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noob question about projectors...

Echo2

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Do they make a laser projector that is capable of projecting "to scale" vector graphics?

Basically....would I be able to project a graphic on to a wall with accuracy of +/- 1/16"?

Thanks for any help.

Echo2
 





Things

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Yes, laser projectors can be very accurate. You can get DAC's with 16bit XY output channels. However, you would need to determine the scale yourself as laser projectors don't really have any working "units", as it depends on the scan angle. That said, you can work it out with simple trigonometry.

Moved this to laser shows.

Dan
 

Echo2

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If I use a scale bar (little right angle ruler) to check scale.....I should be able to use software to adjust.

The problem I was having...is a standard computer projector would project at scale at the borders....but not the middle....if I adjusted for the middle...the borders would blow out.

I tried to adjust for "keystoning"....but it still would only be so close.

Do the laser projectors have an issue with keystoning?
 
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Yes, there are some keystoning effects, but they'll look different than on a regular projector. Keystoning is most visible on regular projectors because the image is projected as a plane through a lens, and that entire plane may not have the same distance from the projector lens; this can cause blurring, etc. On laser projectors, the laser beam is deflected by a pair of mirrors, so while there can be vector distortion keystoning effect due to distance, the laser dot itself rarely looks out of focus. In other words, if you're projecting a ruler on the wall, the ruler may not have consistent unit distances, but at least it'll look sharp.

In any point-source projecting system you can only avoid keystoning if you compensate for it by scaling the graphics. Even rendered 3D graphics suffer from the effect (or rather its inverse).

As for accuracy... that'll depend on your hardware. Even if your signal has a high resolution, the mechanical aspects of the galvos used for beam deflection may prevent accurate reproduction of graphics. If you really want accurate measurements you'll probably need something like a spinning mirror that is timing-accurate and then something that projects a beam at specific intervals that represent distance units. Such laser measuring tools are in a different ballpark compared to most laser projectors.
 

Echo2

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So I would probably be entering a different realm .....say if I wanted to hold 1/8" accuracy out to about 75 to 100ft

What I'm looking to do is from a fixed point....and the proper registration points.....be able to project a "to scale" pattern on a piece of equipment for repetitious layout.

I have the software end covered....and the calculations end for projector location.

Biggest issue is the projector....If the focal point of the lens was consistent....we could warp our graphic to fit....but have found if we don't set up in exactly the same place....we loose any adjustment in the warping we may have done....and it blows it all to hell.

Who would be working visible laser projection at those specs?
 
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You could try it, but I probably need a very high precision galvo system, which would be extremely expensive. It's hard enough to align beams with precision mirror mounts at those kinds of distances, let alone a high speed mirror deflector (galvo). I don't think there are many or any that could guarantee that kind of precision at those distances.

Perhaps buy an inexpensive galvo system (~$200) and see how it performs for your needs.
 

Echo2

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I was figuring on dumping a fair sum....hopefully not over $4000 to $5000 in to a good projector.

I like to shoot rifles....I know accuracy is not cheap...:)

I'll check them out...Thanks for your help.
 




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