D-23 Developer

D-23 has only 2 ingredients, but produces clean negatives with fine grain, excellent tonal separation, and good film speed.

D-23 is so easy to make, you can mix it fresh from powder every time! Use it once, and discard it.

Try D-23 diluted 1:1. It's even cheaper that way, and longer developing times give us better control when performing Development By Inspection - or when handling many sheets at once.

Not  Divided D-23

D-23 is a one-bath developer. It is not the same as Divided D-23, a 2-bath formula. Divided D-23 is also known as DD-23.

Are you looking for Divided D-23 ? See this article.

Not Perfect, Not New. Very Simple

D-23 is not perfect. Other developers may offer modest improvements in grain or acutance or film speed - but there are few developers that are as simple and easy to prepare. With large format film what matters most is tonality and ease of control.

D-23 is very similar to D-76, but D-23 lacks Hydroquinone, whose presence speeds up development. D-23 is therefore a slightly slower developer, with greater compensation and less risk of "runaway" high values.

D-23 hasn't been offered as a commercial product for decades - but keep in mind that manufacturers sell formulas that are profitable. They often modify formulas to give them longer shelf-life in the store, or make them cheaper and easier to manufacture on an industrial scale.

Sample Photograph by Ansel Adams

This famous 1944 Ansel Adams photograph was developed in D-23. You can purchase a copy from the Ansel Adams Store. Mr. Adams describes it in Examples: The Making of 40 Photographs, pp. 164: "I used my 8x10 Ansco view camera with the 23-inch component of my Cooke Series XV lens with a Wratten No. 15 (G) filter. The film was Isopan, developed in Kodak D-23."

Winter Sunrise from Lone Pine
Ansel Adams, 1944
Technical Discussion

Here are a few interesting quotes concerning D-23 from The Darkroom Cookbook, by Stephen Anchell:

"Developers are made up of four basic components:

  • Developing agent
  • Preservative, which slows the rate of developer oxidation
  • Accelerator (or alkali) which energizes the developer
  • Restrainer, which restricts the formation of excessive fog and/or slows the rate of development.

All four of these components are necessary for the development process to be successful. Often, however, one chemical will serve more than one function. For example, Sodium Sulfite is usually used as a preservative to prevent oxidation. In the film developing formula Kodak D-23 the large amount of Sodium Sulfite (100 grams) serves to create an environment sufficiently alkaline that the developing agent, Metol, can reduce the Silver Halide without an additional accelerator. As development proceeds, soluble Bromide is precipitated out of the film, acting as an effective restrainer. D-23 has only two chemicals - Metol and Sodium Sulfite - yet as a developer it has all four of the required components" - pp. 40

Anchell mentions that many general-purpose developers contain 2 developing agents, like D-76 which uses Metol and Hyrdoquinone: the two agents work faster together. This is known as Superadditivity. However....

"... it would seem that the best developers to use are those that exhibit superadditive characteristics. Most general-purpose developers fall into this category. However, there is a flip side. Most developers that utilize this effect tend to yield greater high-value density than those that rely on one developing agent. A developer of the semi-compensating type using either metol or pyro alone in a solution of relatively low pH, is capable of producing brilliant high values, full-scale mid-tones and shadows (e.g. Kodak D-23 and Kodak D-1, ABC Pyro, especially Edward Weston's variation)." - pp. 42

"Kodak D-23 This is a semi-compensating developer that produces fine shadow values while retaining a high emulsion speed... Note: This developer produces negatives of speed and graininess comparable to Kodak D-76, without D-76's tendency to block highlights. " - pp. 150

Mix It Yourself: Always Fresh

When you mix your chemistry fresh every time, there's no danger of stock solution going bad on the shelf. If you've ever had the experience of using expired stock solution, you'll appreciate this point.


Ingredient Full Strength 1:1 Dilution
Metol 7.5 g 3.75 g
Sodium Sulfite 100 g 50 g
Water to make 1 Liter 1 Liter
Make 1 liter as follows: Dissolve the Metol first - then the Sodium Sulfite - into 1/2 liter of water at 125 degrees Fahrenheit (52 degrees Celsius). Add 1/2 liter of cold water (or ice water) to reduce temperature to 68 degrees Fahrenheit or (20 degrees Celsius).

Developing times for D-23 are similar to those of D-76. I develop Kodak TMAX 400 and Ilford HP5+ for around 9 minutes in D-23 1:1 at 70 degrees Fahrenheit (21 degrees Celsius).

In the USA, a good source for materials is Artcraft Chemicals.

More Sample Photographs

Here are some recent photos developed with D-23.

Typewriter, 2014
Kodak 2D, 10 3/4" Goertz Red Dot Artar
5x7 HP5+, D-23

Massachusetts, 2013
Kodak 2D, 10 3/4" Goertz Red Dot Artar
5x7 HP5+, D-23

Plant and Shoes
Sinar P, 200mm Nikkor M
4x5 TMY, D-23

Pottery, 2014
Sinar P, 190mm Bausch & Lomb Tessar
4x5 TMY, D-23

Architectural Detail
Sinar P, 450mm Fujinon C
4x5 TMY, D-23

Antique Model Airplane
Sinar P, 210mm Macro Sironar
4x5 TMY, D-23

Massachusetts, 2015
Sinar P, 450mm Fujinon C
4x5 TMY, D-23