Pyro Developer and Thin Negatives

Discussion in 'B&W: Film, Paper, Chemistry' started by Snapshot, Oct 16, 2007.

  1. Snapshot

    Snapshot Member

    Messages:
    914
    Joined:
    Jan 10, 2007
    Location:
    Toronto, Ont
    Shooter:
    Multi Format
    Hi All,

    I've been experimenting with a personal pyro developer fomulation. Fortunately, the negatives appear to have good density, low base fog and excellent sharpness. However, the negatives appear to be nearly as dense as negatives developed with FX-37, which has a tendency to produce dense negatives.

    Would I gain additional benefit if I develop the pyro negatives to be thinner? Should I be developing the pyro negative to be thinner or is this dependent on the type of pyro formulation?

    Any thoughts?
     
  2. TheFlyingCamera

    TheFlyingCamera Membership Council

    Messages:
    9,180
    Joined:
    May 24, 2005
    Location:
    Washington D
    Shooter:
    Large Format
    Print them first and see what you're getting. They may be fine, or they may be dense. Best way to tell is make some prints. If your exposure times double or triple over a non-pyro developer, they may be too dense. I say MAY because you'll need to look at what is happening to your highlights and your shadow details. If your highlights are way blown out, but you have good shadows, then you're overcooking your film. If your shadows are too thin, adjust your exposure (add more) then cut your development time to bring the highlights back down. Many people seem to think the first time they see a pyro neg that it is actually too thin, when in fact the stain makes up for the seeming lack of density, so I'm surprised that you feel your pyro negs are too dense.
     
  3. Tom Hoskinson

    Tom Hoskinson Member

    Messages:
    3,879
    Joined:
    Mar 7, 2004
    Location:
    Southern Cal
    Shooter:
    Multi Format
    The printing density of negatives developed in any staining developer (Pyrogallol, Pyrocatechol, Hydroquinone, Amidol, etc., etc.) is virtually impossible to evaluate by eyeball. You need to print the negs or run them through a transmission densitometer - or both. Depending on your printing process, the color of the stain can be important and stain color is determined by the formulation.
     
  4. jim appleyard

    jim appleyard Member

    Messages:
    2,121
    Joined:
    Nov 21, 2004
    Shooter:
    Multi Format
    I agree with the above. In fact, Gordon Hutchings, author of the "book of Pyro" and inventor of PMK developer, has said that pyro developed negs will look impossible to print and that you need to actually make prints to evaluate them.
     
  5. Snapshot

    Snapshot Member

    Messages:
    914
    Joined:
    Jan 10, 2007
    Location:
    Toronto, Ont
    Shooter:
    Multi Format
    Well, it would seem some prints are in order before adjusting my development time. I asked the question is because I was expecting thinner negatives but instead I had negatives that appeared to being nearly as dense as negatives developed in FX-37.
     
  6. Tom Hoskinson

    Tom Hoskinson Member

    Messages:
    3,879
    Joined:
    Mar 7, 2004
    Location:
    Southern Cal
    Shooter:
    Multi Format
    Why were you expecting thinner negatives?

    What developer are you using? What dilution and development time? Which agitation scheme ?
     
  7. Snapshot

    Snapshot Member

    Messages:
    914
    Joined:
    Jan 10, 2007
    Location:
    Toronto, Ont
    Shooter:
    Multi Format
    I was expecting thinner negatives due to numerous reports that pyro developers, such as PMK, produce thinner negatives. I was using a custom formulation, consisting of Metol, HQ and Pyro. Approximately, 1.7g of developer was used in a litre of solution. TEA was used as the alkali/accelerator. The dilution ratio was 1+100 (1 part developer concentrate and 100 parts water). I developed APX 100 for 10 minutes using a 30 second initial agitation, and 10 seconds of agitation every minute.

    My hope was to get a sharp pyro based developer. Since I liked the PC-TEA and 510-Pyro concentrates, I experimented with a new developer formulation. I was very satisfied with the sharpness and detail rendition but I considered the negatives to be too dense to be typical. Perhaps, I'm worried about nothing.
     
    Last edited by a moderator: Oct 16, 2007
  8. sanking

    sanking Restricted Access

    Messages:
    4,813
    Joined:
    Mar 26, 2003
    Location:
    Greenville,
    Shooter:
    Large Format

    I develop most of my negatives in either Pyrocat-HD or Pyrocat-MC. In terms of density they do not look visually much different from negatives developed in non-staining developers.

    All of the Pyro staining developers I have used, including PMK, Pyrocat-HD and -MD, and WD2D, are acutance developers when developed with normal agitation, and high acutance developers when developed with minimal agitation.

    In your Pyro formula, what is the role of the HQ? My thought is that HQ requires such a high pH for threshold activity that it would not be activated by the pH of TEA?

    Sandy King
     
  9. Snapshot

    Snapshot Member

    Messages:
    914
    Joined:
    Jan 10, 2007
    Location:
    Toronto, Ont
    Shooter:
    Multi Format
    Hi Sandy,

    I have a pH value close to 10 for the formula (estimated from test strips as I don't have a digital meter yet). I was surprised at the 'relatively' high pH but that's what the test strips indicated at 1+100 dilution. The HQ was to bump up the contrast a bit. It's my understanding that pyro-metol formulas tend to be of moderate contrast. Since I use VC paper and the pyro stain acts a contrast mask, I wanted a little more contrast to compensate.

    The formulation that I used is as follows...

    TEA...............100ml
    Metol.............2.0g
    Hydroquinone...5.0g
    Pyrogallol........10.g
     
  10. sanking

    sanking Restricted Access

    Messages:
    4,813
    Joined:
    Mar 26, 2003
    Location:
    Greenville,
    Shooter:
    Large Format

    A pH of 10 is much higher than I would have expected from TEA at this dilution. I have an electronic pH meter and would get no more than about pH 9.2 with this dilution.

    However, there could be significant synergism between the three reducers that activates the hydroquinone at a lower pH?

    But why HQ and not ascorbic as the third reducer? Were you concerned that there would be a loss of sharpness as Hutchings suggests with Pyrogallol + ascorbic?

    Sandy
     
  11. gainer

    gainer Subscriber

    Messages:
    3,726
    Joined:
    Sep 20, 2002
    Contrast of pyro negatives.

    Where did the myth arise that you cannot use printing filters with pyro negatives on VC paper? If you have a yellow, orange or red stained negative where the stain is proportional to the silver image, you could in fact use a blue separation filter to get the same printed image you would get from blue sensitive graded paper. The stain of a pyro or pyrocatechol negative would have to be inversely proportional to the silver image to get a reduction of contrast, or else the blue sensitive emulsion of the paper would have to be the low contrast emulsion. You don't have to believe me. You can prove it for yourself.
     
  12. Snapshot

    Snapshot Member

    Messages:
    914
    Joined:
    Jan 10, 2007
    Location:
    Toronto, Ont
    Shooter:
    Multi Format
    Ahh... it seems I'm operating under a mistaken belief. I thought that contrast filters would not be as effective for pyro negatives.
     
  13. gainer

    gainer Subscriber

    Messages:
    3,726
    Joined:
    Sep 20, 2002
    BTW, the less pure grade of TEA could give considerably higher pH than the best grade because it contains as much as 15% diethanolamine. (I wonder why I never see it as DIE for short?)
     
  14. Snapshot

    Snapshot Member

    Messages:
    914
    Joined:
    Jan 10, 2007
    Location:
    Toronto, Ont
    Shooter:
    Multi Format
    I avoided ascorbic acid because I've had difficulty obtaining a source that was reliable in quality. It seems that the quality/content of store bought ascorbic acid varies. I suspect that what ascorbic acid I did purchase contained dehydroascorbic acid, which isn't effective as a developer but acts like ascorbic acid in the body. This affected the development qualities of the formulas I used.
     
  15. gainer

    gainer Subscriber

    Messages:
    3,726
    Joined:
    Sep 20, 2002
    Erythorbic acid is the isomer of ascorbic acid, its mirror image, that developers can use but the body cannot. I got it from KICgroup. You can get ascorbic acid from The Chemistry Store or from NOW foods. Usually, the label tells whether the drug store vitamin C is ascorbic acid, dehydroascorbic acid, sodium or calcium ascorbate (may be labelled "Ester C".
     
  16. Snapshot

    Snapshot Member

    Messages:
    914
    Joined:
    Jan 10, 2007
    Location:
    Toronto, Ont
    Shooter:
    Multi Format
    Following the advice of TheFlyingCamera, it printed some negative frames. What I found was blown highlights but acceptable shadow detail. So, it would appear my answer is that the negatives are too dense, as my printing time was extended as well. I'd like to thank everyone for their contribution.
     
  17. TheFlyingCamera

    TheFlyingCamera Membership Council

    Messages:
    9,180
    Joined:
    May 24, 2005
    Location:
    Washington D
    Shooter:
    Large Format
    Sounds like a second test is in order, using the same exposure settings, but cutting your dev time by about 15-20%. See if that works for you, and if your highlights are still blown out, maybe it's time to adjust the chemistry.
     
  18. Snapshot

    Snapshot Member

    Messages:
    914
    Joined:
    Jan 10, 2007
    Location:
    Toronto, Ont
    Shooter:
    Multi Format
    I'll give it a try today (time permitting). I reshot some scenes this morning so a near direct comparison is feasible.
     
  19. Snapshot

    Snapshot Member

    Messages:
    914
    Joined:
    Jan 10, 2007
    Location:
    Toronto, Ont
    Shooter:
    Multi Format
    Well, I cut processing time by 30% and it appears to be resolving the issues I've been having. There are deep blacks, shadow detail and highlights that aren't blown. I'm getting near the appropriate developing times but I may even cut it down even more. Right now, I'm souping APX 100 (at EI 100) for 7 minutes using a 1+100 dilution, which seems very quick. Grain has reduced so that it is very comparable to the results I've seen with FX-37, with at least equal sharpness.
     
  20. Tom Hoskinson

    Tom Hoskinson Member

    Messages:
    3,879
    Joined:
    Mar 7, 2004
    Location:
    Southern Cal
    Shooter:
    Multi Format
    If that approach does not work out for you, try replacing the Hydroquinone with Ascorbic Acid and the Pyrogallol with Catechol.

    However, it would probably be easier to just mix some Pyrocat (either HD or MC). Pyrocat is great at clamping the highlights.
     
  21. Snapshot

    Snapshot Member

    Messages:
    914
    Joined:
    Jan 10, 2007
    Location:
    Toronto, Ont
    Shooter:
    Multi Format
    Well, it would make my life easier to use and existing formulation. However, I do have some pyrogallol that needs to be used up first.
     
  22. gainer

    gainer Subscriber

    Messages:
    3,726
    Joined:
    Sep 20, 2002
    You can use pyrogallol in place of the catechol in Pyrocat MC, PC or HD. Pyrogallol has a heavier molecule but it also has an extra OH group, it being trihydroxybenzene instead of dihydroxybenzene. Each molecule is about 33% more active than a molecule of catechol, but weighs about 1.15 time as much, so you would use 75% as much of the pyro as of the catechol. If you would like to mix the A solution in glycol, use a small amount of ascorbic acid instead of sodium sulfite.
     
  23. Snapshot

    Snapshot Member

    Messages:
    914
    Joined:
    Jan 10, 2007
    Location:
    Toronto, Ont
    Shooter:
    Multi Format
    This is great news. Thank you for providing me with the chemical information. I'll give one of the Pyrocat formulations a whirl.