If you use a different process or different developer than the factory, that doesn't magically change the ISO speed of the film. The film's speed is the same. I just don't understand the logic of people who think that the film's speed is changing when their metering or processing is changing. No, the film's speed isn't going anywhere; your metering and processing are. /QUOTE]
Unfortunately it does, the choice & balance of developing agents is extremely critical.
So a developer like Perceptol/Microdol-X cuts film speed by a stop, but a Phenidone/Hydroquinone developer like ID-68/Microphen increases speed by over half a stop.
Some super fine grain developers can reduce speed by 2-4 stops, needless to say they have gone out of use
Ian
So a developer like Perceptol/Microdol-X cuts film speed by a stop
If you use a different process or different developer than the factory, that doesn't magically change the ISO speed of the film. The film's speed is the same. I just don't understand the logic of people who think that the film's speed is changing when their metering or processing is changing. No, the film's speed isn't going anywhere; your metering and processing are. ...
... On the other side of the coin, I don't understand the value of knowing the film's exact speed, because all that matters is your results. ...
... But if you ever want to know what it is, it's printed on the box. ...
... I don't understand the advantage of re-rating the film speed, as if the film manufacturer does a poor job at it. ...
I don't see it that way. Perceptol/Microdol-X may put 1 stop less density on the film than D76, but I don't see how that changed the film's speed. All it means is that you need to expose 1 stop more if you are using Perceptol. If you had developed it in D76 instead, it would have more shadow density...see, the speed didn't change.
I know that if I expose a certain way, I will get probably a good stop more shadow density out of Tri-X if I develop it in Xtol than if I develop it in D23, but I don't think that developing in D23 somehow changes the film speed. Tri-X is an ISO 400 speed film, in any developer you use, period, if you believe Kodak (and there's no reason to doubt them). That's the point of standards.
If you use a different process or different developer than the factory, that doesn't magically change the ISO speed of the film. The film's speed is the same. I just don't understand the logic of people who think that the film's speed is changing when their metering or processing is changing. No, the film's speed isn't going anywhere; your metering and processing are.
On the other side of the coin, I don't understand the value of knowing the film's exact speed, because all that matters is your results. But if you ever want to know what it is, it's printed on the box. I don't understand the advantage of re-rating the film speed, as if the film manufacturer does a poor job at it. But then, I don't really use light meters either, so maybe I should leave the film-testers and densitometrists alone to do their thing.
What does "better tonality" mean?
Tonality is defined as 'the range of tones'. Giving more exposure and reducing development will increase the range of usable tones, and hence, increase tonality. I guess, you could call that 'better tonality'.
I don't see it that way. Perceptol/Microdol-X may put 1 stop less density on the film than D76, but I don't see how that changed the film's speed. All it means is that you need to expose 1 stop more if you are using Perceptol. It doesn't mean the film speed magically changed. A film's speed is a property of its manufacture.
I think what BetterSense is saying is that it isn't the film's "speed" that is changing, it is the "speed" of your procedure and process when using that film.
The film is the constant - the rest changes with circumstances.
It would probably be best for me (as an example) to talk about "Plus-X in exposed moderate contrast light developed in HC110 dil "E" with rotary development after a 3 minute pre-soak and printed using a diffusion light source" speed.
But I am wordy enough as it is.
That's technically correct, Ralph, but since this is all very subjective, "better" may not be applicable. Giving more exposure and increasing development decreases the range of tones but that doesn't make them any less usable. Different, yes, but certainly not less usable. Again, taking Ralph Gibson as an example, one would have to say that his work is not about "better tonality" but HIS approach worked successfully nonetheless. There something to be said about a bold image that falls outside the norm to be interesting versus one that is 100% "correct" but falls flat on its face.
Best,
Max
I think what BetterSense is saying is that it isn't the film's "speed" that is changing, it is the "speed" of your procedure and process when using that film.
The film is the constant - the rest changes with circumstances. ...
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