D23 | Pictorial Planet

Pictorial Planet

From the author of "The Art of Black and White Developing"


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D-23 has been around since the 1940's. Of the many people who used it Ansel Adams is one of the most famous. It's soft working, controllable, fine grained and forgiving of high contrast. And it's very easy to make. But here's a way to use it that's not often used and I tell you, it's really worth trying!

Want a versatile developer that'll cope with any film and provide rock solid dependability? Maybe you should be trying D-23 Replenished! D-23 was formulated to be a better D-76. According to Anchell and Troop's The Film Developing Cookbook is was designed to be especially reliable as a replenished developer, the type of reliability commercial labs needed. D-23 in and of itself was stable, had similar fine grain to D-76, and provided good shadow detail with controlled highlights. It excelled in contrasty situations where other developers might run away and burn out the highlights. Furthermore, it consisted of only two chemicals, Metol and Sodium Sulphite.


If mixing this up don't forget to take 2/3 of the water at 50c, then add a pinch of the sulphite to the water before fully dissolving the Metol. Finally, dissolve the rest of the sulphite and make up to 1Ltr. D-23's soft working nature and forgiving personality is complimented by a versatility that earns its place in any darkroom. It can be used as a stock developer for fine soft grain, with a similar look to D-76, or it can be diluted up to 1+3 for a different effect. These higher dilutions change how D-23 works on the film, moving from that fine grain developer (1+0) to a sharper developer (1+1) to an acutance and compensating developer (1+3). Many suggest that the best dilution of D-23 is 1+1 but not me. The secret sauce is to use D-23 with replenishment!

Replenished D-23

Replenishment is an old technique for using developers, not often remembered these days. When films were developed in deep tanks and/or commercial machines the developer was "topped up" with a special replenishment formula. Formulas were created to allow the developer to continue working consistently for thousands of films. These replenishment formulas were published and home darkroom photographers used them in their deep tank dunking systems. The idea was very simple. After a film processing session the deep tank was topped up to a filling mark with replenisher. This would go on for months if not years, topping up every week or so to keep the amount of developer constant in the tank.

And here's where the magic happens. As the developer becomes "seasoned" with film development by-products (and of course the replenisher) it subtly changes. It becomes a unique mix, a magic brew, that endows the negatives with a certain look, a look that makes special negatives, unique negatives, unique to that photographer and that darkroom. No one, anywhere else had that exact D-23 brew and could make those exact negatives.
Now, some would say that's just crazy. They might claim such things as "lack of consistent negatives" or "the developer is no longer to be trusted" but I would say try it and see. You might be pleasantly surprised.

Here's how to replenish:

Mix up and bottle separately a litre of D-23 and a litre of replenisher (DK-25R, formula below).

- Use the D-23 at full strength (you can't use replenishment if you dilute the developer) for two or three films, pouring the used developer back into the D-23 stock after each film. This begins the "seasoning" process and starts building up the bromide by-products in the stock solution. Get starter development times from
The Massive Dev Chart.

- Now, mark the top of the solution on the D-23 stock bottle, I use a sharpy. The mark will be near the top because it should be nearly full, remember you've been pouring the used developer back into the bottle. This sharpy mark will be used to top up the bottle after each subsequent film development.

- After the next film is developed first add 22ml of the replenisher (Dk-25R formula below) to the stock and then pour the "just used" developer back into the bottle, filling the bottle back up to the sharpy mark. You are now replenishing!

That's it! By adding 22ml of replenisher into the stock solution, and then topping the stock back up to the mark after each film you are using developer replenishment. You will be seasoning your D-23 and it will become better and better with age.

Note: For a while you'll be adjusting your development time a little until the stock settles down but it won't be much. And you will have to run your film through the camera at a slightly lower ISO than box as you'll lose a little film speed because of the bromide by product but it's not a big deal. However, do be prepared to experiment a bit with your favourite films until you nail the exposure and development time. And then watch your brew do its magic.

Do I use the developer (replenished) forever?

I don't. After 30 films I discard 3/4 of the stock developer and top up the bottle with fresh made stock. This means my "new" stock is already seasoned with the old. Some folk however, just keep on using it for years, replenishing as above. My fathers D-23 deep tank had stuff floating around in it that looked like alien life forms but it just kept on developing the most gorgeous negatives.


DK-25R, replenisher for D-23

*Kodalk Why not give it a try? You might find it's the best thing you've done for your photography in years.
Important: Remember, do testing before committing your prize photographs!

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