Advice Please

[A1XD]

Hello every one
I would like some advice as I'm new to lasers and professional laser specs. Im struggling to get a decent white beam from my lasers. Instead of a nice white I'm getting more of a magenta / white, almost like the RED is over powering the full RGB mix.

I'm using quickshow and i do understand the colour settings etc so I'm wondering if the spec on the laser is wrong for a decent white beam. I would of thought 2.5W would produce some pretty spot on colours with the graphics and beam shows quckshow offers.

The laser is analog and this is the spec

LKH Pure Diode 2300RGB 2.3 Watt Pure DiodeBeam Power:
RED: 650nm 200mW + 638nm 180mW
GREEN: 520nm 120 mW
BLUE: 445nm 1800mW
Beam Spec: 5.6mm <2mrad
Laser Class: 4
Scanner Speed: 20kpps (40Kpps@4˚), 40˚ for scan angle Max

Any advice on unit adjustment is welcome

Thanks in advance

Alex

[buffo]

Based on the numbers you listed, you have way too much blue for a good white balance. You only need about 300 mw of blue at maximum, based on the amount of red and green you have. You've got 6 times that amount. This is rather common with lower-end projectors, as blue is cheap and having lots of it allows a company to advertise the projector as a 2 + watt unit when really it's only ~800 mw when producing balanced white.

However, you said that the white looks red-heavy to you. This doesn't makes sense based on the power levels you listed, unless the red beam diameter is significantly larger than the green and blue, in which case having a red "halo" around everything will tend to make it look more red-heavy even when it's really not.

Post some pictures of the projector drawing a simple white shape on the wall (circle or square or something).

Adam

[A1XD]

Adam

Thank you for taking time to reply to my questions.
I will upload some photos of the lasers when i get a chance. Your comment about the RED "halo" effect is spot on tho.

Thanks again

[A1XD]

Some photos of the laser.




The last photo shows the units in question with a 3W in the middel

[Bradfo69]

The fact that some of your red is the 650nm wavelength may have something to do with the halo, as the beam diameter of 650 is going to be much larger than anything else in the projector. But yes, that's awfully magenta...
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I'd play around with some software settings first to see if you can improve it and I'd be a little inclines to pop the cover and see if something isn't preventing all of your green to come through. Maybe something slightly out of alignment - or hugely.

[A1XD]

Hi Bradfo69

I will have a go at balancing out the colours in quickshow before i take the lid off. I'm sure I have been through the process correctly before on quickshow, but visually I do not seem to achieve a great deal.

I thought the lasers would of been a good starting point, but i have been disappointed by them so far. I went for these over the laserworld units that had a similar spec. they looked not to bad but heard bad reviews on build quality

[Bradfo69]

I'm going to assume that there are no adjustments on the back of the laser for individual power of the diodes. I don't mean to insult your intelligence but had to ask. I never see a huge difference when adjusting colors in Quickshow either.
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Have you asked LKH about it at all? I'm probably wrong about it being something inside the case as you have two projectors and both are doing the same thing. I didn't catch that originally.
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Don't despair... it happens. I think we've all had purchases that weren't as great as what we had hoped. The numbers on the powers really are out of balance as buffo stated but, it shouldn't be looking quite that magenta heavy.

[buffo]

Based on the pictures, I see lots of blue (note the blue tinge on the wall) but the fat red beam is somewhat masking everything, yielding the magenta that Brad mentioned.

So you have two problems: 1) you have too much blue and need to dial that power level back, and 2) your red beam is much larger than the other two colors, so you need to see about fixing that.

Dialing back on the blue is easy if you're using Quickshow. And from your posts above, it sounds like you already know how. Cool.

Unfortunately, #2 is a tough one to fix. A pinhole position between an identical set of lenses positioned twice their focal length apart (that is, a Keplerian Collimator with the pinhole in the middle) is the ideal option, but you might not have room in the projector for all that. You might be able to adjust the collimating lens on the output of your red module, but as Brad mentioned, 650 nm red is usually a flashlight.

One other idea might be to block off the 650 nm red beam with a piece of metal foil (inside the projector, of course) and see how things look with just the 638 red running. Of course, this means your color balance will be even further off, but if you can get a good white out of it and still get normal color otherwise, it's a start...

Adam

[kecked]

I have experienced this and the solution is drop the blue way back and the maybe red as well. You lack green. There is the pink flamingo magenta created with lots of blue and a moderate amount of red. It makes you think it's red heavy when it is really blue heavy and lacking in green. What works for me using 120mw of green is 250mw red and the same in blue. Dial in a nice yellow with just the red and green. Now add in blue to get the white you like. If you are using pangolin this is pretty easy to do in the color section. Yes you are tossing a lot of power out but decide what you want good color or bad color and bright. IF you build this yourself sub out the 120mw for a 500mw green or add a second 120mw green. This will work. The make yellow trick is how I set up all my colors. I then go back in and change the sliders over to the white one by one. Never failed me.

For the halos, maybe try a spatial filter on the resulting beam. or as he suggested block off the 650. It's wasted anyway you can barely see it. Change it out. I like 642(close to 647 kr) myself but I got use to 638 and can't tell the change anymore. 660 is even worse. and well 671.... when 532 came out I could not stand it. Now 520 looks mint and yellow is not as good.

[A1XD]

Thanks Brad

Unfortunately no the diodes cannot be adjusted. I think i will contact LKH and see if i can get them modified. Im not in the position to move to new units at the min. The positive out of this is I'm getting more work doing dance shows.

Thanks for you help so fair