Re: How to apply curves in PS for digital negatives...

I agree, Michael.

First, I want to brag about a student.

Remember when I asked you guys a bunch of questions about salt, fixing, and
such? Well, with your help, and the help of a correctly calibrated PDN
curve for salt, BJ got juried into the undergraduate art show here at MSU, a
very competitive show as it is for all arts. His large salt print of the
inside of a laundry was beauuuuutiful--light streaming through a window,
glowing white shirts hanging in a row. He won one of the five prizes
awarded out of 50 works--photography in an art show, no less (sarcastic
comment). What it made me realize is how beautiful a correctly done salt
print is. The tonal range is gorgeous, especially in the highlights.

With the correct curve.

I work on an Epson 2200, he on an Epson 4000. His curve is different than
mine and he has to lay down more ink with the 4000 than I do, in the ink
config dialogue box of the printer. This is the beauty of the PDN system,
that you can find out your own curves.

Next semester I will attempt my first trial at teaching a **classful** of
students PDN. Pray for me :)

BJ "got it" in about 4 hours because he is digitally savvy; the digi prof
here "got it" in 1 1/2--you can just see the light bulb turn on when they
realize the beauty of the system. I took 3 weeks because I had to make
every mistake under the sun learning it--but that'll make me a better
teacher next semester for sure.
Chris
PS There certainly may be other equally good methods out there of building
curves--I've seen prints from Clay, Dan B, etc. that are proof of that! We
are in a wonderful digineg moment in history with all these great guys doing
all the computer work so we can ride on their coattails.

Michael K-S said:
I look at many of the curves in the curves area of
alternativephotography.com and just roll my eyes. Half of them look totally
wrong to begin with and other half give you no details on how there were
produced, what printer, what paper, inks, times et al. No one has mentioned
so far, although it's been said many times, that applying a generic curve
like this will probably only produce mediocre results -- if you're lucky. To
truly reap the benefits of the curve function you have to print YOUR OWN
step tablets so you can match the tones from your output (i.e. the final
VDB) to the tones produced on your digital negative output. For all you know
this curve was a VDB produced on a piece of paper towel and developed in
creek water. Nothing wrong with that except that maybe it's not your brand
of paper towel or you live on a different creek. You need to learn how to
produce your own curves. You can buy into someone's system or develop your
own as I did. For starters, get a piece of graph paper and map out where 5,
10, 20, 30...80, 90, 95 and 100 per cent black on your negatitve printed on
your final output. What you'll find is that the relationship is not linear.
Create a table from your results and make a curve based on that. This is
where understanding of the process begins.

~m
Received on Sun Nov 27 10:46:05 2005