Make Project's DIY Glass bead high gain screen - AVS Forum
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post #1 of 3 Old 04-28-2012, 01:49 PM - Thread Starter
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I did some searching and didn't spot this but it might have gotten some play last year

http://makeprojects.com/Project/Glas...n-Screen/685/1

Make projects used the glass beads from Harbor Freight and for way under a $100 made a really nice high gain screen. I haven't tried this myself but for those use led pjs (and other low lumen pjs) this might be something to consider making





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post #2 of 3 Old 04-29-2012, 01:07 PM
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Hi Victor!

Yeah...we've discussed this application before....quite some time ago in fact. The general consensus was the the diameter of the Glass beads were about 3x larger than optimal for the application. Besides, the Author could not really show (...or prove...) that the Image Quality and texture of the screen was really something that was overall desirable or effective enough to really make it stand out as a undeniable success.


Do take note that due to the specific PJ placement issues such screens present, how very high up toward the ceiling the Screen had to be. And the images shown also do not show any comparisons as to how degraded the brightness becomes when viewing from each side, nor how bad brightness drops off when viewing the image from a lower elevation (viewing height) than normal. I can say without hesitation that anyone sitting in a chair of normal height would take issue with that, with the screen shown being as high as it is.

Now if the darn thing was substantially bigger...that might help a bit, but even then the retro-reflective tendencies would create a noticeable difference between the Center of the image, and the Top/Bottom/Sides

Even so...it does go a ways toward showing that such projects are in fact "do-able", and tosses the adverse comments made by a select few that it is / was patently impossible to create a "DIY High Power" Glass beaded screen right back into their laps.

To quote James T. Kirk;
"I'm laughing at the superior intellect"
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post #3 of 3 Old 05-02-2012, 06:03 PM
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I used a quick search and found a blast media/grit size conversion table here:



80grit ~ .0065" / 3 = .002167"

.002167" would roughly approximate 240 - 280 grit blast media. Of course, these are just simple calculations and do not speak to the feasibility of actually applying the material in an effective manner.

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