Anti-newton Rings

Newton rings are those colored irregular circles you may see when two smooth surfaces are in contact. Film touching glass is the situation most lab workers ask about. The common advice is to use anti-newton ring glass in the negative carrier. Alternate methods: control humidity (to around 40%) — use a spray such as odorless hairspray, use oil carrier, use talc powder.

So, disrupt the surface by making one of them less smooth. That’s the general idea; workable if you are using only one piece of film, however, in a mask stack you will have more than a single piece of film. These two sheets of film may have newton rings if placed back to back, or if one has a smooth emulsion layer. 40 years ago in labs we didn’t see this with Sep Neg type 1 (or 2) and Pan Masking film because Kodak had solved it with design of the emulsion. Now only Kodak Professional Tri-X 320 has the surface tooth; there for retouching — this film isn’t the best solution for masks or separations, alas.

Some possible products, or items to use to cut down on Newton rings. AN glass is available widely. It isn’t rare although reading the forums it seems to be lost and gone.

Some chemicals used in those anti-newton cans of the past: cerium oxide; STAYBELLITE ESTER.

Offset press powder consists of vegetable starch.

One supplier: https://stargraphicsupplies.com/categories/pressroom-supplies/spray-powder.html

Or, try SX 2001 Scannex Anti-Newton spray from: http://www.aztek.com/Products/Aztek%20Imaging%20-%20Scanning%20Supplies(main).htm

There is a patent on using spray to control newton rings which offers some advice along with a description of the problem. https://patents.google.com/patent/US4575398A/en

Lost in the weed

follow experts so lost in the weeds they'd have you using an industrial weed wacker to clear a 0.09 acre yard.(not enough room for a tennis court)

References from the Golden Age of petrochemical photography.
Camera technique for Professional Photographers, Kodak Publication No. O-18
Large-Format Photography, Eastman Kodak Company Publication O-18e. ISBN 0-87985-771-4

Stroebel, View Camera Technique
https://archive.org/details/viewcameratechni00stro

Kodak 1952, Camera Technique
https://archive.org/details/cameratechniqueforprofessionalphotographers

https://archive.org/details/basicdeveloping00east

https://archive.org/details/kodak-films/page/n19/mode/2up
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* Type of camera
* parts of camera
* film holder / use
* lens board / mounting
* focusing / aids
* exposing
* processing
* printing
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approach. mode. photography changed in need and use, users
pedagogical mannerisms. 
ask those who told you about focus rules, why those rules fail with movements.
what you are asking, simply, is: how to focus a view camera. Answer is based upon the scene and the seeing.
everywhere or selective somewhere