WT / CT developers can not be kept?
Up to now, I have been using Ilford Multigrade developer to develop my prints. However, last week I saw some Harman / Ilford Warmtone developer in a shop and wanted to give it a try. However, reading the instruction sheet that came with the developer, it states that working strength (1:9 diluted that is) can only be kept for "up to 24 hours" even when in a "tightly capped bottle".
Is this true, and what is the reason why working strength WT / CT developers can not be kept?
It seems like a big waist of developer... and can one apply replenishing? (remove 100cc / per liter and add fresh 100cc developer concentrate), instead of having to ditch 2 liters of developer each day???
Most print developers have a very short working strength life. They are very active developers in general, and they get a lot of oxygen mixed in when used in trays for print processing. The act of agitating a print oxidizes the developer. If you are continuously processing over several days and you have a big volume of developer in your tray (say 1/2 gallon, or so) then you can "get by" with spiking the developer with some fresh, but the developer will start turning brown, making it hard to evaluate the print. This is general information for all print developers. The fact that print developers need to be very active developers means that they cannot have the amount of restrainers and preservatives in them that film developers can. These restrainers and preservatives tend to "slow down" oxidation.
OK, but *one* day in "tightly capped bottle"?
Originally Posted by PHOTOTONE
I understand the developer oxidizes and gets brown. But I never judge my prints when in the developer, instead wait until they are fully processed and than switch on some daylight type lighting in my darkroom to have a closer look...
So, besides the developer becoming a little less active, and turning brown, is there really a need to ditch a WT / CT developer within a day? Are there any serious negative consequences to be expected of using oxidized - but still active(!) - developer, e.g. in terms of archivability?
I have sometimes kept my Ilford Multigrade developer for weeks... (in a closed bottle of course). Maybe I am sloppy in this, but it is still usable after these times...
I agree with PHOTOTONE.
I like Ilford ID-78 as a Warm Tone Print Developer. To warm the tone further, I add Potassium Bromide to the working solution. To Cool the tone (to a Blue-Black) I add Benzotriazole to the working solution.
In December 2005 I mixed concentrated ID-78 stock solutions (A and B). These stock concentrates are still going strong today.
I use the working developer as a one-shot (it is inexpensive).
Propylene Glycol @140deg. F, 100ml
Hydroquinone 12.00 g
Phenidone 0.50 g
Sodium Sulphite, anhyd 50.00 g
Sodium Carbonate, anhyd 62.00 g
Potassium Bromide 4.5 g
Water to make 1 litre
Everything is analog - even digital :D
I reuse the cooltone developer for ages. It seems to keep fine to me so I'm puzzled over the 24hours warning too. Then again, as I keep saying, I'm probably just not picky enough.
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Ok, if others have contributions in terms of the working strength life time, I would gladly hear them...
Tom's detailed answer with recipes raises another question though:
- How do these WT/CT developers actually work???
I mean: silver is silver? :o
How can a developer actually change the "tone" of the print??? What is the chemistry or physics behind their workings? Is it a change in the size or shape of the silver particles? Or are there actually more substances deposited than just plain metallic silver in a silver print??
Most one shot developers don't keep well for more then a day or so but as you suggest I replenish my Ilford/Harmon WT & CT working strength developers. For each new print session I mix up fresh developer and add about a third of oxidised old developer to make up to the total volume. As yet I've had no adverse effects, blacks are as deep as when using just fresh developer.
You may want to experiment and perhaps try a 50:50 mix.
The image tone of a print paper is mostly determined by the emulsion design and thus by the paper manufacturer. Print Exposure and development can modify the image tone and color to a degree by increasing and decreasing image fog (through the use of restrainers - potassium bromide and/or benzotriazole) and by changing image contrast (via developer dilution and activity changes).
Originally Posted by Marco B
Everything is analog - even digital :D
Have a look at this link: http://www.retrophotographic.com/moerschchem.htm
The Moersch SE2 Warm developer keeps for a number of weeks in its diluted working strength form.
So not all WS diluted developers are 'one-shot', use only once then throw away. Clearly there are some out there that keep well (if in full containers) and can be reused.