What are the different effects of times and dilutions?

As the title says, I'm just trying to get a grip on what the effect is of using different times and dilutions for the same developers.

As an example, the below times are random films and developers, pulled right off the MDC. Why would you choose one method over the other? Does one produce better contrast, finer grain, etc.?

[TABLE="class: mdctable, width: 708"]

[TD="class: left nobr"]FP4+[/TD]
[TD="class: left"]D-76[/TD]
[TD="class: center, align: center"]1+1[/TD]
[TD="class: center, align: center"]50[/TD]
[TD="class: center, align: center"]8[/TD]
[TD="class: center, align: center"]8[/TD]
[TD="class: center, align: center"]8[/TD]
[TD="class: center, align: center"]20C[/TD]
[TD="class: center, align: center"][/TD]


[TD="class: left nobr"]FP4+[/TD]
[TD="class: left"]D-76[/TD]
[TD="class: center, align: center"]1+3[/TD]
[TD="class: center, align: center"]50[/TD]
[TD="class: center, align: center"]17[/TD]
[TD="class: center, align: center"]17[/TD]
[TD="class: center, align: center"]17[/TD]
[TD="class: center, align: center"]20C[/TD]

[/TABLE]

[TABLE="class: mdctable, width: 708"]



[TD="class: left nobr"]Ilford Pan 100[/TD]
[TD="class: left"]D-76[/TD]
[TD="class: center, align: center"]stock[/TD]
[TD="class: center, align: center"]100[/TD]
[TD="class: center, align: center"]7[/TD]
[TD="class: center, align: center"][/TD]
[TD="class: center, align: center"][/TD]
[TD="class: center, align: center"]20C[/TD]
[TD="class: center, align: center"][/TD]


[TD="class: left nobr"]Ilford Pan 100[/TD]
[TD="class: left"]D-76[/TD]
[TD="class: center, align: center"]1+1[/TD]
[TD="class: center, align: center"]100[/TD]
[TD="class: center, align: center"]10[/TD]
[TD="class: center, align: center"][/TD]
[TD="class: center, align: center"][/TD]
[TD="class: center, align: center"]20C[/TD]
[TD="class: center, align: center"][/TD]


[TD="class: left nobr"]Ilford Pan 100[/TD]
[TD="class: left"]D-76[/TD]
[TD="class: center, align: center"]1+3[/TD]
[TD="class: center, align: center"]100[/TD]
[TD="class: center, align: center"]16[/TD]
[TD="class: center, align: center"][/TD]
[TD="class: center, align: center"][/TD]
[TD="class: center, align: center"]20C[/TD]

[/TABLE]

[TABLE="class: mdctable, width: 708"]

[TD="class: left nobr"]Adox CHS 100[/TD]
[TD="class: left"]Rodinal[/TD]
[TD="class: center, align: center"]1+25[/TD]
[TD="class: center, align: center"]100[/TD]
[TD="class: center, align: center"]6[/TD]
[TD="class: center, align: center"]6[/TD]
[TD="class: center, align: center"]6[/TD]
[TD="class: center, align: center"]20C[/TD]
[TD="class: center, align: center"][/TD]


[TD="class: left nobr"]Adox CHS 100[/TD]
[TD="class: left"]Rodinal[/TD]
[TD="class: center, align: center"]1+50[/TD]
[TD="class: center, align: center"]100[/TD]
[TD="class: center, align: center"]10[/TD]
[TD="class: center, align: center"]10[/TD]
[TD="class: center, align: center"]10[/TD]
[TD="class: center, align: center"]20C[/TD]

[/TABLE]

[TABLE="class: mdctable, width: 708"]

[TD="class: left nobr"]Arista Premium 400[/TD]
[TD="class: left"]Rodinal[/TD]
[TD="class: center, align: center"]1+25[/TD]
[TD="class: center, align: center"]400[/TD]
[TD="class: center, align: center"]7[/TD]
[TD="class: center, align: center"][/TD]
[TD="class: center, align: center"][/TD]
[TD="class: center, align: center"]20C[/TD]
[TD="class: center, align: center"][notes][/TD]


[TD="class: left nobr"]Arista Premium 400[/TD]
[TD="class: left"]Rodinal[/TD]
[TD="class: center, align: center"]1+35[/TD]
[TD="class: center, align: center"]400[/TD]
[TD="class: center, align: center"]10[/TD]
[TD="class: center, align: center"][/TD]
[TD="class: center, align: center"][/TD]
[TD="class: center, align: center"]20C[/TD]
[TD="class: center, align: center"][notes][/TD]


[TD="class: left nobr"]Arista Premium 400[/TD]
[TD="class: left"]Rodinal[/TD]
[TD="class: center, align: center"]1+50[/TD]
[TD="class: center, align: center"]400[/TD]
[TD="class: center, align: center"]13[/TD]
[TD="class: center, align: center"][/TD]
[TD="class: center, align: center"][/TD]
[TD="class: center, align: center"]20C[/TD]

[/TABLE]


I'm just trying to get a better understanding of the process.

Thanks

You cannot really rely on the MDC for anything other than guaranteed inconsistency.

For a much better resource, refer to the manufacturer's data sheets. You can have some confidence that the manufacturer will have tested the alternatives in similar circumstances, using similar criteria.

To a certain extent, your question can be meaningfully answered for each (type of) developer, although in some cases the answer will vary between films.

In general though, you can achieve desired contrast using any developer at any normal dilution by adjusting the time. You will just need to experiment, because each (type of) developer will require its own adjustment.

Reasons to dilute developer:

1) Factory recommendation. Example: T-max developer is recommended to be diluted 1:4
2) Prolong development times. Example: HC110 can be diluted to match the times of other developers for convenience
3) Increase developer volume to cover film in tank. Example D-76 1:1 for inversion processing in Jobo 2500 drums.

NON-Reason:
1) Economy. Example: both straight and 1:1 D-76 process the same amount of film. The capacity is NOT doubled.

Let's try this another way.

Using the below example, why would someone choose one of the dilution/time recommendations over one of the others? ie., why would someone choose to develop their Arista Premium 400 with Rodinal at 1+25 for 7 minutes, rather than 1+50 for 13 minutes, or vice verse? How will the results differ, if at all?


[TABLE="class: mdctable, width: 708"]

[TD="class: left nobr"]Arista Premium 400[/TD]
[TD="class: left"]Rodinal[/TD]
[TD="class: center, align: center"]1+25[/TD]
[TD="class: center, align: center"]400[/TD]
[TD="class: center, align: center"]7[/TD]
[TD="class: center, align: center"][/TD]
[TD="class: center, align: center"][/TD]
[TD="class: center, align: center"]20C[/TD]
[TD="class: center, align: center"][notes][/TD]


[TD="class: left nobr"]Arista Premium 400[/TD]
[TD="class: left"]Rodinal[/TD]
[TD="class: center, align: center"]1+35[/TD]
[TD="class: center, align: center"]400[/TD]
[TD="class: center, align: center"]10[/TD]
[TD="class: center, align: center"][/TD]
[TD="class: center, align: center"][/TD]
[TD="class: center, align: center"]20C[/TD]
[TD="class: center, align: center"][notes][/TD]


[TD="class: left nobr"]Arista Premium 400[/TD]
[TD="class: left"]Rodinal[/TD]
[TD="class: center, align: center"]1+50[/TD]
[TD="class: center, align: center"]400[/TD]
[TD="class: center, align: center"]13[/TD]
[TD="class: center, align: center"][/TD]
[TD="class: center, align: center"][/TD]
[TD="class: center, align: center"]20C[/TD]

[/TABLE]

And to use T-Max as an example, the data sheet says:

These development times should produce negatives with a contrast suitable for printing with a diffusion enlarger. To adjust
contrast for printing with a condenser enlarger, reduce the
development time by 20 to 30 percent.

Click to expand...

By reducing the development time by 20-30%, will that increase apparent contrast, or decrease it (I don't know the differences between a diffusion and condenser enlarger are, as I only scan)?

Kirks518 said:

Using the below example, why would someone choose one of the dilution/time recommendations over one of the others?

Click to expand...

Changing the dilution can affect the grain structure of the negative and/or the shape of the characteristic curve (tonal scale). The magnitude and character of the changes varies from one film/developer combination to another, though in general the effects are relatively modest in current films compared to what one might have observed in films of decades past.

One reason is that for consistency i like to keep development times above 5 minutes. When using rotatry processing, trying to achieve a N-2 development I need about 5.5 minutes in a 1+2 dilution with XTOL to get the desired contrast for my condensor enlarger. Using 1+1 would give times a bit over 4 minutes, which is would be tricky for the way I work. I decided to standardize all my rotary processing on the 1+2 dilution, even when N-1 would not need it, because dilution also has an effect on speed, grain and sharpness. Quotation from the Kokak publication j109 on XTOL: "You can dilute XTOL Developer 1:1 with water (developer:water) for one-shot (single-use) processing. Dilution at 1:1 will provide slightly greater film speed, enhanced sharpness and shadow detail, and slightly more grain." I also found this to be true for Rodinal on Tri-X: I much prefer how the negatives look when developed with 1+50 over the ones i did with 1+25, even when developed to around the same contrast.

Longer development times will give you higher contrast in the negative. All other things being equal, this will lead to higher contrast in the print.
Shorter development times will give you lower contrast in the negative. All other things being equal, this will lead to lower contrast in the print.

A condenser enlarger will give you slightly higher contrast in the print.
A diffusion enlarger will give you slightly lower contrast in the print.

In general, we make our contrast decisions with the final print in mind.

So if you are tailoring your development to a particular printing paper, you would normally develop less for a (high contrast) condenser enlarger then you would for a (slightly lower contrast) diffusion enlarger.

This was particularly important in the past, when printing paper only came in fixed contrast grades.

In these days of variable contrast printing paper, far less worry is expended on matching the contrast to the paper.

There still are those, however, who used fixed contrast grade papers.

If you do it the old school way, where expert craftsmen knew exactly what they needed to do to get exactly what they wanted from their negatives, developer dilution could play a large role based on what kind of print they wanted, and what kind of light they were shooting in.

If you develop film at 1+50 instead of 1+25, you will have to develop longer to compensate for lost developer activity. That means shadows get more developed, so you do get a bump in the shadow detail and film speed department. Usually this also changes the slope of the tone curve. With more dilute developer you may develop a shoulder on a film such as FP4+ or Tri-X (Arista Premium 400), which wouldn't be there at 1+25.
These small differences could matter a great deal to the final appearance of a print.

Today I just think it's down to practicality, maybe economy in using as little film developer as possible, or whatnot.

Kirks518 said:

Let's try this another way.

Using the below example, why would someone choose one of the dilution/time recommendations over one of the others? ie., why would someone choose to develop their Arista Premium 400 with Rodinal at 1+25 for 7 minutes, rather than 1+50 for 13 minutes, or vice verse? How will the results differ, if at all?


[TABLE="class: mdctable, width: 708"]

[TD="class: left nobr"]Arista Premium 400[/TD]
[TD="class: left"]Rodinal[/TD]
[TD="class: center, align: center"]1+25[/TD]
[TD="class: center, align: center"]400[/TD]
[TD="class: center, align: center"]7[/TD]
[TD="class: center, align: center"][/TD]
[TD="class: center, align: center"][/TD]
[TD="class: center, align: center"]20C[/TD]
[TD="class: center, align: center"][notes][/TD]


[TD="class: left nobr"]Arista Premium 400[/TD]
[TD="class: left"]Rodinal[/TD]
[TD="class: center, align: center"]1+35[/TD]
[TD="class: center, align: center"]400[/TD]
[TD="class: center, align: center"]10[/TD]
[TD="class: center, align: center"][/TD]
[TD="class: center, align: center"][/TD]
[TD="class: center, align: center"]20C[/TD]
[TD="class: center, align: center"][notes][/TD]


[TD="class: left nobr"]Arista Premium 400[/TD]
[TD="class: left"]Rodinal[/TD]
[TD="class: center, align: center"]1+50[/TD]
[TD="class: center, align: center"]400[/TD]
[TD="class: center, align: center"]13[/TD]
[TD="class: center, align: center"][/TD]
[TD="class: center, align: center"][/TD]
[TD="class: center, align: center"]20C[/TD]

[/TABLE]

Click to expand...

For an example, this is taken directly from the Xtol datasheet

You can dilute XTOL Developer 1:1 with water
(developer:water) for one-shot (single-use) processing.
Dilution at 1:1 will provide slightly greater film speed,
enhanced sharpness and shadow detail, and slightly more
grain.

Click to expand...

As has been said above, diluting and developing longer (most famously Rodinal) leads to local-exhaustion of the developer in the highlights while the shadows keep developing -> more shadow detail and less contrast. At the extremes of 1+100 or 1+200 stand developing, you can cover up some metering errors and underexposure (although it's not the magic bullet some claim).

Keeping times above 5 minutes is also a good idea, as said. Cooling down to 16C or less to increase times is not a good idea.

Also, I'd say economy is a perfectly valid reason. I try to use Rodinal at 5 - 10ml per roll or per 8x10 sheet. If I fill my Multitank 5 and CL81 full for regular inversion-developing (not rolling on the Jobo), it takes about 2L. At 1+25 that's 80ml of rodinal, for three (or sometimes even one) 8x10 sheet(s), 75ml of wastage there. At 1+100 I only need 20ml, that's about perfect for 3 sheets, and not too much wasted for one sheet. And given that my 8x10 shutter has only T, B, and 1/50s, more dilution and less contrast helps cover up the fact that it's probably not exposed properly.

Wow! Thanks all. I get it now. Matt King, I appreciate the rundown on everything in a way it makes perfect sense. And to the rest of you, my hat's off for taking the time to elaborate/expand to help as well.

You guys rock!

Here's an example of what different developer dilution and alteration of agitation and developing time will actually do. It is so well written and illustrated.

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

Michael R 1974 said:

Most of what you will read about developer dilutions on the subject of things like contrast, film speed and tone reproduction is, well, not very good. Much of it is just age-old tradition, not based on what really happens. People swear by things, but they usually don't know what they're actually getting. We all see what we want to see, but we don't really have as much control over negative development as we think we do.

Click to expand...

I agree that differences are usually smaller than what is reported. But I can tell from a few years of doing it that I see significant difference between agitating every minute versus agitating every five minutes (and compensating dev time to make up for lost activity for similar total contrast).

I know what I see. I don't make it up to feel good about it.

Kirks518 said:

(I don't know the differences between a diffusion and condenser enlarger are, as I only scan)?

Click to expand...

a cold light head ( diffusion ) requires a denser negative ( sometimes a "brighter" light source ), and kodak used to actually print instructions and include them
with every roll that said something like " increase development by 30% if using a diffusion / cold light enlarging system "

i have hundreds of rolls and sheets that i developed a little "thinner" because they were enlarged via condenser enlarger and
they are extremely difficult to print with a cold light head because i didn't process them enough. if you are scanning, i would
process your film on the condenser-side of things, too dense and your beam won't be able to replicate what it sees and you will get
an extremely high key image ... ( when it isn't intended to be high key ) ... but then again, maybe that is the look you want?

good luck !
john

Michael R 1974 said:

Depends to some extent on the film and developer, but we'll still have to disagree on this.

Click to expand...

That's fine, as long as I'm right.

I've done a slight amount of testing along these lines... set up a still life, stick a chart or grayscale in it if you have one, light it artificially, shoot a whole roll of the dang thing (even bracket in sets of three, under, proper, and overexposure). Snip off the leader, and snip into 5 or 6 inch strips (in a changing bag). Put the strips in something like a 4x5 film box (light tight) and start putting strips on your reel and trying different processing setups.

For time and temp changes, you can re-use one shot developer several times (since it's intended to handle an entire roll and you're only getting a few frames).

After you wash, make notes based on frame number as to what the variables were. Dry and sleeve the film, and get out your light box and the best loupe you have.

**Sometimes** you'll say "aha, I see the difference". Others... I dunno. Maybe I haven't been examining negs long enough. Getting a pack of cheap RC paper and running some prints may show you a bit more.

Overall, I've learned a bit about shadow detail and highlight density from testing like this... most tellingly, I've dialed in the right ISO for a specific film and the way I shoot. My shadow detail and overall balance improved markedly doing this, and if you settle on a few favorite films, it really is worth the time and a few ML of soup.

And it makes you feel a little badass, like "Honey, I'll be testing my exposure and developing times for a while, please don't disturb me". Ladies be likin' dat talk.