paper developer vs. high contrast film developer
results of experimentation with paper direct reversals show that film developer used on paper develop fog where paper developer does not.
Now--this being the case--would the paper developer also develop less fog on regular film, or is film different from paper in the fog-wise sense so that it is much less sensitive to fog?
it would appear that all thing being equal, paper deveoper will be able to develop older film say or do reversal with more detail/dmax....
any ideas on this anyone? experiences? whys and wherefores?
I suspect paper developer is formulated to develop....paper. Film is a different aminal. You're planting tomatoes and expecting onions. You can try different paper developers, different developer dilutions to see if you can get something better/different.
Let me re-phrase the question:
Would the extra restrainers used in paper developer have any beneficial effects in developing film "to completion" ala reversal processing OR is film just naturally more resistant to developer action due to finer grains and the extra restrainer does nothing SIGNIFICANT RE fog reduction?
Remember SIGNIFICANT...of course it does something, but it may not be significant and that is the suspician here--since this has probably been investigated before, in order to save time experimenting, what are the facts here?
Your mistaking fog with under-development in the first developer, you need a more vigourouse developer for reversal processing anyway. Few film developers will process paper to a high enough Dmax.
I use paper developer with long expired films with known high base fog. Generous (over)exposure and 2-2:30mins in paper developer, usually Orwo N113.
Originally Posted by johnielvis
The grain and contrast will be higher than with film developers, tho it is not the problem with 120 and up formats.
Dec 1965 expired 120 Perutz P17, shot at EI25, developed in paper developer. Rodinal gives me only mush with high fog with this film.
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The first developers used in reversal film processing are quite similar to paper developers.
you don't understand. using hc-110 dil a to develop paper resulted in fog or other developing unexposed in under a minute. Using paper developer on the same paper at the same time, same "exposure" (no exposure at all) this resulted in no such "fog" developing after over 2 minutes. This means that the paper develop has some extra restrainers in it. This was not "underdevelopment" since the same was done with exposed papers and the paper developer developed an image where the hc110 developed the image plus fog and kept getting darker and darker and darker as time went on.
Originally Posted by Ian Grant
The conclusion is extra restrainers in the paper developer work to keep the "fog" from developing but still can develop the high densities needed in a similar amount of time.
Now the question is: if this is due to restrainers doing their job properly, then is there something more hypersensitive in paper--bigger grains or something--that makes it more sensitive to developers where film would be insensiive due to smaller grain structure? Is this what is going on? if that is the case then film developer could be designed "hotter"...as it apparently is...
YES--this is what I"m getting at---paper developer seems to be more forgiving of fog due to time or heat yet still allows high contrast development to save the image--film developer--apparently "hotter" would cause more fog to develop then, right? This is due to restrainers, correct? and therefore this WOULD give better dmax in reversal processing of film since it inhibits fog development--or at least will allow reversal processing of older films that have agefog that would otherwise lose dmax.....
Originally Posted by werra
this seems to be the case--so you've noticed this and are exploiting it--good!...that's like a confirmation then....any OTHER experiences folks?
Some of the chemistry is discussed in this thread:
My summary (it may not be completely right):
HQ selectively develops the more exposed areas as its semiquinone oxidation products are also developers, possibly this would imply that the fog is developed less.Organic amines make HQ active at pH 8.8-9, lower than the pH required without them.At higher pH than 10 benzotriazole is the preferred restrainer with PQ developer.
I have a couple of old films (10 yrs) to develop, will make up some Ilford ID-62 universal developer and try that. In absence of organic amines use of carbonate gives high pH and some benzotriazole is preferred.
that link is a long detective tale--that is true...apples and apples were not compared--the hc110 was up against PQ universal ilford paper developer--paper strength concentration....but it does seem strange that low fog on film gives very significant fog on paper...or just outright develops stuff that is not fogged or otherwise exposed--like a fogging developer type behaviour.