Looking for grainless plastic sheet

I'm looking for thin (ideally .010 or even thinner) plastic sheeting
that's semi opaque/translucent - sort of like "milk jug" color, or
maybe tending toward white - but with very little or ideally NO visible
grain or striations, a completely even looking color/texture.

As a comparison, very thin sheet mylar such as a graphics shop might
use to print on is in the right neighborhood, but still has a small
amount of grain. This is for rear projection of an image and I don't
want any grain visible.

Is there sucn a thing? I don't need a lot, probably a square yard, but
realize I'll possibly have to buy more than I need due to the
non-feasability of selling small quantities.

Thanks for any info.

I'm looking for plastic sheeting for rear projection
... Mylar such as a graphics shop might
use is in the right neighborhood, but still has a small
amount of grain. This is of an image and I don't
want any grain visible.

Is there sucn a thing?

No.

Your best solution is to buy a foil made for rear
projection. See B&H. This is an old problem, has
been well analyzed and the products made for this
purpose are the best you will do. Try DaLight, Elite,
Draper etc.

The matte surface of drafting Mylar is there
so you can draw on it, it is not there for optical properties.
A rear projection screen has a surface made for optical
scattering, not graphite adhesion.

Holographic rear projection screens have become a
reality recently and you may want to explore this
avenue. Last time I looked a small screen
was ~$2,000.

For conventional screens it is the grain that makes a
rear-projection screen work. Each 'grainlet' works as
a small prism and sends a little bit of the light in a
skew direction. Enough grainlets and the light is evenly distributed.

In general, the finer the grain the dimmer the image: each
grainlet wastes a bit of the light and the finer the grain the
greater the waste. A very fine screen has a very dim off-axis image.

A grainless screen would be a sheet of clear glass: no off-axis
image but a hell of a hot-spot.

There are techniques using a combination of acid-etching and
fine grinding that give a very fine grain yet high efficiency
diffusing surface on glass. Regular ground glass is made with
grinding or sandblasting and the resultant surface is not
optimum for optical use.

You can find what looks like a whitish grainless drafting
Mylar but what you get is opalescent plastic with the same
matte surface. This solution may give the appearance of
no grain but the image will be diffused.

--
Nicholas O. Lindan, Cleveland, Ohio
Consulting Engineer: Electronics, Photonics, Informatics.
Remove blanks to reply: n o lindan at ix . netcom . com
f-Stop enlarging timers: http://www.nolindan.com/da/fstop/

Try these folks...ain't google grand!

http://www.da-lite.com/products/index.php?cID=10


wrote in message
ups.com...
I'm looking for thin (ideally .010 or even thinner) plastic sheeting
that's semi opaque/translucent - sort of like "milk jug" color, or
maybe tending toward white - but with very little or ideally NO visible
grain or striations, a completely even looking color/texture.

As a comparison, very thin sheet mylar such as a graphics shop might
use to print on is in the right neighborhood, but still has a small
amount of grain. This is for rear projection of an image and I don't
want any grain visible.

Is there sucn a thing? I don't need a lot, probably a square yard, but
realize I'll possibly have to buy more than I need due to the
non-feasability of selling small quantities.

Thanks for any info.

Nicholas O. Lindan wrote:


In general, the finer the grain the dimmer the image: each
grainlet wastes a bit of the light and the finer the grain the
greater the waste. A very fine screen has a very dim off-axis image.

A grainless screen would be a sheet of clear glass: no off-axis
image but a hell of a hot-spot.


I appreciate the info. I should probably clarify that what I want to
use it for is projecting/capturing movie film. I've actually found a
couple of materials that yield decent results but I can still detect a
bit of grain in the resulting image, wondered if there's any way to get
rid of it altogether.

You mentioned grinding/etching glass, I had tried using 1500 grit
wet/dry sandpaper on the mylar to see if I could cut down the grain, I
don't feel it made a noticeable difference.

Nicholas O. Lindan wrote:
I'm looking for plastic sheeting for rear projection

A very fine screen has a very dim off-axis image.

P.S. and because of what I'm using it for, off-axis image isn't a
consideration.

wrote:
Try these folks...ain't google grand!

http://www.da-lite.com/products/index.php?cID=10

I'd seen this before posting, but not quite what I'm looking for.

wrote

I appreciate the info. I should probably clarify that what I want to
use it for is projecting/capturing movie film.

Then you don't need a screen at all -- project the film right
on to the sensor chip or dup film.

After all is said and done I think it would be cheaper to send the
film to a transfer service than trying to cobble something together.

Nicholas O. Lindan wrote:
wrote

I appreciate the info. I should probably clarify that what I want to
use it for is projecting/capturing movie film.

Then you don't need a screen at all -- project the film right
on to the sensor chip or dup film.

How would this be accomplished? Wouldn't doing so mean I'd have to
reverse the image with software?

After all is said and done I think it would be cheaper to send the
film to a transfer service than trying to cobble something together.

Well, of course there's the issue of wanting to do it myself. Further,
I only need a small amount of whatever material this would be. I
already have a rig "cobbled together" and have gone to a fair amount of
effort to do so, but I find the weak link in the chain is the
projection surface. What I have now doesn't look unwatchable, but I
feel it could be better, and given my disposition, I'm inclined to
pursue that potential.

wrote:
I'm looking for thin (ideally .010 or even thinner) plastic sheeting
that's semi opaque/translucent - sort of like "milk jug" color, or
maybe tending toward white - but with very little or ideally NO visible
grain or striations, a completely even looking color/texture.

As a comparison, very thin sheet mylar such as a graphics shop might
use to print on is in the right neighborhood, but still has a small
amount of grain. This is for rear projection of an image and I don't
want any grain visible.

Is there sucn a thing? I don't need a lot, probably a square yard, but
realize I'll possibly have to buy more than I need due to the
non-feasability of selling small quantities.

Thanks for any info.

Can you find an old rear projection TV at the junk yard, E-bay or garage
sale?

just a thought...

Gregg

"Gregg" wrote

I'm looking for ... rear projection [screen]

Can you find an old rear projection TV at the junk yard, E-bay or garage
sale?

Now _that's_ a good idea!