Gasoline thrown in the campfire and burning 3-D images!

[P3D Gabriel Jacob <jacob@xxxxxxxxxxxxxx>]

Jon Golden writes:
>Brad, As I said before....white reflects...black absorbs...I think you'll
>find the solution here.

Larry Berlin writes:
> If your slide mounts have a black side and a white side, that's EXTREMELY
> POOR DESIGN for ANY slide holder regardless of which projector you may
>use. Throw them out! If you need a system for distinguishing front from
>back, some simple marking is much better than endangering your slides with
>basic heat absorption from accidental misplacement in the projector. A
>basic solution would be to only use mounts that are white. Aluminum mounts
>would be ideal for hotter projectors. It would also be a good idea to add
>ventilation fans to any projector that seems to get too hot. Surplus 
>stores sell fans pretty cheap.

Gary Nored writes:
>Stuff and nonsense! I use black/white RBTs, black side to the lamp. 
>They come out of my TDC 716 with twin 750 watt lamps still cool to the 
>touch. I don't see how, but fact is, they just don't get warm. Of
>course, I never leave one in for 10 minutes either! If the audience
>didn't fall asleep, I would.

Finally Gabriel writes:
Boy never thought my mis-spend years as a youth would help in the above
dilemma. When I was a young lad I would pass the time with my trusty
magnifier (I forget the focal length it was) burning things. I enjoyed
burning paper, wood, and melting plastic stuff. Even VM. Anyways what
I found out was that after determining the proper focal length of the
double convex lens. Then adjusting it to get the sun rays focussed on the
combustionable material was that, black burns better than white!
Yes years later in my college years I would find out the reasons for
this mysterious phenomenon. I won't bore you with the details of why
this is so except that it has to do with black body physics and
electromagnetic radiation. All I will say is that a black body is
a good absorber of radiant energy or for the sake of brevity heat
radiation. This is why I had so much fun burning black paper as opposed
to white paper. White paper is a poor absorber of radiant energy and
reflects most of it back. Now for the thing that puzzled me in school.
They told us that black is a good emitter of energy also! How can this
be I pondered? Well it seems that it is a good emitter of energy ,not a
good reflector of energy. If it is emitting or absorbing energy depends
on the nature of the body and the difference  between its temperature
and the surrounding temperature. Now I am coming to the conclusion of
this long winded post.
RBT mounts were made white on the side that faces the light so that it can
reflect the radiant heat. Now why is the other side black? It seems (and
I am only guessing here) whatever little energy is absorbed from the white
side can be more efficiently emitted if it is black! Since the temperature
difference between the white side and black side is greater on the white
side, the black part will radiate instead of absorb.

Now my question is. What is the proper way of mounting RBT's and why
would someone mount the black side facing the lamp. What is the correct
proceudure, or isn't there any? Secondly plastic or paper mounts would
feel cooler to the touch compared to aluminum or glass mounts. ;-)

Second question. What kind of projector did Grant Campos actually use?

Third question. Gary do you have any relation to the Nord projector? ;-)
Finally got one and works great. No thanks to another individual who
gave his word twice on a TDC 116 (among other things) and never delivered
the goods. He will go nameless for now.

P.S. Okay I expect to see more traffic here on P3D next week. Yes I know
it was Thanksgiving and people were travelling to loved ones on one of
the busiest travel weeks in the year. But don't forget next week is 3D
day. So lets see some interesting stuff for 3December.

Gabriel




------------------------------