TDLC-103 - Low contrast developer life expectancy

RogerHyam

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I've had a fun Sunday playing with an old (30+ year) stash of TechPan. I've made up some TDLC-103 (as per the Film Developing Cockbook V2).

I made it up as:

metol: 0.2g
Sodium sulfite: 2.5g
Sodium bicarbonate: 5g
Distilled water to 500ml.

Results are looking good as the negs dry. Certainly more like monochrome than black OR white which is the direction TechPan normally heads in!

My question is: How long can I expect my little bottle of dev to last, both in terms of films and time? Is there an easy way to spot exhaustion other than weak negs?

Your thoughts most appreciated.
 

koraks

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Your guess is as good as mine. I would say if the stars align, maybe a few weeks. A few months...? Probably not. Who knows?
Look, the good news is that it's a fairly low pH developer and in my experience, a soup like this lasts much better than a regular developer. But how long it will remain functioning to spec is virtually impossible to tell.
 

pentaxuser

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Roger, well on the plus side it looks easy and quick to make and uses remarkably little of any of the ingredients each time.

I might be wrong but unless 500ml can be used several times or at least twice then longevity fails to be important, doesn't it? With the amounts of the ingredients, isn't this at best a use-once developer for a 120 and given that a 35mm = 120 in terms of developer ingredients the same applies to 35mm

You might split it in two and try 2 x 135 films but just bear in mind the risk mentioned above

I'd appreciate a look at the negs if possible as may others of us here. Best way to show us the negs is a digital shot of them on a light box or against a window

pentaxuser
 
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RogerHyam

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Thanks for the thoughts.

Here is a phone snap of the negs. Just clip testing film with different times. They were done in the order 11min, 20min (some dry plates), 16mins. Rated at ISO 12.



I'll have a go at printing on multigrade tomorrow probably, the 20min and 16min ones, the 11min ones look too thin.

I make my own silver gelatine dry plates which I've always dev'd in Ilford PQ or maybe Ilfotec HC (HC-110) and found very contrasty and only suitable for printing out processes or scanning. But I souped a couple in this stuff today and the look like they might print on MG, maybe too soft! I'll know tomorrow. They take the night to dry.

My suspicion is this dev is a make-it-each-time-you-use-it one but that it will be good for a bunch of films.
 

koraks

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RogerHyam said:
the 20min and 16min ones, the 11min ones look too thin.
Click to expand...

Yeah. I'd say that the 16 min ones will print OK although I personally like to see a tad more shadow detail. YMMV. The 20 min ones look pretty bullet proof; they'll print, but generally the highlights don't stand up too well against this kind of density. Things tend to get fuzzy and ill-difined in those murky depths of silver deposits.

RogerHyam said:
My suspicion is this dev is a make-it-each-time-you-use-it one but that it will be good for a bunch of films.
Click to expand...

I'd certainly approach it that way in your place. It's still dirt cheap and relatively mild on the green stuff outdoors, though. I wouldn't sweat it.
 
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RogerHyam

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It's going to be weird tonality whatever. It's a document film used in microscopy lab then forgotten about in a bulk loader at the back of a storeroom some time in the 80s or 90s probably. Next step is to find a creative project to use it on. It'll suit those grey weather days.
 
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RogerHyam

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koraks said:
We've got plenty of those ahead of us in these parts.
I must say those negatives turned out surprisingly well, considering.

PS: I like your blog; I had a cursory look at it and I definitely need to read some more of it!
Click to expand...

Thanks. Your blog/colour work is amazing. I've always fancied carbon printing but don't have the space.
 

Don_ih

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The 16 minute ones look like they'll print easily at grade 2. If you want lower contrast with copy films, you need to photograph lower contrast scenes.

Maybe a "concentrate" of this developer can be mixed. 2g metol + 25g sulphite in 500ml water and a separate 50g bicarbonate in 500ml water to be added together and diluted when you use it. I think it would last quite a while. If the first solution turned dark, throw it away (the second would last forever?). I should try this with the Panchromatic High Contrast Copy Film I have.
At any rate, with that low an amount of developing agent, this developer shouldn't be reused.
 
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