Expansion

With modern films and developers, Expansions beyond N + 2 are difficult to achieve without a serious loss of image quality owing to increased grain and fog. In general, you should rely on higher than normal paper grades and/or negative intensification when extreme Expansion is required.

Intensification means processing the film through a special chemical bath with the intention of increasing the contrast of the negative after it has been developed and fixed. Ideally, intensification will add density to the highlight areas of the negative without greatly increasing grain. Photographer's Formulary offers a prepared formula called Chromium Intensifier that requires you to bleach, intensify, and then redevelop your negative. This is effective, but a more simple method is to intensify the negative in a bath of selenium toner. To intensify negatives in selenium:

1. Presoak the negative in a bath of water for five to ten minutes.

2. Re-fix in a bath of hypo without hardener for five minutes.

3. Tone in a bath of Kodak Rapid Selenium Toner diluted 1:3 with hypo clearing agent for five minutes. Agitate continuously.

4. Clear in hypo clear and wash.

Note: Selenium toner is highly toxic. This procedure should be done in a well-ventilated area. Read the instructions carefully.

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