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Showing posts with label strips. Show all posts
Showing posts with label strips. Show all posts

Wednesday, 4 January 2012

Test strips before printing.


The test strip is the foundation to obtaining a good final print. Unless you have one of RH designs excellent Analsyser Pro enlarging meters. If not the most common way of producing a test strip is with a sheet of card moved at timed intervals across light-sensitive paper. There are several things you need to set before doing the test: the size of the print, the aperture of the enlarging lens and making sure you have sharp focus.

10 x 8 test strip.
Once all this is done how big should the test print be? This is down to personal choice but you should consider whether the use of whole sheet, half, third or strips give the best test results. If using a test strip of about two inches (50 mm) you need to make sure that each segment includes a full range of tones from the lightest to darkest so you can see at which timed interval gives the best high values and shadow areas. It is much easier to achieve this with the larger test strip.

What should the time separation be? A good starting point for prints around the ten by eight size is five seconds. These intervals will give you a rough idea of what the exposure should be. This can be refined with further test strips of two and/or one second if needed.

On what grade of paper should you make the test print? Grade one is standard practice. If the method you use places your negatives at a particular grade In my case it is grade three then you should do your test print at that grade unless you are using the split grade method.

Related posts:

Evaluating your test strips