Noob meets Development Speed

Up til now, with the aid of the Mass Dev Chart, I've developed Tri-X 400 at just that- 400 speed
for 7 minutes in D-76.

Simple enough.

Here's what I'm not understanding:

I'd now like to learn developing Tri-X in Acufine as I like the results it seems to give. However,
as I look around the internet and see people's Tri-X w/Acufine developing experiences, I see
that Tri-X in Acufine should be developed somewhere between 1000 and 1600EI (give or take).

I don't understand this basic principle that many others seem to fully understand.

Does this mean to shoot the Tri-X 400 at 400iso and to then lengthen the develop-
ment times to a point as if the film had actually been shot between 1000 and 1600iso?

Or, does this mean that I should shoot the Tri-X 400 between 1000 and 1600iso
and then develop it at a length of time appropriate for 400iso?

Or, does this mean that I should shoot the Tri-X 400 between 1000 and 1600iso
and then develop it at a length of time appropriate for 1000 to 1600iso?

Or something completely different.

Thanks kindly in advance.

Acufine / Diafine is a bit of a weird one, it's a twobath developer where it soaks up the first bath proportionately to exposure, then gets developed in the second bath proportionately to how much it's soaked up.
Or something like that.
Either way, times for *fine are near enough to the same for every film, you can't 'push' or 'pull' by extending or decreasing times like a regular developer.
So in short it means you set your meter to ei1600, shoot accordingly, then use the times as written.

Dr. C, Thank you for your response. I just haven't been able to grasp whether the


camera or the developing did the heavy lifting. Thanks once again!

Exposure controls shadow detail. Development controls highlight density with little effect on shadow density. This has the effect of controlling printing contrast.

The one that it took ages to get my head around is when people say 'speed increasing' and 'speed reducing' developers.
eg for FP4, its 'speed' in most developers is 125, its 'speed' in perceptol is 64, and in microphen it's 200 (or near enough).
What that means is that to produce a negative of the same contrast, set the meter to that ei then use the times as written.
From there you can push or pull by in/decreasing times. eg to shoot FP4 at ei125 and dev in perceptol, you're actually pushing it a stop and increasing contrast, or to dev in microphen you're pulling it down a stop and decreasing contrast.

In short, just follow the recommended ei and times on datasheets or the MDC and you'll be fine to start with.

When you're comfortable later, start experimenting with pushing/pulling, and all that associated latitude expansion/compression that you get from the Zone System..

wow

You say you developed ISO 400 Tri-X to get an ISO of 400. Amazing. I thought that idea went out with running boards on cars and Royal typewriters. I like Tri-X at 400 and have being developing it for that speed ever since I couldn't get Super Double X film from Kodak anymore. Don't let the Acufine/Diafine folks confuse you. They are in another space capsule some light years on the other side of Mars. I like Acufine and Diafine but find the Urban Myths about these products to be fantastic. Stick to what works for you. Later you can join the others seeking the Treasures of the Indies in the form of a hot new developer. Good luck.

Acufine and Diafine do something different with film contrast. In essence, they give you less, unless you increase the development. The suggested times for them incorporate that increase.

When you expose films at the EIs suggested for Acufine and Diafine, and follow the development recommendations accompanying those developers, some films give better shadow detail when developed in Acufine and Diafine than when you develop those films in standard developers. That translates into something similar to increased light sensitivity.

In essence, Acufine and Diafine make some under-exposed films look and print better in some circumstances. They do so with a cost though - they can give really flat results sometimes.

"Exposure controls shadow detail. Development controls highlight density with little effect on shadow density. This has the effect of controlling printing contrast".


ic-racer: Roger that. Am curious how Acufine will handle a defunct drive-in movie screen recently found in my area.


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"The one that it took ages to get my head around is when people say 'speed increasing' and 'speed reducing' developers.
eg for FP4, its 'speed' in most developers is 125, its 'speed' in perceptol is 64, and in microphen it's 200 (or near enough).
What that means is that to produce a negative of the same contrast, set the meter to that ei then use the times as written.
From there you can push or pull by in/decreasing times. eg to shoot FP4 at ei125 and dev in perceptol, you're actually pushing it a stop and increasing contrast, or to dev in microphen you're pulling it down a stop and decreasing contrast."


Dr. C.: Thank you for the task!


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"You say you developed ISO 400 Tri-X to get an ISO of 400. Amazing. I thought that idea went out with running boards on cars and Royal typewriters. I like Tri-X at 400 and have being developing it for that speed ever since I couldn't get Super Double X film from Kodak anymore. Don't let the Acufine/Diafine folks confuse you. They are in another space capsule some light years on the other side of Mars. I like Acufine and Diafine but find the Urban Myths about these products to be fantastic. Stick to what works for you. Later you can join the others seeking the Treasures of the Indies in the form of a hot new developer. Good luck".


snapguy: Yes, Tri-X 400 in school is actually where I left off in 1983 when I put developing away for (gulp!) 31 years. Fell right into it again as a somewhat known quantity when I started developing again this past Spring.


But more to the point, after the last six-months, I'm comfortable now with what I can consistently do with Tri-X at 400. Am seeing that Acufine can give Tri-X a nice glow and I'm curious to investigate. Your advisement is well taken. Just pushing things a little to see what might shake out. My "400 Zone" remains there to return to!


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"Acufine and Diafine do something different with film contrast. In essence, they give you less, unless you increase the development. The suggested times for them incorporate that increase".


Matt: Roger this.


"When you expose films at the EIs suggested for Acufine and Diafine, and follow the development recommendations accompanying those developers, some films give better shadow detail when developed in Acufine and Diafine than when you develop those films in standard developers. That translates into something similar to increased light sensitivity.


In essence, Acufine and Diafine make some under-exposed films look and print better in some circumstances. They do so with a cost though - they can give really flat results sometimes".


Matt: Yes, the thread here of "some films" and "some circumstances" is understood as part of the learning. This has been forefront when considering trying Tri-X with Acufine. I've read enough discussion and viewed enough examples of this combination to believe that the two are a valid match worthy of investigation.




Thank you to all for your input on this question.

pushing is just web gossip if you want a normal print
FP4+ in Microphen 125 maybe
FP4+ in ID11 (or D76) 100 maybe
better to use 50 or 64 if you want a good print