Discussion Starter · #1 ·
i see your point - we dont want something that is a perfect retrereflector only. hopefully the beads are not perfectly spherical so the light is diffused out somewhat. i would have thought the projector on the table will have more to gain than a projector placed under the ceiling in this situation.Harpmaker said:It would certainly be interesting to see how that paint worked in a screen mix. :Tcustard said:mechman said:Interesting. I was looking at something last week that I was thinking would possibly result in something like this. That stuff is pretty expensive. The stuff I was looking at would cost around $30-40 or 20-30 pounds.custard said:i have been able to locate some glass bead paint for retroreflectivity.
it can be rollered but i suppose spraying is going to give the most uniform finish.
this type of screen should only be intended for the ones who want the brightest picture on axis i think:huh:
its 1.50am here so merry xmas and i'm gonna need to sleep now otherwise i will fall asleep while eating the turkey!:yawn:
Golden glass bead gel and a matte acrylic varnish. Add that to Black Widow... just thinking out loud here. :bigsmile:yep, the possibilities are endless with what we can try...Harpmaker said:I've played around with the thought of using a retro-reflective base coat, but I think such a top coat would be too much. Also, the glass beads used would have to be VERY small; the size of the bead is what makes many screens look 'grainy'. Remember the old slide projector screens of yesteryear? I have not found a source for such small beads.
My idea was to have a translucent paint over the retro-reflective base coat.
they do say that the beads are microscopic on the site so hopefully they are small enough.
also it is water based so it should mix in with the current mixes.
120ml of the stuff is going to cost me about $30 (£20) including postage.
i'm thinking along the lines that if we are not able to remove the bright flecks with AAA-M then it may be better to introduce it in to the AAA-F BW.
to make the AAA-F lighter we need to reduce its ratio.
a 6:1 AAA-F may get us to N8-N8.5.
whatever angular gain is lost by reducing the ratio could be replaced by the glass bead paint in a retroreflective manner.
if we can keep the amount of the glass bead paint to a minimum then cost issues are alleviated - you can buy as less as 30ml for $7 (£5).
in the end if the user wants the the best option for themselves they may be willing to pay the extra amount - it will still cost alot less than the buying a commercial paint/screen with equivalent properties.
i think i will order some of the clear (120ml) and a smaller amount of the grey (60ml) for testing purposes.
My idea was that either using a retro-reflective base coat, or perhaps with the beads in the screen mix itself, the paint surrounding the beads would diffuse the retro-reflectiveness a bit to provide more gain off-axis and less on-axis. When you stop to think about it, a true retro-reflective screen wouldn't work well with PJ's since the projector is almost always mounted above or below normal viewing level.
the commercial high gain screens using glass beads get around this somehow:scratch: