- Start with a test strip at grade 2.5, right in the middle of the contrast range.
- The test strip is then exposed in a series of steps.
- Choose a step on the test strip that has some black areas as well as some detail in the light parts of your image. It’s usually best to go slighter darker if in doubt as to which step to choose.
- Take the time for the selected step and divide by 2, for example if the 30 second step looks about right this will give you 15 seconds.
- Do another test strip using this 15 seconds at grade 0 and 15 seconds at grade 5.
- In simple terms, the grade 0 low contrast exposure gives you control of the light grey areas in your print. To add more detail in these ‘highlights’ increase the grade 0 exposure time.
- To increase the overall print contrast increase the grade to 0.5, 1, 1.5 or 2. Be careful to avoid having white patches with no detail in your print. If this happens reduce the contrast again. Obviously if your print looks dull and without any bright areas (assuming it should have bright areas!) then decrease the exposure times until you see some.
- The high contrast exposure gives you control of the blacks and shadows. Increase this time until you see good blacks or decrease it until you can see some details in the shadows without completely losing your blacks. Be careful not to reduce your blacks to dark grey or your print will look low contrast! I always use grade 5 for the high contrast exposure.
For each exposure you can change the time and grade used giving you an almost infinite variety of possibilities. You can also dodge (selectively reduce the exposure of) parts of the image during each of these 2 basic exposures:
- To increase shadow detail and separation of the tones in these darker areas dodge these areas during the low contrast exposure.
- Another way to increase shadow detail is to reduce the grade 5 exposure.
- To give highlights subtle detail when they appear slightly over printed then dodge these during the low contrast exposure.
- If highlight (lightest) areas appear flat this is because the contrast is too low or the exposure is too long. Increase the grade or reduce the exposure used for the low contrast exposure.
- If it is difficult to put detail into the highlights using burning-in then reduce the grade used towards 0 for the basic low contrast exposure and maybe increase the time as well. Be careful not to reduce the overall impact of the print as you do this.
- If the print needs more contrast increase the grade 5 exposure time, reduce the low contrast time or increase the low contrast grade.
I also quite often make the foreground more contrasty by dodging the low contrast exposure for this area. I don’t want the viewer of my images to just look straight beyond the foreground to the main centre of interest. The whole picture sits on the foreground and increasing the contrast here gives it a prominent position in the final print.