Big green modules for projection: OPSL vs DPSS? ~10W to ~15W

[logsquared]

@Humphry

Have you considered using multiple projectors each only doing a portion of the graphics?

An 8w 525nm direct diode in 8mm beam can be done in 0.5mrd or maybe even better. But as usual it comes down to $$$$$. If its a 1 off event go for dpss. If it needs to last for many years i would recommend to go direct diode. Its also much more service friendly on the long run. Dpss are a pain to repair and opsl is ridiculeus expencive if its need a repair.

The only problem with direct diode is beam alignment. Not saying it can't be done, but event a small deviation makes a big deal at long distances.

[Humphry]

@Humphry
Have you considered using multiple projectors each only doing a portion of the graphics?
The only problem with direct diode is beam alignment. Not saying it can't be done, but event a small deviation makes a big deal at long distances.

Yes same page. Looks like best bet is multi 10W 532nm DPSS. Can achieve 0.8mrad with a wide beam. Also gives us better scan speeds.
I agree with you on the multi diode setup. They dont seem to pack the same beam concentration in real world tests but I know this is hugely manufacturer dependent. I do a couple of shows a month but nothing crazy on the longevity side. I would be interested to see some real image tests of side by side diode and DPSS at powers 5W+ o we long distances.

[sbk]

I would be interested to see some real image tests of side by side diode and DPSS at powers 5W+ o we long distances.

I did that a few times ago, comparing 8W OPSL with 4W 520nm diode and honestly I was a bit disappointed as the OPSL was not that brighter for projections. But it was a very quick test, not even on a perpendicular surface (lasers on tripod lighting the ground 100 meters away).
Also I have to say that I changed the focus of the OPSL, increased a bit the divergence to match other colors so not in favor of OPSL.

Though, what impressed me much more is the beam visibility in air, OPSL one was much more brighter from the side, look at the pic below (the brighter = OPSL RGBB) :

[VDX]

... did you measure the "spot"- or beam-diameter in 100m distance?

Viktor

[danielbriggs]

An 8w 525nm direct diode in 8mm beam can be done in 0.5mrd or maybe even better. But as usual it comes down to $$$$$. If its a 1 off event go for dpss. If it needs to last for many years i would recommend to go direct diode. Its also much more service friendly on the long run. Dpss are a pain to repair and opsl is ridiculeus expencive if its need a repair.

In my experience... side by side high power 532nm vs high power 520nm... there is no contest. Both are bright, but the 532nm in a smaller beam is by far brighter, sharper and the one to go for.

[danielbriggs]

It seems 10W 532nm can be done at less than 1mrad *if* you are ok with a 6mm beam. Going to ask the suppliers about an 8mm and see what we can get the divergence down to.

Some Chinese sellers struggled to get past the 4W single module DPSS design.
So for higher powers they used two smaller DPSS PBS'd together inside one module to keep the beam size small and the power higher.
Viasho used to do a really nice 8W DPSS. (2x4W internally). It was small and compact, if you removed the heatsink and bolted to a solid baseplate to take the heat away.
Beam size from memory was great... maybe 3mm, 1.5mRad or similar...? We had quite a few of these over the years. They were quite reasonably priced.

I think since they now to higher power 10-15W. Maybe look at that?

Not sure it helps: but I might have a 5W working Jenlas thin disc laser for sale very shortly.

All the best,
Dan

[sbk]

No, but divergence was around 0.8mrad for OPSL, and 1-1.1mrad for diode.

... did you measure the "spot"- or beam-diameter in 100m distance?

Viktor

[edison]

Since your budget is small i would go also for a secondhand Jenlas. Laserpower denmark has a few and also quite a few dpss lasers. You can combine them with a pbs easily to get to the power that you want/need.

[Humphry]

I think since they now to higher power 10-15W. Maybe look at that?
Not sure it helps: but I might have a 5W working Jenlas thin disc laser for sale very shortly.

Good point about the PBS design, forgot that was an option.
Thanks for the offer - 5W is a bit skinny for this project (never thought I would say that haha). But going to follow your advice and look at 2x 10W 532nm with PBS.

I did that a few times ago, comparing 8W OPSL with 4W 520nm diode and honestly I was a bit disappointed as the OPSL was not that brighter for projections. But it was a very quick test, not even on a perpendicular surface (lasers on tripod lighting the ground 100 meters away). Also I have to say that I changed the focus of the OPSL, increased a bit the divergence to match other colors so not in favor of OPSL. Though, what impressed me much more is the beam visibility in air, OPSL one was much more brighter from the side, look at the pic below (the brighter = OPSL RGBB) :

Thanks for the pics, very interesting. Your diodes look sweet as well.

So looks like like I have made my decision: ~10W DPSS on custom order with a wide beam for better divergence, and large mirrors to accommodate.
Will try to see if I can combine two with PBS instead of having them in separate projectors.

Anyone have a contact for Vaisho? I cannot find their website.

[sbk]

Anyone have a contact for Vaisho? I cannot find their website.

Honestly, I wouldn't advise you Viasho. I had quite bad experiences with the reliability of their 4W heads in the past (and far from being the only one), though the beam was of good quality... If you wanna invest, invest into something that will last long (good quality diode or OPSL), so all the hard earned cash will be for you rather than wasted into bad hardware repair