[MF3D.FORUM:1261] Re: Loss of detail in projection (wasRe:PSA Albuquerque report, Part II)

[Paul Talbot <ptww@xxxxxxxxx>]

drdave@xxxxxxxxxx wrote:
> 
> Paul Talbot writes:
> 
> > I think I understand, but I think I disagree.  You let that bully DrT
> > cloud your thinking!  ;-)
> 
> NEVER!!! *{;-)

I should have known better than to past a hasty rebuttal to anything
to David wrote...he's always a good three steps or more ahead of me
in his thinking...

> > "Which suffers more degradation, a Realist negative printed to 30x30
> > poster size, or a Sputnik negative printed to 30x30 poster size?
> 
> Why the Realist of course. But we are not comparing different formats.
> 
> > MF stereo projection, the magnification factor will be far less
> > than in Realist format projection, so the degradation should be
> > less.
> 
> Yes it will, but that holds true for the hand viewer as well. Remember
> we are comparing what the same format image looks like in a hand viewer
> as compared to being projected. If you start out with an image that is
> ten times better in a hand viewer it should stand to reason that it
> would be ten times better in projection. However the percentage of
> degradation should be the same (10% of 100 is far less than 10% of
> 1000).

You make a good point, and I see that I didn't correctly pick up on
what you were trying to say the first time.

DrT mentioned some theories on non-proportionality of magnification
versus the effects of polarizing filters, screen effect, etc.  To
add to that, I wonder whether the magnification degradation is even
linear.  It seems that when making enlargements from negatives there
is a range of print sizes within which quality is good to acceptable.
But once a certain size is reached it deterioriates more rapidly.  So
maybe the example of 10% degradation in both formats would not hold.
Does that make sense, or am I reaching for straws?

I don't know that we'll ever really be able to quantify this.  And in
fact I was hoping to hear about some observations from real life, and
hadn't really anticipated a theoretical discussion (though it has been
interesting and thought provoking).

DrT wrote:

> Perhaps I am taking this out of content but it
> does not stand to reason for me.  We've all heard the
> statement that "this slide looks better in projection
> than it does in the viewer"  Some slides look better
> in projection and others (the majority) look worse.
> So a slide that looks better in a viewer will not
> necessarily look better in projection or in the web
> or in another viewing medium.  Different viewing
> methods tend to favor different qualities in a stereo
> image.  
> 
> To tie this with MF, I agree that due to the
> lower magnification, MF slides look sharper and
> smoother in a viewer.  But sharpness is not a quality
> that stands up in stereo projection.

My whole point in starting the discussion was to try to get
a feel for the extent to which these observations, based on
35mm format 3D hand viewing and projecting, carry over to MF
3D viewing and projecting.  I'm not convinced yet that the
same rules will apply.  Those of us hoping to show projected
MF 3D slides at Buffalo could really use some insight into
this.  Without MF 3D projection systems at home to test the
images ahead of time, putting together a show could be very
much a krapshoot (anti-filter spelling).  I'm wondering
whether to shoot images that would work well in 35mm stereo
projection, or ones that would work well in a MF viewer.

Paul Talbot