Achieving more contrast with D-76

[138S]

is there a percentage increase on Ilford and Kodak times to aim for such as 10%

Kodak tells it in the datasheet, they plot contrast index vs development time. You have graphs for different processing conditions: small tank, large tank, trays and rotary:



With that you get a good guess for kodak products. Some graphs are a bit inconsistent, but still it shows how the CI grows with development time for each film-developer.

With ilford you have to experiement a bit, no problem.

 

[halfaman]

With something like this, I assume?
https://www.ebay.com/itm/160Pcs-PH-...078395?hash=item5d86d535bb:g:GTMAAOSwBLlVNLg5

Correct.

 

[138S]

or this: https://www.amazon.com/s?k=ph+meter&__mk_es_US=ÅMÅŽÕÑ&ref=nb_sb_noss_1

 

[koraks]

or this: https://www.amazon.com/s?k=ph+meter&__mk_es_US=ÅMÅŽÕÑ&ref=nb_sb_noss_1

That type sucks. I've tried a few and variations between individual specimens were huge; as large as 1.00. (Referring to the yellow or blue stick-like instrument. The cylindrical type is better)

 

[Alan Edward Klein]

I'm developing my Tmax film in a pro shop that uses D76 equivalent. I'm using the negatives for scanning. Anything I should know or advise them?

 

[138S]

That type sucks. I've tried a few and variations between individual specimens were huge; as large as 1.00. (Referring to the yellow or blue stick-like instrument. The cylindrical type is better)

Yes... this was a "search". One has to read opinions from customers to find a good model.

 

[M-88]

Kodak tells it in the datasheet, they plot contrast index vs development time. You have graphs for different processing conditions: small tank, large tank, trays and rotary:

View attachment 248098

With that you get a good guess for kodak products. Some graphs are a bit inconsistent, but still it shows how the CI grows with development time for each film-developer.

With ilford you have to experiement a bit, no problem.

I'm sorry, I'm not sure I follow. Does this graph mean that, let's say, what can be achieved with D-76 in 8 minutes, takes up to 14 minutes with HC-110? Or am I missing something?

 

[koraks]

Yes... this was a "search". One has to read opinions from customers to find a good model.

Yeah, I see.

My experiences so far with this type are good. It's fast, seems consistent and measures some more things besides pH:
https://www.wish.com/product/5e09e123672a5555d28ab1bb
It's available from a variety of sellers, but in the end it's apparently just a fairly generic Chinese consumer product that happens to work OK.

 

[138S]

Yeah, I see.

My experiences so far with this type are good. It's fast, seems consistent and measures some more things besides pH:
https://www.wish.com/product/5e09e123672a5555d28ab1bb
It's available from a variety of sellers, but in the end it's apparently just a fairly generic Chinese consumer product that happens to work OK.

thanks, I've to buy one and I'll follow your recommendation.

 

[138S]

I'm sorry, I'm not sure I follow. Does this graph mean that, let's say, what can be achieved with D-76 in 8 minutes, takes up to 14 minutes with HC-110? Or am I missing something?

Yes... some developers are faster than other, also see that Xtol sotck is faster than 1:1, not a surprise.

Reading that graph is quite straight, first you have a graph for each "tank type", so first you have to look at the right plot. Then the thing is easy, just take the curve for your developer and for each development time it says what Contrast Index you will get.

Remember that those graphs are starting points, developer age, particular agitation, temperature precision... all that has an influence, mostly those graphs show how CI grows with extended developer time.

 

[M-88]

Yes... some developers are faster than other, also see that Xtol sotck is faster than 1:1, not a surprise.

Reading that graph is quite straight, first you have a graph for each "tank type", so first you have to look at the right plot. Then the thing is easy, just take the curve for your developer and for each development time it says what Contrast Index you will get.

Remember that those graphs are starting points, developer age, particular agitation, temperature precision... all that has an influence, mostly those graphs show how CI grows with extended developer time.

I was double-checking, because D-76 seems to achieve same contrast index as other developers, but does it faster. My thought (apparently incorrect one) was that D-76 is a neutral developer.

 

[138S]

I was double-checking, because D-76 seems to achieve same contrast index as other developers, but does it faster. My thought (apparently incorrect one) was that D-76 is a neutral developer.

Yes... the graph shows that you can reach any C.I. with any developer, but each developer does it with a particular speed.

In fact developer makes several things, but each soup makes each thing at different speed. First a developer has an "induction time" before a significative development starts. Later developer has to start developing exposed crystals which takes place more or less faster depending on agents REDOX potential and etc, but another process we call "infectious development" that develops non exposed crystals that are close those developed yet, pH is an important factor for that infectious developing speed. The silver solvent also has interactions with all that...

Well, with all developers we may obtain a low or a high C.I. , the question is about the nuances, some will show more or less grain for the same C.I. or more or less fog...

Those graphs in the Kodak datasheets are only relatively useful in practice, but the important thing is that they conceptually show how processing can be adjusted and what C.I. sensitivity we have to development time.

 

[mklw1954]

Are you developing with some form of temperature control? Lower than 68F can result in some underdevelopment and flatness/lack of contrast. I have no problem getting good contrast negatives with stock D76 at the recommended times and agitation, shooting box film speed, and using a simple system of temperature control with a small insulated cooler.

 

[baachitraka]

Thank you! I read it but my mind is not clear enough right now. I'll get back to it when I'm off duty. Either way it seems I'll have to sacrifice a couple of rolls.

He was more of a portraitist. So he based the exposure on one incident reading (dome facing the camera for the obvious reasons) and depend on lighting he chooses the developers (Rodinal on dull day etc.,)

But the variation comes from how it was developed. That is, develop longer with sparse agitation

For Rodinal and I presume for other mentioned developers, he agitates at every five minutes for 10s.

Intrestingly this leads to a push to shadow details and pull to highlights (kind of perfect) also he make no adjustment to film speed.

But not all film are good for this scheme. Luckily HP5+ seems good (corrections apply)

 

[MattKing]

At last someone who prefers healthy negatives (versus wimpy negatives)

To my mind, wimpy negatives are under-exposed negatives, not under-developed ones.
Under-developed negatives are just quiet .

 

[MattKing]

I was double-checking, because D-76 seems to achieve same contrast index as other developers, but does it faster. My thought (apparently incorrect one) was that D-76 is a neutral developer.

I'm not sure what would make a developer "neutral".
All developers are different. Each developer will have standard times for particular films, and those times will be dependent on a bunch of criteria, including the desired contrast.
And if a combination of film, developer, scanner and scanner software combination doesn't typically give you files that look pleasing to you, check to see whether your scanning software allows you to record a set of standard adjustments in a profile. Then make those adjustments, record them, and use that profile for that combination.

 

[M-88]

Are you developing with some form of temperature control? Lower than 68F can result in some underdevelopment and flatness/lack of contrast. I have no problem getting good contrast negatives with stock D76 at the recommended times and agitation, shooting box film speed, and using a simple system of temperature control with a small insulated cooler.

Sure, I have this non-inversible tank which has a wiggly thing in the middle and it doubles as a thermometer. It's not the best solution, but it gets the job done. I always develop at 21-22 celsius, that would be a little more than 68F. Tank is plastic and it keeps the temperature quite well as long as ambient temperature is adequate.

Yes... the graph shows that you can reach any C.I. with any developer, but each developer does it with a particular speed.

In fact developer makes several things, but each soup makes each thing at different speed. First a developer has an "induction time" before a significative development starts. Later developer has to start developing exposed crystals which takes place more or less faster depending on agents REDOX potential and etc, but another process we call "infectious development" that develops non exposed crystals that are close those developed yet, pH is an important factor for that infectious developing speed. The silver solvent also has interactions with all that...

Well, with all developers we may obtain a low or a high C.I. , the question is about the nuances, some will show more or less grain for the same C.I. or more or less fog...

Those graphs in the Kodak datasheets are only relatively useful in practice, but the important thing is that they conceptually show how processing can be adjusted and what C.I. sensitivity we have to development time.

Everything is "relatively useful" in this life, once we learn how to do things by the book, we start thinking outside the box. At least now I know what to do with my next roll and I'll be more prepared for surprises.

I'm not sure what would make a developer "neutral".
All developers are different. Each developer will have standard times for particular films, and those times will be dependent on a bunch of criteria, including the desired contrast.
And if a combination of film, developer, scanner and scanner software combination doesn't typically give you files that look pleasing to you, check to see whether your scanning software allows you to record a set of standard adjustments in a profile. Then make those adjustments, record them, and use that profile for that combination.

I got lost in translation. I meant it's a "leveling developer", which has relatively low pH and ensures a "leveled" contrast for sake of pulling out shadow detail. In other words, "not a high contrast developer by default". I don't know if it makes sense, most of my literature is in Яussian.

 

[Doremus Scudder]

I have read how dilution affects sharpness and grain, but I had no info about contrast. That is why I opened the thread about contrast, not about sharpness or grain, both of which I can control.

Adjusting contrast with a change in developer dilution or development time is basic to analog photography. I assume that anyone who is developing his/her own negatives has learned this already. If you hadn't, then I apologize for the incorrect assumption.

As you are learning, each developer formula and each different dilution has a unique development time to achieve a specific contrast index. Finding the ideal time for the developer you choose and the film you are using is just part of the process. Negs too flat? Increase development time (all other things being equal, of course). And vice-versa. Experiment till you get the contrast you desire from your negatives. Keep in mind that the subject brightness range affects the final distribution of tones in the negative, regardless of the contrast index you develop to. That's why Zone System users develop longer for flat scenes and less for contrasty scenes.

Finding your personal film speed (i.e. the speed that gives you the shadow values you desire in the final print) is an important part of the process. Play around with film speed as well as development times. I didn't get good negatives with a full range of tones till I started exposing my film correctly (for me).

Best,

Doremus

 

[Doremus Scudder]

Doremus, this is right, but extending development time also affects the appearance of the grain, coarser.

138S,

You're right, of course, all other things being equal. This latter is the important part, since all other things are usually not equal. Actually, the apparent graininess (with a specific developer/dilution) varies with density.

Yes, an underdeveloped negative will have less apparent graininess in its most dense areas. The correctly-developed negative will have more density in the highlight areas than the underexposed one and therefore show more apparent graininess in those denser areas... But, the range of tones in the negative will be more correct for making the final print. We live with whatever grain we need to get the job done as far as correct development is concerned.

The graininess characteristics of films are largely baked-in and dependent on emulsion speed and formula anyway. The choice of developer (silver-solvent or not) has an effect on the grain rendering, but this is at a smaller scale.

Sure, more development results in more apparent graininess, but that's not a reason to underdevelop your film. If you need less grain, get a slower film and/or a larger format.

Best,

Doremus

 

[Doremus Scudder]

To my mind, wimpy negatives are under-exposed negatives, not under-developed ones.
Under-developed negatives are just quiet .

I love this!

 

[M-88]

Adjusting contrast with a change in developer dilution or development time is basic to analog photography. I assume that anyone who is developing his/her own negatives has learned this already. If you hadn't, then I apologize for the incorrect assumption.

If that is so, then I'm afraid I'm a complete dunce in this subject.

 

[138S]

If that is so, then I'm afraid I'm a complete dunce in this subject.

Well, Large Format photographers are more prone to adjusting development, as we can do an specific custom development for each individual sheet. Instead with rolls we have to make a development that's suitable "in general" for all the shots in the roll.

Mostly that kind of custom development is useful for scenes with a lot of dynamic range, if we want to record detail in the deep shadows we may have to use an exposure that's enough for those shadows, the drawback is that highlights will be quite overexposed to the point that detail can be lost there, or it would be difficult to print, so the trick is underdeveloping to not allow the highlights reach a too high density.

A very old say: Expose for the shadows and develop for the highlights... This may deliver a lower contrast negative that it may not be easy to print, but it would contain good detail in the shadows and highlights, by underdeveloping we extend the nominal film latitude.

 

[Doremus Scudder]

If that is so, then I'm afraid I'm a complete dunce in this subject.

Not at all!!

You've got enough information in this thread already to make you an expert

Problems arise with the normal sequence of adjusting developing time to get the contrast you need for printing when your "printing" involves scanning, however.

In a purely analog workflow, one strives to find a development time that consistently gives negatives that print well on a medium-contrast-grade paper (e.g., grade 2 or 2.5). That gives lots of leeway on either side to deal with negatives from very contrasty or very flat scenes. Scanning throws a whole bunch of other variables into the mix in the form of automatic adjustments by the scanning software, etc. Still, the goal is the same: find a film speed and development time that works for you and gives you prints you like.

None of the manufacturers' recommendations are carved in stone; they are simply starting points. Every black-and-white photographer finds their own combination of personal film speed and development time.

It doesn't have to be complicated either (like the Zone System or BTZS). Just follow Kodak's simple advice:

If your negatives consistently need more shadow detail, expose more (i.e., use a lower effective film speed or E.I.). And vice-versa.
If your negatives are consistently too flat, develop longer, and vice-versa.

Keep playing around with the variables till you find what you need in terms of good shadow detail and negative contrast.

Best,

Doremus

 

[Bormental]

Great thread!

Scanning throws a whole bunch of other variables into the mix in the form of automatic adjustments by the scanning software, etc.

This came up a few times already, and that is why I am a big advocate for DSLR scanning. Camera RAW workflow is just more flexible and "fluid" for B/W film work. The user interface tends to be more modern and easy (LR, C1) and you can turn off all automatic features and have a beautiful linear RAW file as a starting point, save your own levels/curves as presets for emulsion+developer combinations, it is much more enjoyable and faster than pulling teeth with scanner software.

 

[Adrian Bacon]

Adrian, can you amplify what you have quoted in my first two sentences above. What is the standard by which you are judging the high side i.e high side of what as you then go on to say that both are below ISO contrast

I checked your times on your website and for HP5+ in replenished Xtol at 75F you quote 7 mins which is a 10% increase on what Kodak gives for 75F as it quotes 6 mins 15secs so I can see that your times will give a greater contrast that Kodak's own times. I am assuming in this that replenished Xtol for the purposes of time comparison is the equivalent or as near as damn it the equivalent of stock Xtol

The puzzle arises when we look at Ilford's times for Xtol. Ilford's time is 8 mins Xtol @ 68F which on Ilford's temperature compensation chart drops to about 5mins 30 sec. Ralph Lambrecht's chart show it as 8 mins to 5 mins so a slight further reduction. However what stands out is that the Ilford time for stock Xtol at 75F is actually less than the Kodak time by 45 secs which at the time quoted is appreciable.

So based on these times it would appear that Ilford's time should result in a lower contrast than Kodak's which seems contrary to the point you makes when you say Ilford tends to be on the high side

Finally can I ask what is ISO contrast compared Kodak or Ilford contrast in terms of numbers and if users want to aim for ISO contrast how is this worked out and for those not able to do the maths is there a percentage increase on Ilford and Kodak times to aim for such as 10%

Thanks

pentaxuser

Ilford does not supply times for replenished xtol. Replenished xtol is not the equivalent to stock xtol, not even close. It’s more like 1+1 to 1+2 depending on the film, and Kodak very clearly states that the times they list in J-109 are starting points. You have to adjust from there after you test. The temperature and agitation will affect highlight density quite a bit. The only thing you can do is test and adjust the time.

ISO contrast is 0.615 (round up to 0.62). If you use Kodak’s times for Kodak’s films, you end up at ~0.56. With ilford, you end up approximately 0.58-0.60. Ilford generally is a little more contrast than Kodak, but both are less contrast than 0.62, Kodak by quite a lot, Ilford by just a little.