minimum print time test

i found a problem when do the minimum print time (MPT) test. i did the
test use a clean negative to cover half opening of the negative
carrier. then using diefferent exposure time ( 2s, 4s, 6s ... ) to
make a serial of strip on the paper.

after developed and dry the paper, i then try to find in what print
time i can not tell the difference in black between two strips in the
film side of the paper ( the paper is divided into 2 sides, because the
film covered only half of the carrier ). actually, i found the 16s
looks with same black with 18s strip ( that meas i can not tell which
is which ). by this, i think my MPT should be 16s.

but the problem is, the 16s strip is still not as black as the clean
side of the paper. there exists a little difference. but, from 16s
on, the clean side of the paper goes really very black so i actually
can not tell where is 18s where is 20s. i just saw that in some strips
longer than 16s, the film side and the clean side come to totally same
in black.

my question is, should i use 16s as my MPT?

thanks.

-
woody

Yeah, whatever you want. That's close enough. But you can't be sure your
development is so very perfect to make that base line perfect in every case.

Just doing a normal test strip when enlarging is what you really need to do.
There is no base 'normal' for creative printing.

Get over the metrics and make prints.

Dnia 9 Aug 2006 19:24:40 -0700, Steven Woody napisa³(a):

my question is, should i use 16s as my MPT?

Yes - even if you (theoretically) get "full" black at 30s it
makes no sense to use this time, because you get no visible
details in shadows (you wrote that you see no difference 16s).

Greetings,
Henry

"Steven Woody" wrote in message
oups.com...
i found a problem when do the minimum print time (MPT)
test. i did the
test use a clean negative to cover half opening of the
negative
carrier. then using diefferent exposure time ( 2s, 4s, 6s
... ) to
make a serial of strip on the paper.

after developed and dry the paper, i then try to find in
what print
time i can not tell the difference in black between two
strips in the
film side of the paper ( the paper is divided into 2
sides, because the
film covered only half of the carrier ). actually, i found
the 16s
looks with same black with 18s strip ( that meas i can not
tell which
is which ). by this, i think my MPT should be 16s.

but the problem is, the 16s strip is still not as black as
the clean
side of the paper. there exists a little difference.
but, from 16s
on, the clean side of the paper goes really very black so
i actually
can not tell where is 18s where is 20s. i just saw that
in some strips
longer than 16s, the film side and the clean side come to
totally same
in black.

my question is, should i use 16s as my MPT?

thanks.

-
woody

Its difficult to reach the actual maximum black of any
paper with normal printing. The difficulty is that an
exposure great enough to reach maximum black may result in
an overly dark print, or, if contrast is increased, an
overly contrasty print.
As long as the blacks are fairly deep the eye will
accept them. The best prints are made by finding the
exposure and contrast that result in good looking mid gray
tones, something you can judge by eye.
Personally, I find excercizes such as finding a minimum
exposure both a waste of time and misleading.


--
---
Richard Knoppow
Los Angeles, CA, USA

Steven Woody wrote:
i found a problem when do the minimum print time (MPT) test. i did the
test use a clean negative to cover half opening of the negative
carrier. then using diefferent exposure time ( 2s, 4s, 6s ... ) to
make a serial of strip on the paper.

after developed and dry the paper, i then try to find in what print
time i can not tell the difference in black between two strips in the
film side of the paper ( the paper is divided into 2 sides, because the
film covered only half of the carrier ). actually, i found the 16s
looks with same black with 18s strip ( that meas i can not tell which
is which ). by this, i think my MPT should be 16s.

but the problem is, the 16s strip is still not as black as the clean
side of the paper. there exists a little difference. but, from 16s
on, the clean side of the paper goes really very black so i actually
can not tell where is 18s where is 20s. i just saw that in some strips
longer than 16s, the film side and the clean side come to totally same
in black.

my question is, should i use 16s as my MPT?

thanks.

-
woody


The other thing about the "minimum exposure time to yield true black
contact print thingy" is that it works best only when you are exposing
your film for the maximum EI using ".01 over film base + fog" (or
whatever). If you like a negative with more shadow detail and routinely
expose your film at a lower EI all of your contact prints will be too
light.

It makes more sense (to me) in a commercial studio/lab where time is
money and a lot of work is produced without test prints. And it made
sense (to me) in the days before I had my own densitometer to evaluate
"true EI" vs. published ISO when testing a new film against old "tried
and true" (whatever that was that year).
--
darkroommike