P3D Re: PHOTO-3D digest 3151

[michaelk@xxxxxxxxxxx (Michael Kersenbrock)]

> Hi folks! I have a couple of questions that I want to throw out to the group
> for answers. #1 What are Newton Rings? 

It's what you get when you leave a figbar on the counter for a month or two.

> I have a couple of boxes of RBT mounts
> with anti-Newton glass, I thought that the glass was to reflect heat away from
> the film chips, however I noticed a reference to "Newton rings" on the RMM
> slide mounting tutorial. This leads me to believe that I have no real clue
> about this phenomenon. So I stand by to be educated. 

It's a light interference pattern that might be caused at the interface of
flat glass and the flat film surfaces up against each other.  The anti-Newton
glass has surface irregularities (small to you and me, but large on a
light-wavelength scale). That keeps the two surfaces apart.  So if the glass
is anti-newton'ed on only one side, it'll only work one way (RBT's glass
is this way I recall).  Some if not all of the metal-mask mounts that get
mounted inside glass have bumps in them such that the glass and film don't
actually touch each other, and this gets rid of the rings that way.


> #2 With regard to those
> RBT mounts, I get the distinct impression that film should be mounted
> differently depending upon whether the slide is to be viewed via a projector
> and screen as opposed to a stereoscope type viewer. In other words with the
> stereoscope it seems as if the black portion of the mount which defines the
> stereo window should be facing the person viewing the slide. But if I intended
> to project this image then the film chips would be upside down and backwards
> in the mount as compared to the first example? Again I stand by to be
> educated! Hope everyone had a merry Christmas and is enjoying the new year!

I always mount with the white side toward the viewer (or projector bulb).

Some have voiced objections to this in viewers (as perhaps you do),  but it hasn't 
caused me any grief personally.

I mostly get confused as to which corner the dot goes to help the
projectionist (is this standard, or only in our club?).

Mike K.



> Respectfully submitted:
> Mark Hatfield
> 
> 


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