Does developing a blank roll use up developer ?

[grahamc]

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hello 

I 'developed' a roll of C41 film that didn't include any photographs (loading error!).  Of course the roll came out blank.  

In terms of the life (roll-count) of my developer, should I count this roll as 1 'use' , or is the newly mixed developer now still as good as new ?!

Thankyou very much  

[Pyrogallol]

This needs a chemist to say whether the chemicals have been used up or not?

[250swb]

I would pretend it didn't happen.

[skahde]

The developer contains reducing agents which are used up more by the air mixed in during development than by the contact with film. But depending on the formulation of the developer (enough sodiumsulfite that is) it can swallow quite an amount of oxygen from the mixed in air and you can use it to develop more than one film e.g. stock, undiluted (!) D75/ID11. Have a look into the data sheet for the developer and it will tell you how to handle this if it is possible. As far as I remember for D76 there is a 10% increase in time needed and you are fine. 

With C41 it should work too, with Tetenal 3 bath E6 it did afair, but refer to the manual and you will know. 

Edited May 6, 2023 by skahde

[LocalHero1953]

On first principles, not from any special knowledge.........developer acts on the exposed light-sensitive chemicals. If they have not been exposed, then the developer should not be used up by them (though would be by contact with air as explained above). It's fixer that will be used up more than usual by unexposed film: fixer removes undeveloped light-sensitive chemicals.

[Ouroboros]

I'd treat it as 1/16 of your allowance.  The film leader will have been processed as normal.

[grahamc]

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5 hours ago, Pyrogallol said:

This needs a chemist to say whether the chemicals have been used up or not?

Well they have been heated and cooled down again.  Sorry we aren't all as smart as you ! 

[skahde]

I'm not sure if the message came through in my last post: It doesn't matter if the film in the tank was exposed or not. You could even forget to put film in the tank and should treat the developer as beeing used after shaking it a few minutes. 

Edited May 6, 2023 by skahde

[skahde]

vor 7 Stunden schrieb Pyrogallol:

This needs a chemist to say whether the chemicals have been used up or not?

With a staining developer it's easy. Pour it out, look a the mess you got and you have your answer. Not saying they aren't nice developers, quite to the contrary! 👌

[250swb]

6 hours ago, skahde said:

With a staining developer it's easy. Pour it out, look a the mess you got and you have your answer. Not saying they aren't nice developers, quite to the contrary! 👌

It's C41 processing, as in a kit of chemicals that have both a processing life and a shelf life.

[skahde]

vor 41 Minuten schrieb 250swb:

It's C41 processing, as in a kit of chemicals that have both a processing life and a shelf life.

You noticed the nickname of the individual I quoted, did you? 

[250swb]

1 hour ago, skahde said:

You noticed the nickname of the individual I quoted, did you? 

I would never make an association between a nickname and the content of a post. I remember when ‘Mynobisbiggerthanyours’ got into an argument with ‘icanpisshigherthanyou’ and the outcome was very messy.