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Re: Wet Gates



Dear Jeff and Rob,

The use of wet gate printers in a lab really depends on what the customer is
trying to accomplish.  We've got four wet contact printers (Petersons and one
Hollywood), plus some custom-made wet gates for our two Bell & Howell step
printers.  So you could say there's quite a bit of interest in wet gate
printing, and we do a lot of it nowadays.  Of course we also have dry
printers, so that hasn't gone out of fashion yet either.

>we found that liquid gate printing made a very big difference in terms of
>"lushness" and "creaminess" -- stuff that was hard to quantify, and things

My understanding of why liquid gates for telecine and for film printing yeild
a different look may is based on refraction.  Refraction occurs whenever
light passes through a boundary between transparent substances on an angle;
as the light transmission speeds of the substances differ, the angle of the
light changes.  If you consider what happens inside the film when it is
illuminated, refraction can occur  where the light leaves the film.  A small
portion of that light ends up bouncing back into the film, effectively
causing a spreading of the light, which then changes the overall look of the
image.

In a wet gate set-up, the fluid becomes part of the optical transmission
path, and since its incidence of refraction is much closer to that of film
than air, far less light ends up re-illuminating the film.  I suppose you
could call it a "thick faceplate" for the film, though a thick faceplate on a
telecine tube is certainly *not* the same as a wet gate!

Regarding perc in your CF2, it is definitely not recommended by
Lipsner-Smith.  Perc evaporates more slowly than trichlor, so you'll have
drying problems.  I suppose it would be possible to mod a CF2 to use perc,
but it would probably have to run so slow that it wouldn't be worth using.
 You might consider redistilled trichlor, which is still available for a
price, as a stopgap.  (The current laws only ended the manufacture of new
trichlor, not the recycling and reuse of whatever is still around).

Finally, I'd like to remark that perhaps your local officials don't have a
great attitude towards Federal regulations, but it's still worth taking
proper precautions when handling and using perc. Unlike trichlor, the stuff
is on the list of potential carcinogens, and it has other detrimental effects
on health and the environment besides.  

Christopher Bacon