that's the original idea...BUT...if paper developer already does it out of the box, then why bother, right?
Originally Posted by StoneNYC
Can you measure the approximate pH of film and paper developer working solutions? It may be that at high pH HQ in paper developers is activated to preferentially develop more exposed areas of film,not the fog.
Originally Posted by johnielvis
right--now there's another thing---so this can be happening too then..hc-110 is apparenlty not pq but but is HAS been recommended as a paper developer or a universal developer--this may not actually be the case then--just because it CAN developer paper does not mean it does so as good as paper developers.
Originally Posted by Alan Johnson
NOW the question: would the PQ developer have the same preferential development effect with film or are the film grains too small for it to matter?
The weekend may give time to see if there's a visual difference in reversal processing of film--speed changes...dmax changed, etc. time for another "let's see what happens"....
If you want to know how developer works on film, then you need to test it on film rather than paper. Paper is very different in many ways.
I don't think you mentioned what paper developer you used. The most common paper developer is Dektol which is based on the Kodak D-72 formula (many other developers in the past were nearly the same composition). D-72 was a developer for film and paper. It was very commonly used for film processing in early press and other photography. Walker Evans used it for many of his 8x10 negatives. I used it a great deal for Cirkut negatives. What we consider paper developer is not always something that was originally intended for only paper, so the distinction is somewhat artificial.
Because there were other developing issues mentioned about using paper developer such as needing a more aggressive agitation technique etc. that might dislodge the film especially if it's old and curly or thin base, and why change your developing techniques if you can just add some chemical to a developer that already works well. Plus personally I don't optically print (for location reasons not because I don't like optical printing) so to buy a bottle of paper developer JUST for a few old rolls of film seems a waste to me.
Originally Posted by johnielvis
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Results of my test of 10 year old HP5+ (storage unknown) in film developer Rodinal 1:50 16m 20C and print developer Ilford ID-62 1+7 8m 20C.
The first attachment shows the fog levels by photographing the developed films on a light box.There is little difference, 10 years old film did not give a significant problem.
From prints, there is little difference in grain either.
I like the more contrasty print developer as giving a more "fine art" look, second attachment,it may be coincidence.
So IMO HC110 probably is the best for low fog combined with finer grain,better than these two developers.
hc-110 appears to be mucho mucho more powerful than the ilford paper developer--maybe that's why it was so hot acting with the paper.....
results of FILM (txp-320--fresh film) experiments recent:
there is definite speed loss with the ilford pq universal paper dev vs hc-110....a very WEIRD thing just happened...the last test done was STRAIGHT ilford pq universal concentrate liquid--no dilution...and it actually developed the image WAY LESS than the concetrate cut 1:1......the experiment set was started with the recommended dilution of 1:9 which came out dark...then to 1:1 which came out about 1 or so stops darker than hc110....then when no dilution was used, the results were way darker...like darker than the 1:9 dilution....either water has some superaddative effect or something went wrong...this last straight soluion test will be repeated....
preliminary results are that hc-110 is much much more strong than pq universal...apparently it isn't ph that drives this since the straigt pq uinversal concentrate would have a stronger base but it developed LESS than when cut with water.
either that or PQ needs water to work where hc110 needs less water?....first a re-do of the straight concentrate test.....
bottom line...based on the results so far--it appears that the hc110 used was much stronger than the ilford pq universal paper develoer--even at full strength concentrate.
Last edited by johnielvis; 01-09-2013 at 10:44 PM. Click to view previous post history.
A possible explanation of your result is that HC-110 is more active because the organic amines make HQ active at pH 8.8-9.0 compared to typical print developer pH 11-12.Likely HC-110 will give finer grain.
If there are any results for fog levels with film in the two types of developer that would be interesting as well.
the "straight concentrate" pq universal "retest" showed SAME results as original....way dark--meaning way less first development than diluted pq-universal.....the "more first development with more concentrated mixture" curve just dumped...the last "good" concentration that showed "improvement" was at 1:1...so next it will be 2:1 developer to water and run it one more time and see what happens...apparently water dilution is needed for this stuff to get up to speed....
THEN AGAIN...perhaps this is the result of FOGGING...the darker transparencies lack contrast...so you are right apparently, mr alan johnson--the more concentrated stuff is fogging a bit..or otherwise reducing contrast, but diabolically, at the same time, somehow preventing density from building up as much as more diluted solutions. nothing's easy
the hc-110, of course is a totally different animal, that stuff just gets stronger and stronger with more concentrated solutions....it's not pq but other stuff which nobody knows for sure what EXACTLY it is...more when it comes...
RIGHT...re-did the experiment with the PQ universal liquid concentrate--SAME RESULTS--much less first development than the diluted concentrate.
Last test was with a 2 parts concentrate : 1 part water...THIS gave WEAKER results than the 1:1 dilution--close but noticibly less development.
It appears that this stuff must be diluted with water for it to become "activated" properly. Interesting. It appears that 1:1 dilution is the limiting factor for developer strength--any less dilution and you get less development.
It appears the source of the paper developing fog when hc110 was used was that the much much stronger hc110 developer overpowering the paper and bringing out fog where there was none otherwise...the developer was too "hot".
Last edited by johnielvis; 01-11-2013 at 06:54 PM. Click to view previous post history.