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Re: registration (was: paper for dig...)


On Mon, 20 Mar 2000, Andre Fuhrmann wrote: 
> >When I put the printouts on top of each other I find minor differences in
> >position, enough to ruin register. But now that you mention it, the
> >register marks put in by the software program should match -- even if the
> >sheets don't.
> 
> Doubt it, Judy.  If you have reregistration problems, they are bound to be
> caused by paper shrinking.  [Just occurs to me that I may be talking at
> cross-purposes -- are you thinking of aligning colour separation?  Anyway,
> let me go on ... ] 

Yes, I'm talking about lining up the 3 color separations with each other,
which can't be done just by lining up the 3 printouts, since they don't
always fall in exactly the same position on the paper, and, as noted,
there is no room on the paper for added register marks.

 No registration method will overcome that problem.  By
> the same token, _any_ reasonable method will work provided the paper is
> preshrunk well enough.  

In that Andre, I must disagree... I have done tests of up to 8 shrinks (&
I mean soaks, not psychiatrists), including the gelatin and the hardener.
My finding is that no matter how hot and how long you "shrink," the paper
can very well continue to dry a bit smaller or a bit larger -- or in some
way a little off.  Some heavy relatively rigid papers will arrive at
"preshrunk well enough," but my tests (not yet completed) show that
changes in humidity and/or temperature, or your mood, or its mood, are
still fraught. The only really foolproof method I've found yet (and have
given the matter time, money & more than due share of what brain
remains) is to fasten to a rigid substrate, which has its own hassles.

The above incidentally, refers to LARGER THAN 8 by 10 inches. 8x10 or
smaller will hold well enough -- although that depends on the paper and
printing style or type. With digital negs in color seps you get away with
much more because the different colors are not an exact repeat, the dots
are in a different place. Also, a rough paper hides a multitude of sins...
Soft has its uses, but I want whatever I want sharp to be PERFECTLY sharp
and on the smoothest possible paper.

As for a pin register contact frame -- am moving PURPOSEFULLY toward 12 by
18 inches, larger if possible, and have a thing about paper border on all
sides. A contact frame to hold 16 by 24 -- or whatever -- would be heavy
and NOT cheap. You (James) may figure you'll start small, but that can box
you in. I've found glass on glass (plate) works well with a weight on it
for CONTACT, for *register* I still have some organizing to do (as noted).

>   I prefer a method of minimal mutilation.  All I
> need is a soft pencil -- don't even want to think of punching holes or
> pushing pins.  Case 1: neg smaller than paper -- extend 2 marks on each

I'm talking about punching holes in my printed negatives -- which deserve
whatever they get -- but aren't big enough from the laser printer without
extensions.

> corner with pencil onto the image side of the paper.  Case 2:  paper is
> smaller than neg -- extend 2 marks on each corner onto the verso side of
> the paper.  In each case, when you have lined up the neg, fix it with
> Scotch magic tape.
> 
> I prefer this method not only because it is so simple but also because I
> find it superior to all hole punching methods.  This is because in my
> experience paper always shrinks just a little bit.  In this case the pencil
> marks leave you with a choice of how to reregister: you can sacrifice a mu
> at the top or go for centering or ...

None of the above works when your 3 color seps are in 3 different places
on the paper.... however, I mention that the plastic extensions do help
hold floppy lith film straight so worth the trouble there.

But on the matter of tape -- if you don't put your tape WELL off-image it
can make your contact soft, in any kind of contact frame. Masking tape is
the thickest, hence most to avoid, but in image area any can be trouble.

Judy

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| Judy Seigel, Editor                           >
| World Journal of Post-Factory Photography     > "HOW-TO and WHY"
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