Support our Sponsors, they keep FADU free:   AG Photographic   Keyphoto   The Imaging Warehouse   Process Supplies   RH Designs   RK Photo   Second-hand Darkroom Supplies   Silverprint Ltd

Notices

Go Back   Film and Darkroom User > Monochrome Work > Monochrome Film

  ***   Click here for the FADU 2015/2014 Yearbooks   ***

Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 10th March 2011, 01:24 PM
Vania Vania is offline
Friend
 
Join Date: Sep 2010
Posts: 10
Question Strange "comet shape" over-developed streak with prescysol... any idea?

Hello,

I've been using Peter Hogan's Prescysol, semi-stand method, for a while now, and with much satisfaction since I switch from filtered water to demineralized water.
But coming back from a photo trip, my first 2 rolls of 120 films gave me weird overdeveloped streaks in the highlights (namely sky area) on some frames. Quite fortunately, the good ones have been spared! Nonetheless, this is quite important work to me, and I can't afford to take any risks with the rest of my film batch.
So I need to figure out precisely what is causing this, and if I can safely keep using Prescysol (which I was really counting on) for the rest of the job.

The film is tri-x. I use the standard semi-stand process @ 24C for 10'30 with a 5 min presoak.
I rinse for 2 min in running water (I change the water 3 times with about 6 to 8 inversion each time).
I always use the same fixer with Prescysol, Berfix 2, made by Bergger specifically for pyro development, and fix for 5 min. I reuse the fixer only once (which was the case here) and add 1 min. Fixer is diluted in demineralized water.
Final rinse is 20 min, then I leave the film for 5 min in demineralized water so I don't need to use a wetting agent.

Any help trying to understand what is going on would be much appreciated, as I am totally clueless... (hope Peter Hogan is around!)
Following are some scans of the problem at hand.

Thank you all for your help.
Vania


Reply With Quote
  #2  
Old 10th March 2011, 08:46 PM
JimW JimW is offline
Friend
 
Join Date: Aug 2009
Location: Worcestershire
Posts: 832
Default

That's a significant highlight in the top of the 'comet' as if one photographed a balloon with flash..... Do all the other 'comets' look similar?
Reply With Quote
  #3  
Old 11th March 2011, 08:01 AM
Peter Hogan's Avatar
Peter Hogan Peter Hogan is offline
Friend
 
Join Date: Sep 2008
Location: Buckinghamshire
Posts: 504
Default

I've spent some time examining these negs, and I can't think of any processing problem whatsoever that would result in such identical marks repeated like this. I've never seen this with any developer, let alone Prescysol! I would say it is almost certainly a fault with the film emulsion, and I would suggest sending them to Kodak for their opinion. Carry on developing, Vania!
Reply With Quote
  #4  
Old 11th March 2011, 08:53 AM
Vania Vania is offline
Friend
 
Join Date: Sep 2010
Posts: 10
Default

Thanks Peter for taking the time to answer. The same post is on the APUG forum http://www.apug.org/forums/forum37/8...ml#post1151099 where someone suggest that there might be an issue with undisolved crystals:

Quote:
Undissolved particles/crystals in the developer stuck to the emulsion. It looks like a comet around them because the developer becomes much more concentrated around the particles, and gravity forces it downwards when it slowly dissolves due to the agitation.
Even if I always check that part B is well disolved, I notice that there was some crystals on the neck of the part B bottle that could have felt undisolved in the developer... It's quite a stretch but do you think it's possible ?
If yes, someone suggested the use of coffee filters to keep the crystals out of the developer. Is this sound?
Again, thank you.
Reply With Quote
  #5  
Old 11th March 2011, 09:21 AM
Vania Vania is offline
Friend
 
Join Date: Sep 2010
Posts: 10
Default

Sorry Jim, i didn't see your post. Yes they all look similar.
Reply With Quote
  #6  
Old 11th March 2011, 09:24 AM
B&W Neil's Avatar
B&W Neil B&W Neil is offline
Friend
 
Join Date: Oct 2008
Location: West Cornwall
Posts: 4,053
Default

I looks more like mechanical damage to me and it could well be a manufacturing fault. Alternatively, some damage introduced during the developing process. Check spirals, rings, fingernails and anything else that comes into contact with the film from the time you unwind the spool.

Neil.
__________________
"The aim of art is to represent not the outward appearance of things, but their inward significance." Aristotle

Neil Souch - www.mono-inthedark.co.uk
Reply With Quote
  #7  
Old 11th March 2011, 06:21 PM
Peter Hogan's Avatar
Peter Hogan Peter Hogan is offline
Friend
 
Join Date: Sep 2008
Location: Buckinghamshire
Posts: 504
Default

The undissolved crystals idea doesn't sound credible to me. It does't make sense that dev would become more concentrated round a crystal, or anything else for that matter. Besides, the dev is at 24 degrees, and none of the components of either the A or B solution will remain solid in that temperature liquid, one of the reasons for using that temp, incidentally.
What is interesting is the identical shape and almost identical position of the marks on the neg; too coincidental for my mind.
Bear in mind also that in the many years I've been making and using this dev, some thousands of customers also, that the 'crystal' problem would surely have raised it's ugly head before now.....
I still stick with the faulty film prognosis....
Reply With Quote
  #8  
Old 11th March 2011, 06:59 PM
Richard Gould Richard Gould is offline
Friend
 
Join Date: Dec 2008
Location: Jersey Channel Islands
Posts: 5,229
Default

Vania, to me it looks like some form of mechanical damage to me,either a fault in the film, or damage caused to the film during the loading of the film into the spiral, maybe in the dark you caught the film with a nail,or something on your hand,maybe something on your spiral, Check your spiral, etc, Can not see it being chemical, not with developer,Richard
Reply With Quote
  #9  
Old 12th March 2011, 09:35 AM
JimW JimW is offline
Friend
 
Join Date: Aug 2009
Location: Worcestershire
Posts: 832
Default

Any chance of double exposure, even during (bad) manufacture? The comet looks too sharp, too clean and too consistent for a processing fault. Drying marks tend to be variable, badly mixed chemicals don't tend to give such sharp results. And for me it still looks like a highlight on the edge of a balloon. But I am guessing here.
Reply With Quote
  #10  
Old 12th March 2011, 02:21 PM
Vania Vania is offline
Friend
 
Join Date: Sep 2010
Posts: 10
Default

Thanks for all the contributions!
So, mechanical problem doesn't seem plausible simply because the neg has no sign of damage of any kind.
I have two last theories :

1. Could it be x-rays ? Although the films only went twice through them and only a few frames are concerned.
2. Could it be that the fixer somehow crystalized on the film ? And so when I checked the film for fog as usual only after one rinse after fixing, light could have hit those spots where the fixer has crystalized...

If not, I sure hope Peter's right! Quite a reassuring perspective given his experience...

Again thank you.
V.
Reply With Quote
Reply

Tags
development problem, prescysol, streak
Support our Sponsors, they keep FADU free:   AG Photographic   Keyphoto   The Imaging Warehouse   Process Supplies   RH Designs   RK Photo   Second-hand Darkroom Supplies   Silverprint Ltd

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
BBC Imagine "The Weird Adventures of Eadweard Muybridge" MartyNL Photography in general 15 4th December 2010 08:58 PM
BBC Imagine "Smash his camera" MartyNL Photography in general 2 24th November 2010 12:42 PM
Rollei retro 80S - use as "IR" film Michael Monochrome Film 28 5th January 2010 07:30 AM
Perceptol - Harman's "The Customers' Wish List" Mike O'Pray Darkroom 16 4th December 2009 07:14 AM
FS: DeVere 504 + Ilford 500 Multigrade head + 20"x30" 4 blade easel Fintan Sale or Wanted 2 25th October 2009 05:29 PM


All times are GMT. The time now is 12:45 PM.


Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2021, Jelsoft Enterprises Ltd.