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 printing techniques

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

Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 1st October 2020, 05:57 PM
Nat Polton Nat Polton is offline
Friend
 
Join Date: Oct 2019
Posts: 292
Default Benzotriazole anti-fog

Benzotriazole can be used in the print developer as an anti-fog additive.
Used when you have old out of date bromide paper to use up.
The internet has a few pieces of information regarding the percentage of the stock solution to be made up, and the amount to mix into the developer.
Trouble is, no one seems to agree with each other as to the quantities to use etc..
Has anyone had any personal experience of using this chemical, and what stock solution to mix, and how much to use in the developer ?
Cheers.
__________________
It will all be over by Christmas.
Reply With Quote
  #2  
Old 1st October 2020, 06:12 PM
Lostlabours Lostlabours is offline
Friend
 
Join Date: Apr 2012
Location: West Midlands/Aegean
Posts: 1,651
Default

My experience with 1950's and 60's Ilford and Kodak Bromide papers is loss of speed and maybe a grade contrast but no fog.

I had many hundreds of sheets of 50's and 60's Bromide paper, and tested it all before giving it to people who ran workshops.

Fogging from poor storage is another issue. doesn't need to be old at all in this case.

I have a lot of Benzotriazole. powder and in Solution, in over 50 years of darkroom printing I've never used it unless a developer formula includes it.

Ian
Reply With Quote
  #3  
Old 2nd October 2020, 12:57 PM
Terry S Terry S is offline
Friend
 
Join Date: Dec 2011
Location: Southend on Sea, Essex, England UK
Posts: 2,376
Default

Quote:
Originally Posted by Nat Polton View Post
Benzotriazole can be used in the print developer as an anti-fog additive.

Trouble is, no one seems to agree with each other as to the quantities to use etc.
I too have some in stock, but to date have never had to use it as you suggest.

I bought a small quantity as I am now making my own brews from individual chemicals, and as stated, some formulas include it.

From what I've read, one uses a 0.1% solution, (which would be 1 gramme in one litre of VERY hot water at 125F / 52C or higher, as it won't dissolve in lower temperatures) and then using up to 5ml in your diluted developer, starting at 1ml, until you (hopefully) solve the fogging problem. I say this as I don't think that it is a cure all, in all cases.

Hopefully Pentax Pete will see this question, as he has done a lot of videos about this type of thing.

Terry S
Reply With Quote
  #4  
Old 2nd October 2020, 02:05 PM
Mike O'Pray Mike O'Pray is offline
Friend
 
Join Date: Oct 2008
Location: Daventry, Northants
Posts: 7,778
Default

I recall from Photrio, I think, that stronger solutions of benzo will work up to a certain level of age fogging but not beyond that. I'd imagine that anything up to light grey might be curable but once you get beyond that then while you will clear the borders back to a light grey or possibly very light grey then you may have to live with slightly grey borders which as long as the picture comes out OK may be fine.

Depending on the photo a light grey border might look OK

Mike
Reply With Quote
  #5  
Old 3rd October 2020, 07:38 AM
GoodOldNorm's Avatar
GoodOldNorm GoodOldNorm is offline
Friend
 
Join Date: Oct 2009
Location: Derbyshire UK
Posts: 1,110
Default

I have used up to 15ml of a 1% solution of benzo. Added to my print developer. Adding more benzo than that amount will do nothing for paper that is heavily fogged by ageing. Compare a print made on new paper next to successive prints made on your fogged paper adding 5ml, 10ml and then 15ml of benzo. 1% solution. Or jump right in with 15 ml benzo. Per. Litre of print dev. Compare the whites to the whites on your fresh paper print any degree of grey on the old paper will be easy to see.
__________________
"The whole problem with the world is that fools and fanatics are always so certain of themselves, and wiser people are so full of doubts. "
Bertrand Russell
Reply With Quote
  #6  
Old 3rd October 2020, 07:42 AM
GoodOldNorm's Avatar
GoodOldNorm GoodOldNorm is offline
Friend
 
Join Date: Oct 2009
Location: Derbyshire UK
Posts: 1,110
Default

I have used up to 15ml of a 1% solution of benzo. Per 1ltr of print dev. added to my print developer. Adding more benzo than that amount will do nothing for paper that is heavily fogged by ageing. Compare a print made on new paper next to successive prints made on your fogged paper, adding 5ml, 10ml and then 15ml of benzo. 1% solution. Or jump right in with 15 ml benzo. Per. Litre of print dev. Compare the whites to the whites on your new paper print, any degree of grey on the old paper will be easy to see.
__________________
"The whole problem with the world is that fools and fanatics are always so certain of themselves, and wiser people are so full of doubts. "
Bertrand Russell
Reply With Quote
  #7  
Old 4th October 2020, 12:47 PM
Terry S Terry S is offline
Friend
 
Join Date: Dec 2011
Location: Southend on Sea, Essex, England UK
Posts: 2,376
Default A few variations of using benzotriazole

Well, having read over the years many times to use a @ 0.1% solution, I took to my books for a definitive answer.

So prepare to be educated / even more confused than ever...

First, the Darkroom Cookbook, which says:

'Mix a 0.2% solution (2 grammes in 1 litre water at 125F / 52C or higher). Add 15.0ml of this solution to every litre of (working strength) developer. If 15.0ml does not do the trick, keep adding 15.0ml at a time... until you get a clear paper without a fog. A little experimentation will be required.'

Note that it doesn't give a maximum amount that can be added, but general reading says that adding too much will introduce even more fog.

Secondly Ansel Adams, The Print states that he uses a '1.0% solution, adding 25cc to stock developer solution.' It says that 50cc produces a noticeable blue colour shift of the paper and 100cc reduces paper speed by about 2/3 of a f-stop.

Thirdly and last is from Tim Rudman's Master Printing Course book:

'Benzotriazole 1%. 5ml in 1 litre of working developer. Expose to the shortest recommended development time and then experiment to ensure maximum blacks.'

Also recommended in his book and else where, is the use of potassium bromide 10%; using 10ml in 1 litre of working solution.

Note that bromide gives a warmer image compared to a cooler one with benzotriazole.

Hopefully this will all be of help and the bottom line seems to be to experiment a bit.

Terry S
Reply With Quote
  #8  
Old 4th October 2020, 04:02 PM
Mike O'Pray Mike O'Pray is offline
Friend
 
Join Date: Oct 2008
Location: Daventry, Northants
Posts: 7,778
Default

Thanks for the summary of instructions, Terry. Just a pity perhaps that that the wording in the Darkroom Cookbook gives me the impression that clear paper will always result, eventually, which is unlikely to be the case with paper fogged beyond a certain level.

Mike
Reply With Quote
Reply
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
Farmers Reducer or Benzotriazole? MarkH Monochrome printing techniques 7 6th April 2018 06:51 PM
Benzotriazole Strength. Bill Monochrome printing techniques 15 20th April 2011 08:47 AM
Anti-halation backing cliveh Monochrome Film 0 15th April 2011 08:15 PM
New Anti-Spam / Anti-Hacker software Installed. Bob Feedback and forum matters 6 6th October 2010 09:55 PM
Anti-fog StanW Ask Les 1 12th September 2009 10:26 AM


All times are GMT. The time now is 08:50 PM.


Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.