene]

Yes, a lot of things to think about. One interesting point is that films vary in the amount of developer they need to develop them properly. Their chemistry varies widely between types, speeds and manufacturer.

Marty

 

[Turtle]

I have also noticed that low dilution is often recommended for pushing films. If time is not an issue, wouldn't it be better to use a higher dilution to reduce the contrast, since pushed films are often already too contrasty.

Thanks.

Cheers,
Tony

Often people use concentrated developer to keep development times reasonable. I personally use relatively dilute developer for pushing for the very reason you suggest. I also reduce agitation. if I dont do this the highlights are blown to hell (say a window is in the frame). However, I recently pushed D3200 to 6400 where there were no light sources or real highlights. Just a dull interior. The results were great because the tonal range was considerably expanded which is exactly what the scene needed!

I if you like the negs you have, don't mess with what you do with important rolls. I would experiment with dilution. For example, there is a significant gain in bite/acutance with Xtol 1+2 compared to 1+0 say with TriX. Just trying a variety of devs as Roger says is also worth doing. Just develop Foma 100 in Xtol 1+1 then Rodinal 1+50 and they are chalk and cheese.

 

[randomT]

One thing I have always wanted to ask: apart from Rodinal, why can't I dilute infinitely other developers to achieve ultimate low contrast and sharpness? Say, what would happen if I dilute the DDX to 1:50?

I don't know the chemistry background, but most producers say that you need a certain amount of developer per film, regardless of the dilution, you can't dilute at will. For example, according to Agfa you need 10ml rodinal per film roll. From what I read, 5-6ml are sufficient, but with 10ml you are on the safe side. So, if I want to dilute Rodinal 1+100, I always use a 500ml (or better 900ml) tank and put only one reel in it. With a 300ml tank I would not dilute that much. Similarly, Kodak recommends to use at least 100ml stock Xtol per Film. So, while I prefer Xtol at 1+2 or 1+3, I only dilute it that much if my tank is big enough, otherwise I would use 1+1.


Something else to play around with is two bath development, haven't tried it myself yet, but it's on the list.

 

[Roger Hicks]

Yes, a lot of things to think about. One interesting point is that films vary in the amount of developer they need to develop them properly. Their chemistry varies widely between types, speeds and manufacturer.

Marty

Dear Marty,

I am always intrigued by the ones that load the emulsion with tons of development accelerators, such as Fuji 1600 and Foma 200. This is something I keep meaning to learn more about. Is it something you have studied at all?

Cheers,

R.

 

[ulrich.von.lich]

Thanks everyone!

Dear Roger, currently I only have DDX and use it at 1:4. Not that I'm not satisfied with the negatives, but if I can get similar or even better results at 1:9 (lower contrast will suit me better, and better sharpness won't hurt), why not? Plus, it'd be cheaper.

JB, that's interesting that you said higher dilution would lead to less grain. I remember reading the fine grain feature of Microdol X can only obtained with full power. If you use it at 1:3 it'd be no different than a classic developer like D76.

So higher dilution = lower contrast + better sharpness + less grain + cheaper ???

(Doesn't it sound too good to be true?)

Turtle, so is that it? Only a matter of time? I'd prefer to have better negatives than spending a little more time. Or will higher dilution with pushed film ever cause any problem? (What's the developing artifacts people talk about?) The problem is I can't seem to find the necessary information on digitaltruth.com. For example in my case I can only find the developing time for Neopan 1600 and DDX at 1:4, but not at 1:9.

 

[Leigh Youdale]

The problem is I can't seem to find the necessary information on digitaltruth.com. For example in my case I can only find the developing time for Neopan 1600 and DDX at 1:4, but not at 1:9.

That's probably because nobody (or not enough bodies anyway) is trying it. So it looks like you'll have to pioneer it yourself if you want to find out.

 

[Roger Hicks]

More dilution normally means slightly more grain and slightly more true ISO speed. DD-X at 1+9 should be especially suitable for Neopan because, as I recall, they're loaded with development accelerators and dev times are very short anyway. As a wild guess I'd start at about 60% longer than with 1+4, i.e. 7 minutes for the Neopan 1600.

Cheers,

R.

 

[ulrich.von.lich]

I will try it with a test roll.

But then, how should I tell if the time is a little short or long?

 

[charjohncarter]

I'm curious about the effects of temperature on the development characteristics. I use higher temperatures to shorten the development time but haven't done it enough to observe the difference between the standard 20c.

I can say agitation has an effect on contrast. When I agitate more I get more contrast, less agitation gets me less contrast. It is subtle though depending on how much agitation.

There is also a compensating effect associated with agitation reduction by increasing the time between cycles (example: 3 inversions every 3-4 minutes rather than 3 inversions every minute). The theory is that the shadows fully develop because of the smaller amount of exposed silver in these areas, but/and the exhaustion of the developer in the highlighted areas holds back complete development creating a good shoulder. So if you add this to your list without even changing developers you now have an infinite number of changes that can be made.

 

[Roger Hicks]

I will try it with a test roll.

But then, how should I tell if the time is a little short or long?

Ideally, with 3 rolls of static subjects (so you can shoot the same pic, varying only the exposure).

Bracket the exposure on all three. Try +/- 1 stop from the ISO figure. This gives you 12 pics per roll.

Develop one at 6 minutes, one at 7, one at 9.

See which gives you the pictures you like most...

Alternatively, just do the 7 minute roll. If they look a bit thin, go for 9 next time. If they're a bit dense, go for 6.

Cheers,

R.