Re: Projector guidelines

[P3D John Bercovitz <bercov@xxxxxxxxxx>]

WJC writes:
 
> I'm still on the list?!?
 
If you can certify that you are sending threats, indecent 
proposals, homophobic tripe, and filthy messages to addresses 
you acquired while a member of this list, then I will consider 
taking you off the list.  Until then, you're _stuck_ with us, 
BillyBoy!
 
Also, whoever said that photo-3d wasn't a public-forum/vehicle- 
for-free-speech per se but rather more like a publication of ETSU 
was dead on - that's how we see it at this end.  Of course we keep 
the editorial touch as light as absolutely possible (in our eyes).
There's something really wonderful about the net and that is that 
if you don't like our editorial policies, you can start your own 
mailing list.  It's simple to do and what's more, we'd be pleased 
to help you set it up.  If more people prefer your editorial 
policies, readers will gravitate to your list.  It's the law of 
the jungle and I like it!  888-)   <- my new smiley, courtesy of 
Joel Alpers.
 
>> Now isn't that [screen brightness] figure designed to reduce 
>> the flicker frequency to a point where normal movie projection 
>> rates are unnoticeable?
 
> Huh? Don't know about that.
 
I did a quick look through my books and can't seem to find a good 
reference.  Maybe Jim C can give us one.  In the area of interest, 
the ability of a person to see flicker goes with the screen 
brightness.  So if you decrease screen brightness, you can also 
decrease the number of frames per second you must project.  If you 
lower the screen brightness too much, then resolution is shot.  So 
you have to balance the two needs and that's why there are 
suggested upper and lower limits for movie screen brightness.  For 
stills, you don't have an upper limit on brightness although you 
don't want to cook retinas of course.  And that led into my 
comment on 3D projection which was:
 
>> I wonder what the brightness would have to be if the 
>> [upper limit] determining factor were ghosting instead.
 
This would establish a new upper limit, but as I said in the 
previous post, the upper limit would be situation-dependent to 
a much higher degree than in movie projection.
 
> Give it up John, dual lens systems don't work. Just say "Don't 
> dual it".
 
Until I get a Belplasca or an RBT I won't be able to say for 
sure that two lenses _really_ work but my experiences with FED, 
Kodak, Sputnik, and Edixa do give me some hope.  I think your so-
called "single lens" system (two lenses from one) works fine too, 
though.  888-)   888-)   888-)
 
John B
 


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