A Photography forum. PhotoBanter.com

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Go Back   Home » PhotoBanter.com forum » General Photography » In The Darkroom
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

the effects of aging on developers



 
 
Thread Tools Display Modes
  #1  
Old January 24th 04, 06:14 PM
Robert J. Mathes
external usenet poster
 
Posts: n/a
Default the effects of aging on developers

This question may be a bit of a handful. My question concerns developers and
what are the effects on the print or film as the developing agents age. I
know most, or I should say those that I use (powdered mix D-76 and Dektol
and Selectol), say a shelf life of 2 months in a tightly-stoppered dark
bottle is the limit and I follow that suggestion. But what I would like to
know is what can be expected as the developing agents age. Are the effects
uniform or do the highlights suffer first and shadow detail second or vice
versa? I guess what I'm asking is if the component developing agents
deteriorate at different rates. What happens if you go beyond the suggested
shelf life. Is there some kind of compensation that can be made for the
aging of the developing agents?
I'm hoping to get replies based on obviously more knowledge, but also
the breath of experience that others have in processing their own film and
prints. All replies will be welcomed. Thanks!




  #2  
Old January 25th 04, 02:23 AM
Richard Knoppow
external usenet poster
 
Posts: n/a
Default the effects of aging on developers


"Robert J. Mathes" wrote in message
...
This question may be a bit of a handful. My question

concerns developers and
what are the effects on the print or film as the

developing agents age. I
know most, or I should say those that I use (powdered mix

D-76 and Dektol
and Selectol), say a shelf life of 2 months in a

tightly-stoppered dark
bottle is the limit and I follow that suggestion. But what

I would like to
know is what can be expected as the developing agents age.

Are the effects
uniform or do the highlights suffer first and shadow

detail second or vice
versa? I guess what I'm asking is if the component

developing agents
deteriorate at different rates. What happens if you go

beyond the suggested
shelf life. Is there some kind of compensation that can be

made for the
aging of the developing agents?
I'm hoping to get replies based on obviously more

knowledge, but also
the breath of experience that others have in processing

their own film and
prints. All replies will be welcomed. Thanks!

Stock, unused, D-76, Dektol, Selectol, etc., should have a
minimum life of about 6 months in a filled, sealed bottle.
In a partly filled bottle its less. Kodak gives 2 months,
but that is conservitive. If kept away from heat it should
last longer.
The main thing that happens to developer is oxidation. The
oxidation converts part of the sulfite to sulfate and can
oxidize the some of the developing agents. In the case of
Metol the oxidized forms are not active developing agents.
Hydroquinone oxidation products can be even more active than
the base form.
Packaged D-76 is buffered so there is little change in
activity with time. The original D-76 formula rises in
activity with time due to a slow reaction between the
hydroquinone and sulfite. This produces some sodium
hydroxide which raises the pH of the solution. Since the pH
is fairly low to begin with it has significant effect over a
period of perhaps a month. The buffered variety can handle
the hydroxide so its pH stays constant.
The same effect takes place in all hydroquinone developers
but Dektol, for instance, so much higher in pH than D-76
that the effect is masked and is of no significance.
M-Q developers, like Dektol and D-76, and most Phenidone
developers, are quite stable with time. Some developers, in
particular Amidol and some Pyro formulas, are not at all
stable and have a very short lifetime once exposed to air.
Pyro can be protected by additions of Sulfite and Metol,
but, if enough sulfite is added to give it long tray or tank
life, it looses its staining and tanning properties since
these are due to oxidation products and the sulfite prevents
them from forming.
I have had packaged D-76 stay good for a year after mixing
(I don't recommend this) and Dektol for rather longer than
the advertised time. Dektol starts out straw yellow and
becomes progressively browner as it ages. If its quite brown
toss it. Eventually, if they become oxidized enough,
hydroquinone developers will develop a very offensive odor.


--
---
Richard Knoppow
Los Angeles, CA, USA




  #3  
Old January 25th 04, 05:20 AM
Ken Hart
external usenet poster
 
Posts: n/a
Default the effects of aging on developers


"Robert J. Mathes" wrote in message
...
This question may be a bit of a handful. My question concerns developers

and
what are the effects on the print or film as the developing agents age. I
know most, or I should say those that I use (powdered mix D-76 and Dektol
and Selectol), say a shelf life of 2 months in a tightly-stoppered dark
bottle is the limit and I follow that suggestion. But what I would like to
know is what can be expected as the developing agents age. Are the effects
uniform or do the highlights suffer first and shadow detail second or vice
versa? I guess what I'm asking is if the component developing agents
deteriorate at different rates. What happens if you go beyond the

suggested
shelf life. Is there some kind of compensation that can be made for the
aging of the developing agents?
I'm hoping to get replies based on obviously more knowledge, but also
the breath of experience that others have in processing their own film and
prints. All replies will be welcomed. Thanks!


Others here can answer your question much better, but the _very_general_
answer is the developer activity decreases with age. Black areas will not
develope fully. You will get less contrast. If you _absolutely,_positively_
had to use some old developer, I'd increase the developer time, perhaps by
25-50%.

As for the 2-month shelf-life, I prefer the guideline: "If it's brown, flush
it down".

Ken Hart


  #4  
Old January 25th 04, 11:02 PM
Nicholas O. Lindan
external usenet poster
 
Posts: n/a
Default the effects of aging on developers

"Ken Hart" wrote

If you _absolutely,_positively_ had to use some old developer


Reference for information: "Lootens on Photographic Enlarging
and Print Quality." Available from Abebooks and Amazon for
$1.25 and up, a bargain.

In the old days, old developer was used 1:1 with fresh developer
to shift warm tone paper farther towards the warm end.

I can't say I have tried it, as my warm-tone paper stock went
with the use of the last of my Agfa Portriga (?).

WBUAT: Is there a modern equivalent of the old warm tone papers
among all these Bergers and Kentmeres and Rajahs ...

There was also advice to add Sodium Carbonate to old developer
to revitalize it. Somewhere around 1/2 oz Na2CO3 to 32 oz
shot developer.

--
Nicholas O. Lindan, Cleveland, Ohio
Consulting Engineer: Electronics; Informatics; Photonics.
  #5  
Old January 26th 04, 12:52 AM
Patrick Gainer
external usenet poster
 
Posts: n/a
Default the effects of aging on developers



"Nicholas O. Lindan" wrote:

"Ken Hart" wrote

If you _absolutely,_positively_ had to use some old developer


Reference for information: "Lootens on Photographic Enlarging
and Print Quality." Available from Abebooks and Amazon for
$1.25 and up, a bargain.

In the old days, old developer was used 1:1 with fresh developer
to shift warm tone paper farther towards the warm end.

I can't say I have tried it, as my warm-tone paper stock went
with the use of the last of my Agfa Portriga (?).

WBUAT: Is there a modern equivalent of the old warm tone papers
among all these Bergers and Kentmeres and Rajahs ...

There was also advice to add Sodium Carbonate to old developer
to revitalize it. Somewhere around 1/2 oz Na2CO3 to 32 oz
shot developer.

--
Nicholas O. Lindan, Cleveland, Ohio
Consulting Engineer: Electronics; Informatics; Photonics.

All I can say is I'm 76 years old and still developing. Sorry, I
couldn't resist.
  #6  
Old January 26th 04, 01:01 AM
Jorge Omar
external usenet poster
 
Posts: n/a
Default the effects of aging on developers

Patrick Gainer wrote in news:401464B3.E13201D7
@rtol.net:

There was also advice to add Sodium Carbonate to old developer
to revitalize it. Somewhere around 1/2 oz Na2CO3 to 32 oz
shot developer.

--
Nicholas O. Lindan, Cleveland, Ohio
Consulting Engineer: Electronics; Informatics; Photonics.

All I can say is I'm 76 years old and still developing. Sorry, I
couldn't resist.


With sodium carbonate???

((-:

Jorge
  #7  
Old January 26th 04, 07:00 AM
Patrick Gainer
external usenet poster
 
Posts: n/a
Default the effects of aging on developers



Jorge Omar wrote:

Patrick Gainer wrote in news:401464B3.E13201D7
@rtol.net:

There was also advice to add Sodium Carbonate to old developer
to revitalize it. Somewhere around 1/2 oz Na2CO3 to 32 oz
shot developer.

--
Nicholas O. Lindan, Cleveland, Ohio
Consulting Engineer: Electronics; Informatics; Photonics.

All I can say is I'm 76 years old and still developing. Sorry, I
couldn't resist.


With sodium carbonate???

((-:

Jorge

Sometimes a little wine helps.

Pat
  #8  
Old January 27th 04, 12:01 AM
Robert J. Mathes
external usenet poster
 
Posts: n/a
Default the effects of aging on developers

Thank you all for your replies. They have all helped..........except for the
76 year-old's, that is!

bob mathes


 




Thread Tools
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

vB code is On
Smilies are On
[IMG] code is Off
HTML code is Off
Forum Jump


All times are GMT +1. The time now is 09:01 PM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
Copyright 2004-2018 PhotoBanter.com.
The comments are property of their posters.