[pure-silver] Re: re-using DDX

After reading those instructions what I did was:
- Have at least 4 or 5 tankloads for 1 session (35mm + 120)
   So I could develop 8-10 rolls in one night, kind of
marathonic actually but saved some money.
- Make 1l of 1+4 solution
- Use 600ml for 1 tankload
- Develop and return the 600ml to the 1 l
- Add 10% after the 2nd tank has been developed

Results are similar to one another.

BUT with LF films, wouldn't you need a lot less if using tubes??
in such case economy would become a secondary problem.


--- Richard Knoppow <dickburk@xxxxxxxxxxxxx> wrote:

> 
> ----- Original Message ----- 
> From: "Shannon Stoney" <sstoney@xxxxxxx>
> To: <pure-silver@xxxxxxxxxxxxx>
> Sent: Friday, March 31, 2006 10:28 AM
> Subject: [pure-silver] re-using DDX
> 
> 
> >I was reading the DDX bottle today and noticed the 
> >following:
> >
> > "For economy, DDX can be reused to process either a number 
> > of films individually or multiple films in batches.  If a 
> > series of films is being developed in a spiral tank, 
> > compensate for the loss of development activity after 
> > developing the first film (or batch of films) by 
> > increasing development time 10% for each successive batch. 
> > This relies on the used developer...being poured back into 
> > the working strength solution's storage bottle and mixed 
> > with the fresh, unused part of the developer before 
> > processing the next film/batch."
> >
> >
> > ??? I don't get it.  Pour the used developer back into 
> > some fresh working solution and then add 10% to your 
> > times?  But, how much fresh developer?  And how does that 
> > save any money if you need fresh developer to do it?
> >
> > --shannon
> >
>    It is a bit indefinite.
>    Most developers can be used for more than one roll or 
> batch of film by extending time. Usually, there will be a 
> loss of shadow detail because of the accumulation of 
> reaction products. To a large degree this can be compensated 
> for by replenishment. Older developers use a separate 
> replenisher solution, some later developers are replenished 
> by adding more developer. T-Max RS is an example of this 
> type. I beleive Xtol can be replenished the same way.
>    For simple replenishment the replenisher is added 
> according to the area of film developed, the amount of 
> developer being carried off by the film assumed to be enough 
> so that the volume of the developer remains constant. This 
> method works better than simply re-using developer, however, 
> for consistency sensitometric tests must be made 
> periodically. This last is how photofinishing machines and 
> motion picture developing machines are operated. There is 
> still a difference between fresh developer and replenished 
> developer. In automatic machines a "developer starter" is 
> used to condition fresh developer to minize the difference 
> when new developer is being used. The starter adds what 
> amounts to reaction products to the fresh developer. This 
> method is simply too bothersome for low volume home 
> darkrooms.
>    You are right to be confused by Ilford's instructions 
> since the effect on development time on re-use depends on 
> the volume of used developer to the volume of fresh 
> developer. For instance, a single 8 oz tankfull of used 
> developer when added to 5 liters is likely to have 
> insignificant effect.
>    Ilford used to be pretty good at answering e-mail, it 
> would be worth a few minutes writing to them for 
> clarification.
> 
> ---
> Richard Knoppow
> Los Angeles, CA, USA
> dickburk@xxxxxxxxxxxxx 
> 
>
=============================================================================================================
> To unsubscribe from this list, go to www.freelists.org and
> logon to your account (the same e-mail address and password
> you set-up when you subscribed,) and unsubscribe from there.
> 


__________________________________________________
Do You Yahoo!?
Tired of spam?  Yahoo! Mail has the best spam protection around 
http://mail.yahoo.com 
=============================================================================================================
To unsubscribe from this list, go to www.freelists.org and logon to your 
account (the same e-mail address and password you set-up when you subscribed,) 
and unsubscribe from there.

Other related posts: