DiY Retroreflective Green/Bluescreen

[Cody Deegan]

I think the problem may be that I just soldered everything without taking into consideration that an LED has a + and a - side. 

Ha, ha - I'm so cool I can't stand it.

[Cody Deegan]

Hey Dino, thanks for the motion capture idea.  That's something I've always wanted to try.  This opens up all sorts of new possibilities.  I seriously never would've thought about trying this if you hadn't shared the idea.

[Cedric Akins]

Hey Cody that new doohickey looks very well put together. Great going. I believe I will get one put together sooner or later. I am still fine tuning my version of the Skater Mini dolly. You can find it in the dolly section. Oh by the way did you ever find a place to get the reflective material at a reasonable rate?

Cedric

[Cody Deegan]

I tried out the reflective paint.  This stuff comes with two extra cans of glass beads.  I am finding out that the trick to getting it to work is even coverage of the surface, as you can tell from these pics.  The paint is uniform, but my scattering of glass beads is not.  There are extreme hot spots in some areas and dull spots in others.  I also don't like the green light from the LEDs spilling onto the foreground object.

[MikkoWilson]

Well cody, i'm sure you are aware that LEDs only work one way round.  (After all, they are a Diode [Electronic one-way-gate])
One LED in backwards will prevent an entire group (all LEDs in series with it) from operating.  - Check to make sure you don't have any backwards.

And yes, too mcuh heat can burn up anything, but it's preaty rare with LEDs.

 - Mikko

[Dino Zizzari]

Ok, I've found footage with first tests i made with my LED-Ring prototype and the scotchlite fabric (only 4  blue LEDs!!). Camera was about 3 meters away.
Keyed with Premiere Pro standard-keyer (no spill or edge correction).

Dino

[David West]

verrrrrrrrrrrrrrrrrrrry   impressive.....

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on the budget ideas----

Cody,
do you have any thrift shops near by??/

there are often old movie projector screens to be found....  these have a UNIFORM highly reflective surface.... perhaps that would work instead of the 300 dollar screen....

just a thought....

[Cedric Akins]

Holy Cow . You got that result with only 4 LED's at 3 meters? That is incredible. I can't wait to start building one. I think I have a few resistor around here somewhere. I believe I will find an old projector screen first. The other stuff is pretty reasonable.

But Dino how did you turn off the other twenty LED's? You said you were using 24 LED's in groups of 6, right?

Cedric

[Dino Zizzari]

But Dino how did you turn off the other twenty LED's? You said you were using 24 LED's in groups of 6, right?
Cedric

I made this test bevore I start building the ring - just for looking how good the scotchlite material is. And it's goood!

The 'key' for build a good retroreflective bluescreen is to use a real (retroreflective) screen. a projector screen is reflective but not retroreflective and will not giving the result you want.

Dino

[MikkoWilson]

Wait, i think i missed where someone said where to get that Paint and the Beads.. Where?

- We have a Real Holoset (Refelctmedia) setup at my College . we have the large Green lightring and 3 of the large peices of the fabric.. it'd be awsome to be able to paint props too!

- Mikko

[Cody Deegan]

It was a good idea, David - thanks.  I just tested it out and I think - like Dino said - the effect just isn't quite right.  It just wasn't near as brilliant as his blue test.  At first I thought maybe my LEDs weren't bright enough.  The coverage was even but very pale.

Dino, where'd you get your material at?  I was thinking about calling 3M and getting some price quotes because I cannot find a distributor.

Mikko, just go back to the first page of this topic for the paint link.  So far though my tests with it have not yielded very good results.

[David West]

thanks for testing it Cody.... i was hoping that we could get by with the affordable solution.....
i too would be interested in where to purchase the REAL fabric.....

[Dino Zizzari]

I found my material at the swiss-army-auction. They had a large stock of this material used for manufacturing security vests for the army-police and gave the rest in the auction.

I spoke with a guy at 3M, they would give me the Scotchlite 9910 material for 90 SwissFrancs (~60$) per meter.

Dino

[Dino Zizzari]

Ok, I realized that you won't believe that the testshots are made with only 4 LED's.

So, I made some pictures with my digicam and my blue LED-lenser..
- Camera -> Screen ~7 meter
- Daylight (3 windows)
- Shot indirectly (mirror)

Pics:
1. with flashlight (very reflective)
2. hotspot because only 1 LED
3. distance ~2m very low-angle LED
4. simple setup - 1 LED, digicam, mirror, screen

Cheers, Dino

[Kevin Clark]

Good info Dino... Thanks.

Cody, David, et. al. I talked to a few discouraging distributors today to try and get some Scotchlite pricing.  I was quoted $75, $90 and $100 a yard by 3 diffrent distributors with a 50 yd. min. for the 9910 material. You'd think this stuff was spun with gold or something.

After talking with the one guy and splain'n the application he said the 8910 is really the same stuff only a little thinner backing material than the 9910 which is made for industrial use. He said I could get the 8910 for $50 per yd. with a 25 yd. min. Which is $1250 for 25 yds. x 50" or a total of 312.5 sq. ft.

I'm still looking for someone that would sell me about 6-10 yds for a reasonable price but no luck yet. If there are say 3-4 people interested maybe we could split a roll or something if no better deal surfaces. Just a thought.

Kevin