Silberra ST-2

Silberra ST-2 is a contrast fine grain film developer with minimal grain and good light sensitivity, it provides wide gamma of halftones and has minimal fog level. Looking at final image details, this Developer can be attributed to transitive between standard negative developers (such properties like high contrast and no tinting) and equalizing developers (low graininess, high tonal range). Contains anti-fog agent.
Silberra ST-2 is supplied as a set of reagents in two separate packages, designed to create 1 litre of working solution.

Chemical Composition

Disodium edetate, metol, sodium sulfite anhydrous, sodium carbonate anhydrous, potassium bromide

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 30-35 Celcium degrees (use mix of hot and cold water, or use microwave for warming 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

Average development time for photo films in newly made Silberra ST-2 developer working solution will be 7-8 minutes at a temperature of 20°. Optimal time to process specific films is stated either by manufacturer of the film or can be learned from the development times table at this page (the table is being constantly updated).

Usage Limits

Silberra ST-2 Developer working solution is recommended for one-time use. However 1 litre of the Developer can be used to process up to 8 films of 135 type or up to 3 films of 120 type, subject to an increase in processing time of 10% for each film after the first.

Side Effects

Darkening or slight tinting of the working solution will not affect final quality of images while working with films. Please note that tinting or darkening mean that the developer is being exhausted and must be used with caution (increasing development times of 20% minimum) or not used at all.

Storage

Keep Silberra ST-2 Developer in a cool, dry and dark place. Keep away from 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 ST-2 sealed powder packs can be stored up to 12 months past the production date; ST-2 Developer working solution can be stored up to 4 months past the production date, and, if used, no longer than 20 days past the first use.

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.