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Dev chart efke100/acutol typo?
Posted: Sun Apr 17, 2005 3:57 pm
I have a question about developing Efke 100 in acutol. The film I have is exposed after iso 200 so I'll have to push it one step. The issue that concerns me is some figures in the dev chart.
For normal development it says I should develop for 9 min in a 1+9 dillution, but for 200 it says 9 min with a 1+10 dillution. This doesn't make sence to me, if it's more dilluted I should have more time, and also since it needs more contrast because of the push I would also have to use a longer time. Is this a typo or have I not understood the compensating effect of acutol?
Could someone please clear this out before I go ahead and develop the film.
Posted: Tue Apr 19, 2005 1:45 pm
The current recommended dilution for Actol is 1+9, so your best best is to use this data as your starting point.
Paterson originally specified dilutions of 1+10, 1+20 and 1+30 for Acutol, but at some point (late 1990s?) this was changed to 1+9. I don't know the reason for the change, but it may have been nothing more than a desire to come into line with other common developer dilutions. 1+9 is also easier to calculate and the difference to the 1+10 solution would not have been hugely signficant.
Around the same time, Efke changed the film base for its products, resulting in new development data being released.
You may wonder why the older data has been retained in the chart. The reason is that no one has ever reported this data to be invalid, and as much as anyone might presume the most recent data to be the most accurate, this is not necessarily the case. Different testing procedures, or different standards applied to the results (target DMax), may well mean that the older times will continue to work well and may produce some results which are more desirable than the newer times.
What one person considers to be a "good" negative is often too contrasty and has too much density, so it all depends on what you are looking for. Personally, my guess (its just a guess) is that the 1+10 time for 200 ASA will work well, but if I were you I would hedge my bets on the first roll and use the "standard" 1+9 dilution for about 10 minutes. From there you should be able to figure out the time which most suits your work.
Please let me know how it goes as I would like to rationalize this data, its just that right now there isn't enough information to be able to elminate or recommend one time over another.