what digi greyscale equivilents for zone system?

[Darin Cozine]

I've been having problems visualizing how scenes will look in black and white.
I would like to experiment using digital images to get a better feel for the zone system and visualization for color to black and white conversion.

So, in a standard 8-bit greyscale (values from 0-255) where would the varous zones be?

Thanks.

Darin

www.cozinephoto.com

[jonathan smith]

That's an interesting idea, it would be great to have those numbers, if it works.
I just checked the website link http://www.cicada.com/pub/photo/zs/tables/31.html (http://www.cicada.com/pub/photo/zs/tables/31.html) which says there are 10 zones, with 11 values. Thus, each step goes up 25.6. So, the rounded values would be:

zone 0, black, is 0 zone 1 is 26 zone 2 is 51zone 3 is 77 zone 4 is 102 zone 5 is 128 (middle gray, the center point) zone 6 is 154zone 7 is 179 zone 8 is 205 zone 9 is 230 zone 10, white, is 256 (or 255, whatever)

It would be interesting to run these out on a printer and see if they look right visually or if they have to be tweaked.

[Leonard Evens]

I've done that same computation, and I find the values are not really accurate in terms of my visual response. But a lot depends on how your monitor is calibrated. Mine is calibrated for a gamma of roughly 2.2.

Here is what I am currently using, but remember these are just tentative ballpark numbers . I regularly change these numbers, sometimes significantly, in light of experience. Also, the zones are really ranges, so use a figure of +/- 10 or so about these numbers.

X 255

IX 245

VIII 225

VII 195

VI 165

V 130

IV 100

III 75

II 50

I 25

O 0