My green is doing strange things

[White-Light]

OK the thread has come full circle after some tests and I think we can now see the wood for the trees.

I think there were 2 separate issues affecting different users, which probably clouded the picture slightly.

I think Chris is probably right that Phredy's problems is his TEC and by turning the power down he's reduced the heat and increased the stability of his lasers thus solving his problems. Good call Chris.

For the rest of us, myself included, I think the problem is modulation with the DPSS green unable to keep up with the modulation frequency demanded by some of the cues. I don't think this is a Pangolin problem but one probably to be seen across the board with all software containing certain types of cues.

I'll add a video clip later, but what I found was that with the Animals > Orca cue correctly displaying white and blue the frog cue, was white not green. As my projector has an excess of blue, I turned the blue down on the projector itslef until the frog just became proper green. A return to the Orca cue then showed the Orca to be blue with green tinted white highlights, not I think due to an excess of green as I didn't turn the blue down that far, but due to modulation. This then appears to be confirmed using Sheets > Cue 05 which is two all white sheets with gradients to black at each end and a gradient to black in the centre. This shows white centres but green ends on sheets - typical of modulation issues.

Video to follow so other users can verify this against what they're seeing.

[badger1666]

yeah al its defo not the software.
here's a test i did a long time ago to confirm this, scan a green cone in beyond or qs , look down it to see said effect of bright and dark bands in the cone that move about(in white its shows as pink bands)
if you adjust the brightness while looking down the cone you can watch these bands jump around alll over the place.
next step i did was hit a switch on my laserwave driver that puts it in to cw(this removes sofware from modulating the green) and behold the problem was still there
not quite as bad but still there

[White-Light]

Had to abandon the video. The luminosity was so bright you couldn't see the colours I was talking about.

[swamidog]

take the iso on your camera down to around 100, goose the fstop to 20 or more, and set your shutter speed to 1/30th of a second.

Had to abandon the video. The luminosity was so bright you couldn't see the colours I was talking about.

[Phredy1]

I'm first going to test the same projector on LD2000 and Beyond and compare to what's happening in Quickshow. I highly doubt it is anything software or DAC's - QM2000 Pro vrs FB3, but that is going to tell me something. If it's the same on both, and I suspect it will be, then it's the green. I'm siding on TEC issues, but it could just be it's a Laserwave....

I have everything setup for a show Saturday night, so sometime next week I'll do more testing.

[White-Light]

I'm first going to test the same projector on LD2000 and Beyond and compare to what's happening in Quickshow. I highly doubt it is anything software or DAC's - QM2000 Pro vrs FB3, but that is going to tell me something. If it's the same on both, and I suspect it will be, then it's the green. I'm siding on TEC issues, but it could just be it's a Laserwave....

I have everything setup for a show Saturday night, so sometime next week I'll do more testing.

Yeah it's always good to test. However, when I tested yesterday I ran both QS and Beyond back to back, and could see no difference in the results.

I have to say irrespective of the possible tec side of things, it's well worth getting a Stanwax / DZ colour correction board in your projector. The difference in colours in Jem's last projector before and after was staggering. Colour correction is high on my list of things to get done.

take the iso on your camera down to around 100, goose the fstop to 20 or more, and set your shutter speed to 1/30th of a second.

I'm using a high level consumer video camera. Unfortunately as good as it is, it doesn't have full manual control so the best I can use for bright events is "Spotlight Mode". Although it coped with part of the video OK, the other part over-saturated one of the test cues to white and no matter how I tried to rebalance it in the editing software, it was so burned in that any other colour wasn't recoverable.

Dangers of shooting 2w+ laser from 3-4 feet from the wall.

[Pangolin]

For sure, DPSS lasers can be problematic. I coined the phrase "jelly beaning" years ago, when DPSS first came onto the market and modulation was attempted. This phrase is meant to describe the visual appearance of a line projected by the laser -- it looks like a bunch of jelly beans lined up, end-to-end.

There is also a lower-frequency variant of this, which may have to do with thermal effects inside the laser. And finally, in an attempt to protect the laser diode, some manufacturers place capacitors directly across the laser diode -- these capacitors generally being unreasonably large -- for example 1 uF.

A few years ago, to try to be part of the solution (always trying to find solutions instead of just simply complaining about the problem), I've been consulting with laser diode manufacturers and driver manufacturers to teach them how to modulate faster, modulate consistently, and avoid modulation problems. LASORB also plays a role in this, because driver manufacturers can rest assured that they no longer need *ANY* capacitor to be placed across the laser diode for protection.

Regarding green lasers -- after I modified the driver of my DHOM laser (also known as Ultralasers), I've been very happy with it. Jelly Beaning does exist, but only at very very low light output levels which occur rarely in real images. I've also been very impressed by the Laser Wave lasers that I have seen and that we use at tradeshows. I can't speak for all models manufactured on all dates, but I can speak for the ones we use at tradeshows and the quality seemed great.

Bill