add section on highly dilute D-23
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@tundra tundra authored on 5 Aug 2023
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README.md
not lift the reel off the bottom of the tank enough to consistently
avoid bromide artifacts on the bottom edge of the film.
 
 
### Update 8-5-2023: Super Dilute D-23
 
D-23 is easy to make and is often used when you need to control a
very long Subject Brightness Range. That's because it's a so-called
"compensating" developer that nicely reins in the highlights.
 
**NOTE**: Ignore rumors you may have heard that D-23 is a "low
contrast" developer. It will deliver the contrast you want
based on how you work with it.
 
I've gotten very good results with D-23 stock as well as 1:1 when doing
semistand and EMA development. But I wanted to push the dilution
envelope a bit. Why? D-23 is a "solvent" developer made of only
Metol and Sodium Sulfite. The Metol is the development agent
and the Sodium Sulfite acts as a preservative and produces the
required alkalinity for the developer to work properly.
 
In normal dilutions, the Metol in it "chews away" at the grain. That's
the "solvent" effect. This helps keep the grain under control, but it
does so at the expense of absolute sharpness.
 
By diluting beyond the recommended amount, we reduce the amount of
Metol in the working developer so there is less of that solvent effect
and the negative is rendered more sharply.
 
Up to dilutions of about 1:4, I got consistently good results from
semistand with D-23. Beyond that, though, the reduction in the
amount of Sodium Sulfite in solution reduces its alkalinity to the
point that the developer stops working well.
 
Someone on the UK Large Format forum suggested that I try D-23 at a
1:9 dilution but add 0.5 grams/liter of lye (Sodium Hydroxide) to the
mix to kick up the alkalinity. This works just great - you get super
sharp negatives with this scheme. HOWEVER, you won't want to do this
with smaller format/grainer films. For example, 35mm Kodak Double-X
done this way produced really grainy negatives reminiscent of highly
dilut Rodinol
 
**WARNINIG**: Be careful handling lye. It will burn skin, cause
damage to eyes, and so on. As always, use sensible
lab techniques and wear protection in the darkroom.
Lye added to liquid is exothermic and can generate
a lot of heat, so be careful and take your time.
 
For the record, I also tried this with DK-50 at 1:5 and got less
wonderful results. It certainly worked, but I didn't like how the
tonal range got handled. The negatives came out sharp but sort
of harsh looking. I think it may be that DK-50 has Hydroquinone
in it, but I'm not sure. I didn't test it as thoroughly as I did
D-23 so it might just be a lack of understanding on my part.
 
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