Blue monster project

[heroic]

Yes, I realise that the beams are overlapped.

1.5mrad will work out to more than 15mm at 10m if I'm not mistaken

Assuming zero beam size at the laser:

1 rad = 1 m @ 1 m
1 rad = 10m @ 10 m (by definition)

.'.

1.5 mrad = 1.5 mm @ 1 m
1.5 mrad = 15 mm @ 10m

[dave]

I'm not thinking too quickly today

[aijii]

Doc - we use two 1 watt 635nm lasers in our 4W (soon to be 5 or 6W) RGB. These by no means make a small tight beam, i'd estimate 4 or 5mRad. We've matched the green and blues "approximately" to the same size of the reds, but there is still red over hang.

Having said that, the effect is barely noticeable when audience scanning, the fat beams look cool, are safe, and overall the laser still LOOKS like 4 Watt, regardless of how fat the beams are.

Has anybody actually seen what 24W of 445nm looks like in the sky ? the raw output from the diode block in the projector, with shit lenses, is pretty damn impressive on a clear night, let alone a foggy one.

Can't wait to get 20 or 30 diodes beaming a lot closer together...

A pair of 20-30W blues would make good partners for our 2 laserscopes.

[mccarrot]

Like (i think) Dave said, not too many people are going to want to or need to do graphics with >20W or >30W of laser light. 20-30W is orgasmic though for some outdoor beam stuff. And for that, who cares about beam quality?

-Marc

I find Outdoors beamquality is more important than inside.

If you use a 5 mRad laser indoor it will look ok if your venue is not too big, but outdoors (normally bigger area) a 5 mRad beam will have a 0,5 METER diameter spot after 100 meters! this 50cm beam will completely look washed out and will not look like a laser anymore.

So in my opinion the larger the area the more important beam quality gets.

[andy_con]

I find Outdoors beamquality is more important than inside.

If you use a 5 mRad laser indoor it will look ok if your venue is not too big, but outdoors (normally bigger area) a 5 mRad beam will have a 0,5 METER diameter spot after 100 meters! this 50cm beam will completely look washed out and will not look like a laser anymore.

So in my opinion the larger the area the more important beam quality gets.

i kinda dropped out of this thread as not many shared my view.

but im glad im not the only one thinking this mccarrott.

why do coherents lasers look so bright outside? cos their beams are so bloody tiny.

[Doc]

^^^ So in conclusion (hopefully); it totally depends on your planned usage.; I bought negative lenses to deliberately diverge my projector.

For the venues I operate in (circa 1600 capacity max) everything is good, for big venues a tight beam would be needed. ^^^

[Diachi]

Can't use more than one cube. It reflects one polarization of light and passes the other, so if you try to use a second one half of your power will be lost through that and you'll be back to where you started. The best way to do it would be to use the knife edged mirror method.

[mccarrot]

24W of blue and a scope would be on my list of things to do.

than first go back to school and learn about physics

[Laserman532]

What takes most people a year to learn usually takes me 1 month....

[badger1666]

as you have explaned it ,this can't be done .period... with a pbs cube two beams has to equal + as a beam not this - , go read up on laser physics and polarisation and stuff
should only take you a day or two

I never hear too many answers about actually lining beams up from 24 diodes....I would try it like this as I think it can theoretically done.

24 diodes through 12 PBS cubes with EACH strip going DIRECTLY through each other to make one stripe only....no squares just one perfect line....then worry about beam correction afterwards.If beams diverged too much before hitting the next PBS...correct it.
Stuffing big set up with usual but not too much excess losses.I still dont know why can use a convex and concave lens to narrow the beam if you want.

With the aixiz 405 lens my beam looks pretty dam good going into the night sky right next to my green(very good in fact even if i walked 300m down the road!)24 of those with a perfect tiny same strip.....

24W of blue and a scope would be on my list of things to do.