RE: Inkjet negatives and Van Dyke Brownprints

>>> dstevenbryant@mindspring.com 11/18/04 8:45 PM >>>
...
You may want to read Gary's article about digital negatives for VDBs at:

http://unblinkingeye.com/AAPG/DigiNegs/Overview.html
...
That's the trick, that is getting the proper gradation in the shadows
and
highlights...
>

Don Bryant

Don,

Thanks for the pointer to Gary's site. I had seen it and read the
article. But, it only adds to my bewilderment about the severity of
the correction curves. Look at Gary's curve values compared to mine:

input...Gary's output...My output
225...222...133
190...190...118
156...162...103
120...138...93
90...121...85
44...90...72
20...61...64
0...24...54

His range of values in the corrected negative is almost 200 levels while
mine is compressed to around 80 levels. We are both clipping the high
and low ends but my clipping is much more severe on both ends and the
curve much lower in contrast. I've tried my curve with a couple
different images and get similar (and nearly acceptable) results from
the negatives. I'm perplexed.

I'll make a set of comparison negatives using mine and Gary's data
tomorrow and test them together. I wonder if a paper difference or UV
source difference might account for the different ranges exhibited by
these two curves?

I'm using a one week old VDB solution compounded with distilled water.
It seems slightly faster than the aged bottle I just used up, but the
contrast and density range seems similar when printing. So, I don't
think I have a particularly contrasty emulsion.

In any event, thanks again for the info.

Joe
Received on Thu Nov 18 21:18:46 2004