What variables are you controlling with Time?

RattyMouse · Mar 23, 2014

I can develop a roll of film using HC-110 at 5 mins using dilution B or 7 mins with dilution E. What variables am I controlling by changing the time of development (along wit dilution strength)? I understand what time does when you keep the dilution the same, but when the dilution is changing along with time, it is not clear to me what is achieved, if anything at all (besides economics due to less syrup being used in the weaker dilutions).

Thanks!

NedL · Mar 24, 2014

Ratty, your other thread got me wondering the same thing. For each given dilution I've seen the difference time makes in density and contrast with my own eyes... I have "dialed in" times for the films and dilutions I use for my way of printing, but you got me wondering what the difference would be if I "dialed in" the time for a different dilution. I can't easily compare printing them directly since all my dilution D is 35mm and all my dilution E is 120 film.

Tom1956 · Mar 24, 2014

You are controlling your personal economics and evenness of development at higher dilutions at the same time. Anybody who has seen as many Kodak publications as I have can cite chapter-and-verse the admonition about "development uniformity at times shorter than 5 minutes" at the bottom of every small-tank developer chart. And at that point is where you simply trust to faith that the chemists and scientists at Kodak have worked out the variables to the nth degree when they went to press with these charts. What else is there to question?

Bill Burk · Mar 24, 2014

Hey,

I just read about this over on Post #64 by Michael R 1974...

His point: With D-76, a solvent developer, there will be a difference based on different dilutions. But with HC-110, not so much...

(there was a url link here which no longer exists)

Tom1956 · Mar 24, 2014

Michael R has made something of an impression on these developer questions.

RattyMouse · Mar 24, 2014

Bill Burk said:
Hey,

I just read about this over on Post #64 by Michael R 1974...

His point: With D-76, a solvent developer, there will be a difference based on different dilutions. But with HC-110, not so much...

(there was a url link here which no longer exists)

Yeah, I'm not entirely understanding this, hence my question. With the developer concentration connected to time (longer, more dilute, shorter time, more concentrated), that removes a major variable. I'm left wondering what the time difference here does to the final output.

Tom1956 · Mar 24, 2014

Hair splitting. Time is your friend for the sake of development evenness.

Gerald C Koch · Mar 24, 2014

A person presented with prints from two negatives both correctly developed (one in dilution B and one in dilution E) would be hard pressed to distinguish between them Remember that the various dilutions devised by Kodak are not capricious ones. They allow commercial processors to duplicate the results of different developers like D-76 and DK-50 without reprograming their machines. Each dilution will provide excellent results when used correctly.

Xmas · Mar 24, 2014

the dilution is not exactly the same as time or temperature variation

eg there are two mechanisms for simplicity...
diffusion of developer into the emulsion vertically
diffusion of developer horizontally ie along the film

in shadows the developer is not doing anything
in the highlights it is used up apart from the new stuff diffusing in vertically and from local shadows

If the developer is very dilute the edge of the highlights are developed more than the bodies similarly the edges of shadows less from fresh developer diffusing one direction exhausted other

so weak (dilute) developers do produce apparently sharper edges like photshops digital sharpen...

It is more complicated the developer efficiency ie reaction rate and diffusion rate need not have the same temperature dependency etc., ...

So keep everything the same time temp dilution agitation, and your negs will be the same as yesterday.

I dev stop fix and clear at 20c within a degree to minimise risk never agitate all repeatable...

When you wetprint and burn and dodge with different contrast filters you need a metronome and a tape recorder one two burn the left eye one two burn the right eye. Playing piano is simpler...

gone · Mar 24, 2014

I hesitate to say anything, as this subject is often like the Unitarians arguing w/ the Unitarian Universalists, meaning there are a lot of tightly held beliefs over a not-so-visible issue. I would suggest trying it yourself and see what you like. Myself, I normally go for the shortest time to get the job done, but stay away from times of under 6 minutes if I can. About all I use for film developing is D76 (or the TD-16 version), Rodinal and Acufine, w/ 90% of the developing being D76/TD-16. My film is always Tr-X, so that simplifies things. With the latter developer, I prefer to use it full strength. A lot of people prefer it at 1:1. I just prefer the look of full strength developed negs, no other reason. Most people prefer Rodinal at 1:50 or 1:100 dilutions, I have a development scheme that gives me what I want at 1:25. Again, it's just for what I like, no other reason. I also don't like very long developing times as that just gives me more opportunities to screw up.

It basically comes down to what you prefer, and the only way to see which is which it is to try it and see. I have no idea on what the chemical reasons are for preferring one type of scheme to another, really. There are a lot more knowledgeable people on this forum than I when it comes to the hows and whys of the chemistry, but I don't need to know all that in most cases. Testing things myself and seeing what the results of that testing are is something that works very well for me. I would certainly stay away from times below 5 minutes for obvious reasons.

markbarendt · Mar 24, 2014

Think of it the other way round Ratty. Dilution can be adjusted to get to the time we prefer.

Very short development times are inherently less forgiving of process variations and in some cases may lead to uneven development.

Adjusting dilution to get a 10-minute time, instead of 4-minutes, may get the user more consistent results. For example, a distraction causing a 30-second variation in a 4-minute cycle is much more significant than a 30-second variation in a 10-minute cycle.

The difference isn't necessarily a straight line difference between the two times above either. Part of what's happening when the chemicals first go in the tank is getting the gelatin to swell enough so that the developer can get access to the all the exposed silver. I have no idea how long that takes but with short development times it could be a significant %.

ic-racer · Mar 24, 2014

RattyMouse said:
What variables am I controlling by changing the time of development (along wit dilution strength)?

Volume of active developer.

MattKing · Mar 24, 2014

I don't know why, but HC-110 seems to give me similar results even when I vary dilution. It would make sense that Kodak would have designed it that way, but I cannot say with certainty that they did.

jcc · Mar 24, 2014

ic-racer said:
Volume of active developer.

Also number agitation. Or does that not affect anything?

jerrybro · Mar 24, 2014

markbarendt said:
Think of it the other way round Ratty. Dilution can be adjusted to get to the time we prefer.

Very short development times are inherently less forgiving of process variations and in some cases may lead to uneven development.

Adjusting dilution to get a 10-minute time, instead of 4-minutes, may get the user more consistent results. For example, a distraction causing a 30-second variation in a 4-minute cycle is much more significant than a 30-second variation in a 10-minute cycle.

The difference isn't necessarily a straight line difference between the two times above either. Part of what's happening when the chemicals first go in the tank is getting the gelatin to swell enough so that the developer can get access to the all the exposed silver. I have no idea how long that takes but with short development times it could be a significant %.

I think Mark nailed it, as long as we agree on 1 thing, that the amount of active developer required per the area developed is sufficient. I use D23 and have gotten the same curves at 1:1 and 1:3 with an adjustment of time. The longer time at 1:3 helps me eliminate any errors in handling as the error time to developing time is smaller at the higher dilution. That has also made me question the compensating effects observed at higher dilutions, as I suspect they are really the results of developer exhaustion. I have also experimented with different developers and can get pretty much the same curves by tweaking dilution, time and temp.

jcc · Mar 24, 2014

momus said:
... I prefer to use it full strength. A lot of people prefer it at 1:1. I just prefer the look of full strength developed negs, no other reason. Most people prefer Rodinal at 1:50 or 1:100 dilutions, I have a development scheme that gives me what I want at 1:25. Again, it's just for what I like, no other reason. ...

Doesn't this kind of answers (yet vaguely) the OP's question? What effect does time/dilution have on negs? How does the "look" differ?

Bill Burk · Mar 24, 2014

Michael R 1974 said:
Bill, all,

To clarify, this is not what I said. I said as a solvent developer, HC-110 should be subject to the same dilution effects as other PQ/MQ solvent developers.

I stand corrected. I should have checked that simple fact. Thanks for the clarification.

Rudeofus · Mar 25, 2014

Michael R 1974 said:
I said as a solvent developer, HC-110 should be subject to the same dilution effects as other PQ/MQ solvent developers. My point was that for some reason when it comes to HC-110, people don't seem apply the same thought/logic to dilution choice as they do with other developers. I don't have an answer for why they don't.

There is general consensus here on APUG that for Sulfite to have solvent property, you need at least 50 g/l Sodium Sulfite or the equivalent from some other Sulfite source. We know that Sulfite ion is provided as TEA.SO2 addition product. From the molar weights of TEA, SO2 and Na2SO2, you need roughly twice as much TEA.SO2 than you would have to add Na2SO2 to match the amount of [/SUB]SO3--.

This means, for solvent property you'd need over 100 ml/l HC-110, which is more concentrated than dilution A and assumes that HC-110 is mostly TEA.SO2. Unless HC-110 contains another solvent that I am not aware of, I would consider HC-110 a non-solvent developer for all practical purposes.

Rudeofus · Mar 25, 2014

Michael R 1974 said:
You might be right, Rudi, but according to Kodak, HC-110 is supposed to function similarly to D-76. It is also speculated PVP is included in the HC-110 formula to help control undesirable solvent effects which could result from the use of "powerful forms of sulfite..." (Anchell/Troop) - not that I'm saying this is necessarily correct.

The presence of a compound to prevent dichroic fog (PVP) strongly suggests, that HC-110 is indeed a solvent developer. Some stronger solvent than the SO2, most likely 2-Aminoethanol, must be present.

peter k. · Mar 25, 2014

A little bit off topic perhaps, but in post #9,

If the developer is very dilute the edge of the highlights are developed more than the bodies

Xmas you may have just given me the reason why when I shoot Arista 400 EDu 400, shot at 200, (or 400 for that matter, but it has a little more, but not much) is giving me a slight burnout, in the sky highlights... no where else. Not in any of the bright contrasty foliage or objects at ground level. I have been experimenting with less agitation, but it didn't seem to make a difference, and didn't like the contrast result in the rest of the negative.
Soooo... Didn't know what to do next, I think I will try a different dilution, as in developing other films, I find I found I liked the dilution H the best, for the results I wanted. But maybe not for this one.
Thanks...

markbarendt · Mar 25, 2014

peter k. said:
A little bit off topic perhaps, but in post #9,

Xmas you may have just given me the reason why when I shoot Arista 400 EDu 400, shot at 200, (or 400 for that matter, but it has a little more, but not much) is giving me a slight burnout, in the sky highlights... no where else. Not in any of the bright contrasty foliage or objects at ground level. I have been experimenting with less agitation, but it didn't seem to make a difference, and didn't like the contrast result in the rest of the negative.
Soooo... Didn't know what to do next, I think I will try a different dilution, as in developing other films, I find I found I liked the dilution H the best, for the results I wanted. But maybe not for this one.
Thanks...

Sounds like you can get very close to where you want to be with the film, I kinda doubt the film is blocking, most films have lots of "extra room" for even very bright highlights. It should be pretty easy to use printing controls to finish the job; a taste of pre-flash on the paper, or a little burn in the highlights, or maybe a half grade paper adjustment.

Have you played with these?

peter k. · Mar 25, 2014

Alas, I am hybrid, film and develop and then scan as I do not have a proper darkroom.

markbarendt · Mar 25, 2014

peter k. said:
Alas, I am hybrid, film and develop and then scan as I do not have a proper darkroom.

That doesn't change your ability to make these minor changes. Using printing controls are a natural and normal part of using negative film.

RalphLambrecht · Mar 25, 2014

Tom1956 said:
Hair splitting. Time is your friend for the sake of development evenness.

the question is valid.How does dilution and time affect grain and sharpness
I assume,with dilutiondev time increases and so does grainand acutance,correct?:confused:

Gerald C Koch · Mar 26, 2014

From what I have read PVP is used to prevent sludging and is not directly involved with solvency.

What variables are you controlling with Time?

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