Re: [Leica] Enlarger height and enlarging lenses

[Ed Buziak <ed.buziak@camera-and-darkroom.co.uk>]

Bob,

It might be prudent do another test to check focusing error and sharpness...
assuming, that is, you have your enlarger perfectly aligned.

Basically, focus the projected negative image on the baseboard, check it
with your Peak/Micromega and expose a piece of paper.
Without altering focus on the lens or lens stage raise the enlarger head 3mm
and expose another piece of paper.
Repeat the exercise another 3mm higher...
Do the same for 3mm lower than the "correctly focused" height
Repeat another 3mm lower.
It's best to repeat this until you have test exposures from, say, -9mm below
through to +9mm above the "correct focused" distance.

Then process all the tests, dry them and look at them carefully. Pick the
crispest, sharpest test print and look at the data on the back to see which
it was. There's only a so-so chance it was from the "correct focus"
position!  8-0

Ctein has written about this "focus shift" problem with certain VC papers in
C&D and PhotoTechniques and it sure surprises a lot of folks when they check
their own set-up. His findings make a mockery of the old stand-by of placing
a sheet of paper under the focus finder to help focus correctly.

And stopping down to f/11 or f/16 (from f/2.8 if you're using a 50 Componon)
is 2 to 3 stops more than necessary (try f/4 to f/5.6 and you might be
pleasantly surprised) and is not only going to degrade your best efforts,
it's going to extend your enlarging times unnecessarily too... adding
associated problems of enlarger vibration and negative "popping".

I'm no technical expert so I can't go into the why's and wherefore's of all
this... I've just practiced basics and simplistics for the past 35 years...
and, it works. Mind you, I do use a longer lens on occasion despite knowing
that I'm losing out theoretically... my Durst Multigraph gives 0.7 second
exposures two stops down with 5x7 prints so I have to fit the 150mm
El-Nikkor to give workable 3-6 second exposures... and if I require longer
times than those I use 52mm Nikon ND filters to screw onto the 150 (they
have the same thread).

Ed Buziak / Publisher
"Camera & Darkroom"

ed.buziak@camera-and-darkroom.co.uk

* Web site under construction *

- ----------
>From: rlb <rlb@triad.rr.com>
>To: leica-users <leica-users@mejac.palo-alto.ca.us>
>Subject: Re: [Leica] Enlarger height and enlarging lenses
>Date: Mon, Feb 28, 2000, 3:46 pm
>

>Most of my prints are made at F11 or F16.  I am going to back down from this
>and start printing at F8 or less just to see.  I use the very expensive Peak
>grain focuser and I am going to look at the grain at different f stops to
>see if I can tell a difference.