What Zone is what?

[jag2x]

Hi all,

I'm using Dan Burkholders method of digital printing. What i've devised is a imagesetter negative of 101 squares. Each square contains a K Gray value from 0(pure white) to 100(pure black) within Photoshop.
I've contact printed this on Ilford Multigrade IV glossy paper. (Keeping all variables the same EVERY time I print)
I then used a denistometer to read each of these values from 0 to 100 of the paper.
The pure white starts at 0.04 and pure black is 2.04 density reading.

Now I know what the first Zone 0(pure black)(2.04) is and the last Zone 9(pure white)(0.04). What should I catergorize a density reading for the rest of the Zones?
Someone told me there is a forumla, to find the Zone 5(V), which is 18% gray.
You take log10(1/0.18)= 0.74 density reading. That is my mid gray.
Ok if 18% is mid gray what are the other values for the other zones? :|
Or have I answerd my own question here!? :)

So what I ultimatly want to do is know what curve to apply to the imagesetter negative to get a good tone on the Ilford paper.

Thanks
Jacek

[rwyoung]

I can't find the link, but somebody made a nice PDF document that has ZONE translated to negative and print densities. Same guy also has a nice paper calculator for use with spot meters and some other nifty stuff.

Briefly, from a copy I printed, reading from the Zone and Negative density columns:
0 => 0.00
I => 0.10
II => 0.24
III => 0.38
IV => 0.54
V => 0.72
VI => 0.90
VII => 1.10
VIII => 1.29
IX => 1.48
X => 1.67
XI => 1.85
XII => 2.02

I believe this should be interpreted as the density beyond FB+F
Also, note that he included 13 "zones".

I have seen other translations from Zone to net density and they generally match this table. Really, the key thing is to be consistant in the application of the technique as these are all relative measurements.

-- EDIT --
OK, looked at the fine print at the bottom of the chart and it says copyright Ralph W. Lambrecht so Google for him!

[Joe Lipka]

Using a reflection densitometer you measure the dot per cent area of the print and compare it to the per cent of the little squares. Or, you can hold the print next to your monitor and compare the tones in each of the squares using nothing but your eyeballs.

Transmission densitometers read negatives. Reflection densitometers read prints. Dan's method is based on reading the print, not the negative.

If you are trying to use a desktop printer to make your negatives you must use the same printer and inks that Dan uses. If you are using an imagesetter from an outside service, the curve should be straightforward.

[philsweeney]

there are few tools here that can help:

http://www.huntingtonwitherill.com/


http://home.att.net/~shipale/imgstr_curve_constr.xls

[jag2x]

Thanks guys for all the replies. Phil that website is great, explains alot of stuff in detail.
Cheers.
Jag