PMK TIMES vs DENSITYgreenspun.com : LUSENET : Large format photography : One Thread
After attending the Smith Chamlee workshop (see review by Sean Yates) I started working with PMK (with Tri X 4x5). Reading Hutchings book his density vs Zone figures seem very high and developing times seem very long vs what I am seeing. For example-he recommends ca 15min (70F) for Tri X (at around 260ASA)-this gave me negatives that have Zone 8 off the printable scale (Grade 2 galerie/Dektol). He also says get Zone 7 density up over 1.5 (see table in back of book)which seems too high (not for Pt I guess). What I am finding is that Tri X rated at 320ASA developed (continuous shuffling agitation in trays at 68F) for about 8 min (water stop, hypo fix)gives printable Zone 8 and 9 (By the way I do not return the negs to the developer bath). Am I missing something in Hutching's book? For those PMK/TriX users out there-are your times/speeds in the same ballpark? Thanks. By the way the tonality/acutance/feel is fantastic-in straight comparison shots vs HC110 the difference is easily visible.
-- Alan Barton (email@example.com), May 20, 2000
Alan, I believe that Hutchings recommends different zone 8 density readings, depending on whether you are using graded or VC paper. If I remeber correctly zone 8 for VC should be about 1.6 and zone 8 for graded paper should be about 1.4. VC paper gives lower contrast in the highlights due to the green stain which is stronger where there is more density. Graded paper does not see this masking effect. Yes you should immerse your negatives in the used developer, it helps to create a stronger stain. I can't help you with times and ASA reatings for TRI X as I use FP4 plus which I like very much with PMK. Good luck Art Nichols
-- Arthur Nichols (Artnichols@syda.org), May 20, 2000.
I process my negs Tri-X negs (EI-260) for NORMAL developement in PMK Pyro for 14 minutes at 68F. N+1 for 20 minutes and N-1 for 11 minutes.
You really do want to return the negatives to either the used developer or a sodium metaborate solution for 2 minutes. This will allow futher stain to build in the highlight areas. Additionally stain will also develop with a 20 minute prolonged wash.
Do not use perma wash or any other hypo clear as it reduces stain.
I find that my negatives print wonderfully well in both silver and platinum.
BTW, how are you measuring your densities? I am sure that you realize that you can not use a visual densitometer with PYRO negs. I use a color densitometer with a blue filter. This provides values that approach those of silver in the shadow areas but the highlites still read with more density than silver.
I make all of my diapositives and internegs with PMK and Rollo Pyro.
Good Luck Mike
-- Mike Kravit (firstname.lastname@example.org), May 21, 2000.
The times you were given for Tri-X in PMK are within the normal range, and are close to what I use for roll film. However, your setup or processing techniques may differ from mine or from Hutchings', so you may require a shorter time or a higher EI or both. The earlier respondent is correct that you should use some sort of alkaline bath after fixing to enable the staining effect of PMK--the stain is one of the primary reasons for using PMK.
-- (email@example.com), May 22, 2000.