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Contrast filters and midtones

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Pieter12

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This is why doing a print with a 2.5 filter is exactly the same as doing the same print with a grade 00 and grade 5, both with the same time as the 2.5 grade filter
From RH Designs on split-grade printing: "Equal exposures through each filter produces a contrast equivalent to grade 2 (if Ilford Multigrade filters are in use). Thereafter, increasing the hard exposure by a stop will increase contrast by one grade, similarly decreasing it by half a stop will reduce contrast by half a grade."
 

DREW WILEY

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Different VC papers from different manufacturers differ in that respect. I wouldn't trust any generalization. Besides, who cares what alleged grade it is??? The whole point of VC papers is that you have a continuous continuum available, and are not restricted to set grades like in the old days. You don't even need to know what such "grades" means. You just have to understand the term "contrast" and know how to control it.

I am glad I was forced to learn under the stricter parameters of true graded papers. There were some lovely versions. But that just makes our present VC papers all the easier.
 

ParkerSmithPhoto

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I have found this to be untrue many times.
Perhaps a highly skilled split-grade printer can wrestle a good print out of an inferior negative. However, the OP is brand new to darkroom work.

My suggestion is to work on exposure and development to make great negatives that are easy to print on a single grade.
 

albada

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From RH Designs on split-grade printing: "Equal exposures through each filter produces a contrast equivalent to grade 2 (if Ilford Multigrade filters are in use). Thereafter, increasing the hard exposure by a stop will increase contrast by one grade, similarly decreasing it by half a stop will reduce contrast by half a grade."
My measurements using my home-built LED head show the above statement to be true. I can set LED power levels to be any ratio I wish, but which grades do they correspond to? Using Ilford V RC paper, I experimented with Stouffer wedges until my LED test strips perfectly matched those from Ilford filters with a tunsten lamp. The resulting table of power-differences matches the above statement within 0.1 stops for grades 0 to 4. Grades 00 and 5 are exceptions because I light only one LED for them (green for 00 and blue for 5).

For the technically minded, the formula is: grade = 4.1 - (B-G), where B and G are log2(attenuation) of blue and green, meaning they are the number of stops below maximum power of B and G. The formula tells us that for grade 2, blue is 2.1 stops dimmer than green (i.e., B-G=2.1), telling us that tungsten lamps output much less blue than green.

For the OP, I agree with ParkerSmiithPhoto above: Forget about split-grade (and LEDs); first learn the fundamentals of making good negatives and good prints.
I'll add one more: Try to avoid lighting subjects with both sun and shade. Sun+shade results in high contrast negatives that are difficult to print.
Mark Overton
 
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