Silberra S-23

Highly Smoothing Alkali-free Metol Film Developer

# S-23

Silberra S-23 is a single-solution contrast alkali-free metol films developer. Provides wide gamma of halftones and good detail of light areas, can be used as equalizing and contrast developer (depending on the solution) and helps to equalize image contrast.

Chemical Composition

Metol, sodium sulfite anhydrous, disodium edetate

Preparing Working Solution

Working solution is prepared by pouring the contents of the packs into water while continuously stirring the solution (use glass stick or special plastic stirring stick for chemicals). Distilled or filtered water is strongly recommended.
The method of preparation is as follows:
1) Warm 750 ml of distilled water up to 35-37 Celcium degrees (use mix of hot and cold water, or use microwave to warm up the water).
2) Pour contents of pack #1 into the water while stirring until the powder is completely dissolved.
3) Pour contents of pack #2 into the water while stirring until the powder is completely dissolved.
Do not begin mixing the contents of pack two until pack one is completely dissolved. If any lumps of powder form in your solution, they can be broken down with your stirring stick. As soon as the working solution is ready (powders are totally dissolved), add cold water to make up to 1 litre and stir.
Allow the solution to cool to room temperature, nominally 20-22 C. At this point the developer is ready to use. Filtering the solution is not obligatory but recommended option.

Development Times

Silberra S-23 Developer can vary greatly final sharpness and contrast of photographs by changing proportions of dilution of the working solution. Working solution with proportions 1:2 can be called the second working solution, and many photographers prefer this concentration of the Developer. Development times for different films with working solution 1:1 are indicated in Table 1, for working solution 1:2 - in Table 2.

Development Times Table #1 (1 :1 working solution)

Developer Film ISO Time, minutes Temperature
S-23 Adox CHM 125 100 6 20C
S-23 Adox CHM 400 400 8 20C
S-23 Arista EDU Ultra 100 100 11 20C
S-23 Arista EDU Ultra 100 200 15 20C
S-23 Arista II 100 100 11 20C
S-23 Arista Premium 400 400 8 20C
S-23 Fomapan 100 100 11 20C
S-23 Fomapan 200 200 7 20C
S-23 Fuji Neopan 100 Acros 100 9 20C
S-23 Ilford Delta 100 Pro 100 7 20C
S-23 Ilford Delta 400 Pro 400 7 20C
S-23 Ilford FP4+ 100 6 20C
S-23 Ilford HP5+ 400 8 20C
S-23 Ilford Pan F+ 50 7 20C
S-23 Ilford Pan 400 400 9 20C
S-23 Kodak Plus-X 125 7 20C
S-23 Kodak TMax P3200 3200 11 20C
S-23 Kodak TMax 100 100 10 20C
S-23 Kodak TMax 400 400 8 20C
S-23 Kodak Tri-X 400 400 8 20C
S-23 Rollei Retro 100 100 11 20C

Development Times Table #2 (1 :2 working solution).

Delta 100 Pro (ISO 100) – 21 minutes
FP4+ (ISO 100) – 22 minutes
Pan F+ (ISO 50) – 18 minutes
TMax 100 [100TMX] (ISO 100) – 22 minutes
APX – 100 (ISO 100) – 23 minutes
APX – 400 (ISO 400) – 24 minutes
Neopan 100 Acros (ISO 100) – 24 minutes
Fomapan100 (ISO 100) – 23 minutes

Usage Limits

1 litre of Silberra S-23 Developer working solution can be used to process up to 7 films of 135/36 type.

Side Effects

Silberra S-23 Developer is not suitable for push processing due to its chemical properties.


Keep Silberra S-23 Developer in cool, dry and dark place. Keep away from the children. It is optimal to store your working solution in opaque, chemically inert and tightly sealed containers with minimal air space in order to reduce oxidation.

Expiry Date / Shelf Life

Silberra S-23 sealed powder packs can be stored up to 12 months past the production date. S-23 Developer working solution can be stored for 6 months past the production date (in a tightly sealed bottle). Developer that was partly used can be stored in a closed bottle up to 45 days. Please note: the exhausted working solution can not be stored.

Disposal Regulations

Silberra developers and fixers must be disposed of in accordance with the rules and regulations of the country they are used in. Concentrated developers could be toxic and may harm the environment unless disposed in appropriate manner. Silberra recommends to use special disposal services provided by correspondingly licensed organizations which are eligible for photographic chemistry recycling/disposal.