Split Grade Printing.
- This is used by many advanced printers to quickly discover the
perfect contrast and perfect exposure for a black and white print.
- The word grade comes from paper manufacturers that 'grade'
their paper by contrast. For example; grade one is a low contrast paper
and grade five is high contrast. Low contrast is sometimes called
soft while high contrast is called hard.
- Multicontrast paper can be made to produce any grade of
paper by altering the colour of the enlarger light during exposure.
Yellow light makes a soft print while deep magenta creates high
contrast.
- Numbered squares of coloured gel' called Multigrade Filters
can be placed inside a black and white enlarger to set the grade that
the printer wishes of his photographs. The number written on the
filter refers to the grade it will produce.
- If the darkroom printer has a colour enlarger he can use
the yellow and magenta dials to set the contrast. Turning a dial is
more convenient than swapping filters but colour enlargers are
limited to a highest contrast of four.
- Colour to Grade Settings are as follows. In each case Y:
refers to setting on the yellow dial and M: to the magenta.
Y:30 grade 0, M:20 grade 1, M:40 grade 2, M:100 grade 3, M:180 grade 4.
- A split grade print has been exposed twice; once at a low
grade and again at a high grade. For example; the exposure might be
four seconds at grade two and seven seconds at grade 4. This example
would produce a moderately high contrast print.
- Why split grade? It is very difficult to analyse how a
print will look just by viewing the negative. He might waste several
sheets of paper while selecting the correct exposure and then the
ideal contrast. If he could create a test print showing how the
photograph will look at various grades and exposures he could go
straight to the ideal print. And this is how ...
- A split grade test sheet is created by exposing the paper
in bands of increasing time across the paper at a low grade (eg. grade
1 or M:20) then again, this time longways, at a high grade (eg. grade 4
or M:180). This creates a photograph divided into squares, each square
representing a different exposure and a different contrast. See
example below ...
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