Long range laser projection?

[norty303]

Ok, to give it some more visual context, here are 2 shots of the most likely targets. Someone I've spoken to already reckons 1 is closer than i think, but Google maps thinks differently.
These are both from the same spot, shot 2 is basically panned round to the right from shot 1 (skipping a bit of valley). The building in shot 1 is where it'd be sited and activities centred around, and power located at (via standard Euro plugs)

[planters]

This looks good. The photo probably foreshortens, but if the projectors are located near the building, will you have any problem clearing the trees? The light rock and the steep incline and the distance of the viewers all works for you. I'm also guessing this place is REALLY dark at the location of the rock face. I also like the idea of the multiple projectors to get the power up and stay portable. I'm wondering if you can also introduce a small timing offset (I have no idea) so that a static image, like a logo, will have little or no flicker.

[norty303]

We'd probably hire some scaffold locally or similar so we could elevate. We could also site them further out onto the grass area to clear the trees. Its all fixable.

Flicker isn't going to be a problem really, the logo is 10 corners and 10 straight lines and at those sorts of scan angles we'll be able to drive even really bad scanners at 50k+

I can verify that at night, it gets very dark, very quickly, and the shadows happen real quick because of the surrounding mountains, even though you can look up and see the blue sky still above you.

[steve-o]

Yep, I'd go with the 200 Watts of lasers approach like they did

[planters]

One thing I noticed in their "200W" logo. There is not a lot of red. I just finished building up what I thought was some open can P73 diodes for an overlap experiment from the really bright beams thread. I messed up and the diodes turned out to be some left over LPC diodes. I forgot how dim these were and their tendency to go LED if you thought about them too much. Although red is still a weak color, it used to be so much worse.

[dsli_jon]

..Alright.. 'since I was asked'..

#1, this:

...I would say for a 900-1200m projection you need minimum 2x 8-10W OPSL fitted with very low divergence collimators...

..if you don't have a 'shtload-surplus of light', either via a) a Laserscope, well-collimated, ie: https://www.youtube.com/watch?v=HBxRFek-qNs, etc.. or ,b) the 'gang-bang' approach, like 'Litewave' did it, there, you could find yer projections looking fairly palid, fairly quick.. This, because, Not only do you have the 'distance vs divergence', issue, but you have atmosphere, which, like 'cloud-projection', you can't possibly 'predict'.. If the nite / area, for example, is prone to be 'muggy' / humid, your projections - even with a really-well collimated OPSL - might end-up looking 'muccky'.. Conversely, if you're gifted with a nice, clear, dry nite / low-humidity, then you will have less 'scattering' / absorbsion / crisper-projections, and less 'aerial-fx' (..which, in this case, you don't want..) Since there's not much you can 'do' about whether there will or won't be much humidity on yer gig-nite, well.. That's where having the 'metric *ton' of light comes-in..

..So, yes, I would strongly suggest you have at *least* 2x 8W OPSL, if-not a 20W'er.. Does anyone you (..or, anyone else over-there, ie: Mark H. or perhaps thru one of Briggsy's or Herr Stanwax's many giggin' connections?..) know of any Co. that might have a 20W Coherent Verdi? Or maybe a boku-Watts Jenlas Green? Or, perhaps even one of the 10W SP Millennias? (they've got, like, *insanely-low* divergence beams, like 0.5 mRad etc..) or, even a thrice of Laser Quantum 'sci-grade' 5 Watters (they usually do 2-3W overspec, all day long...).. Just some thoughts..

You should also consider 'viewing-angle'.. from yer shots, there, it *looks* like most-anyone at the 'Chalet', there, would have a pretty-decent 'narrow-viewing angle' (about +/- 25-30˚ off-center, each way, tops..) I ask, because.. IF you could keep that 'view-angle' fairly-narrow - by-means of - where you set-up yer sys / where you choose to shoot-onto, you might have a better shot of better-visibility, even with 'less-than-monster' laser-power (ie: Only 8W..) If you could, for example, position yer station *much-closer* to the visible projection surfaces - even if, say, on a bank of trees - as-long-as the viewing-angle for all the peeps was fairly narrow, you might pull-off better visibility..

ie: Here's 'only' about 5W, from, oh, about 45-50m, tops, onto *really* spikey / choppy Evergreen-trees.. (..this was a LQ 'Elite', btw.. Great-beams..)

..But, from where the audience was 'seeing this' - about another 45-50m behind where we took this shot / were projecting from - they said it was 'very visible' (..and took good shots to prove it.. Whereas, IF we'd been, say, at the 'base of the mountain', where they were viewing-from, and shooting those 100m, to that 'hill', I seriously-doubt there would have been 'as-much light to catch' on the trees, to be as-visible as it was.. Just a thought..

..But, in any-case, the Moar Powuh you can get (ie: No one, over there, has got a 'road / Tour-friendly' LS-rig? They absolutely do *not* need to be in the boat-anchor 'med-cart' format to be transportable..) If you can get yerself a 'well-collimated LS-road-rig' (shoot me an email, as-per PM, I'll 'show ya how it be-dun'.. YES, you should go for 40Ws, if ya can get it.. Especially since, watt-for-watt, the Q-sw'd KTP output will "appear" a bit brighter, than the same-Watts of CW (yes, collimation-dependent, somewhat.. because of the 'high peak-power', in the beam's pulse-train.. ie:

https://www.youtube.com/watch?v=o9Lp2I4RVBc ..approx. 700-900m 'ceiling', and this one... https://www.youtube.com/watch?v=3bRUSP5YHXw ..was absolutely-all of a 2.5-3km 'ceiling'.. Jus' sayin..

..Hope this helps.. All the best...
j

[norty303]

Interesting in your recommendation for a 'scope, as I'd elsewhere been warned off of them for this sort of application.

I'll re-iterate, for the budget, we could probably get an 8W OPSL there (and I've been told by a third party the rate is good already). So it would either happen with that, or likely not at all.

[dsli_jon]

Interesting in your recommendation for a 'scope, as I'd elsewhere been warned off of them for this sort of application.

..then that 'warning' is probably coming from someone that doesn't know how to properly collimate them for this sort of application..

..Yes, that is *LS output*

..The biggest 'advantage' you'd have, with a LS (besides the *ton of light..) is your 'projection-screen' is HUGE.. The only time you really get into 'muckky-lookin KTP-output', is when you've got a looong-throw, and, you've got a 'small screen' (like, billboard-size, from 30-40m, etc..) then the divergence, even if-good, all 'mashed-down', will make light-mud.. But, when you can 'go big', while yer 'going long', (ie, those cloud-clips..), then you can get decent 'clarity'...

I'll re-iterate, for the budget, we could probably get an 8W OPSL...

Ok, well.. If you've only 'got Budget for One-sys'.. I'd see if someone will source ya a 20W Verdi (*someone* over there has got to have one..) or a 10W Millennia, or a really-hot Jenlas.. Begging can sometimes work-wonders.. ...Or source a propery-collie'd LS..

.02, ttys..
j

[Phritzler]

Hello!
Just for reference :
2011 we done a big projection over mountains in a well known austrian ski area.
The longest distance on projections was about over 5km (not seen on the picture).
The photo was made from the facing paged mountain chain !
Some of our 15W Diodesystems (OPSL green + red/blue of our own production - specially low divergency) and some only OPSL lasersystems with 20W

In your way you should use a selected (!) 8W green OPSL with LD optics, or a really good projector with a full angle divergency not more than 0,7mrad!

All the best,
Phil

[Laserhobbit]

Norty,

Depending upon when this event is the Laser Infinity 2000 I have may also be available, I just have a few final bits and pieces to tweek and replace. Let me know if it is of any interest. Also depending when and where I have access to a couple of SP171s, if I can bother to dig them out.

Cheers

Steve