forgive this newbie question

I'm using the Massive Dev app for processing film and, with a particular film and developer combo it will list a variety of options. For example Efke 100 with D76 lists: Stock , 1+1, 1+3. I'm assuming the stock mean the basic concentration as on the packaging instructions and the others mean one part stock to two one part water, one part stock to three part water. The more diluted formulas require longer development times. Is this all correct so far?

But why? what are the reasons for using more diluted formulas. What is accomplished by diluting the formulas and extending the development times?

Incidentally, I think the Massive Dev App is completely amazing. :cool2:

The answer is complex, having to do with the various chemicals that have solvent action versus acceptance action, and how their contribution to the image changes with different dilutions. You should get Anchell's books. In particular, you can get the Film Developer's Cookbook vol 2 as an e-book from Amazon. Highly recommended if you are doing your own development, and overall a fascinating read.


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I am here: http://maps.google.com/maps?ll=40.029204,116.510911

Oh and I should add, if it wasn't clear: changing the dilution will affect sharpness, acutance, tonality, etc. in useful ways, depending on what you want out of your image. Get the book, and also web search on the various dilutions. A lot has been written online.


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I am here: http://maps.google.com/maps?ll=40.029275,116.511006

Thanks for the response. But to be sure, I was correct in the whole 1+1 an 1+3 thing?

I've added the book to my amazon cart. Think I'll go for the paper over kindle.

Brian

APUG has an enormous amount of info on the effects of developer dilution. A search over there should give you days worth of reading material.

Your assumptions are correct, except one minor point that is really just a matter of the precision of your wording, not a gross conceptual error. "Stock" simply means undiluted. It doesn't necessarily mean what the packaging says to use on the film, because often times the package itself will call for diluting the stock as a standard practice. For example, Kodak HC-110. The stock is almost never used directly on the film...but it is still called "stock."

2F/2F makes an important point, especially with regard to HC-110 (and also Rodinal). I can't imagine an application for using either right from the bottle, they are very concentrated. HC-110 is a thick syrup, designed to be heavily mixed with water before use. (It was originally targeted at commercial shops that use large batches of it.) For both HC-110 and Rodinal, I take a few milliliters and dilute heavily with water (check out the Kodak HC-110 Developer - Unofficial Resource Page for a great, great resource on mixing and using that developer). The cult of Rodinal (I've got the tattoo) has information plastered all over the web.

By the way, my previous post used the word "acceptance" when I meant "acutance". That was an iPad auto spell correction error that I missed.

Regarding your 1+1 and 1+3 assumptions, it is simple, but in the ballpark. But note that when you dilute you are usually seeking different effects (compression, increased acutance, etc.) so you might also be altering your agitation times and patterns. With extreme dilution (like Rodinal 1+100), you might let it just sit for 1/2 hour between agitations, and your agitations might be very, very gentle. You might process for 2 hours or more.

On the other hand, I frequently use hc-110 and dilution "H", which is twice the dilution of dilution "B", just to lengthen my development time. I find the length of time at dilution "B" to be a little to short for my workflow, which involves lots of sloth and laziness.