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Old 5th November 2013, 12:45 PM
KeithM KeithM is offline
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Default Acros 100 @ ISO 200 - MassiveDev Chart Error?

Looking at the Massive Dev chart for Acros 100 rated ISO 200 (why I have rated it at 200 is another story...) and developing in Rodinal, it shows a 1+25 dilution and a time of 14 minutes. Normally I use Acros 100 @ ISO 80 and dev 1+50 for 11mins 30secs. Therefore using a twice as strong solution plus a 20% increase in time seems extreme.

Also, the time for ISO 200 compared with 100 & 400 @ 1+25 in the chart seems completely out of line:-

Neopan 100 Acros Rodinal 1+25 ISO125 6.75mins 20C
Neopan 100 Acros Rodinal 1+25 ISO200 14mins 20C
Neopan 100 Acros Rodinal 1+25 ISO400 7.75mins

Thoughts?
(Have emailed Digital Truth about the seeming anomaly).
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Old 5th November 2013, 04:02 PM
John King John King is offline
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Default Massive dev chart

But is it an error? Have you processed a film at what they suggest and if so what did you get?

There are more errors with the Ilford timings which they give in the inside of the film boxes. Don't ask me how I know!!!!!! The nice guy at Ilford stated that this has come about because millions of boxes are printed each year and not all of them get used before the film changes slightly so there will be inaccuracies, and advise always to go to their website.
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Old 5th November 2013, 08:52 PM
Mike O'Pray Mike O'Pray is offline
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Well it certainly looks very strange when ISO 400( at least a two stop push) needs less time than a one stop push.

I'd be interested in any explanation DigitalTruth come up with. The times as I understand it are those submitted by users. I suppose that this might be one user only and he/she has got it seriously wrong and/or the 200 user like seriously "thick" negs

I wonder what Rodinal has to say about times and Acros 100?

Mike
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Old 5th November 2013, 09:16 PM
Lostlabours Lostlabours is offline
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The Chart is only a rough guide, much of it comes from contributions rather than manufacturers data.

There's some gross anomalies, times for rotary processing get passed of as being for inversion agitation, temperatures/times are erratic (some thermometers may be well off being accurate).

Agfa's own data sheet for Rodinal was remarkably good and their dev times and recommended EI's spot on both for their own films and competitors.

Ian
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Old 7th November 2013, 03:16 PM
KeithM KeithM is offline
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The prompt response from the Massive Dev people:-

Quote:
Thanks for pointing this out.


All three times listed for Acros in Rodinal 1+25 are user submissions. After studying the other data available I have removed the 14 min at 200 ISO time from the online chart and it will be removed from the app at the next update (currently planned for January). All of the users who submitted these times have a good track record of providing reliable data, so my belief is that the 14 minute time is probably suitable for low contrast scenes as it is possible to develop Acros for very different amounts of time and produce good results depending on subject contrast. However, I removed the time because it would be misleading for most situations and the other data clearly presents more accurate general purpose starting points.


Many thanks,


--Jon Mided


Managing Director
Digitaltruth Photo Ltd

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