Feeble output from FB3

[norty303]

Ok, but again, what are those laser powers in each one?

I'm becoming more and more convinced we might be comparing apples and oranges here.

Oh, and if you can give some detail in your Pink Floyd picture thread, might be able to tell you if what is being seen is about right for the projector (as much as can be done with a photo)

[smokeAndMirrors]

Ok, but again, what are those laser powers in each one?

I'm becoming more and more convinced we might be comparing apples and oranges here.

Oh, and if you can give some detail in your Pink Floyd picture thread, might be able to tell you if what is being seen is about right for the projector (as much as can be done with a photo)

Yeah I posted the details in that thread.

[smokeAndMirrors]

Update: the green channel in the laser/FB3 is behaving badly. At switch-on it's nice and bright; within a few minutes it's dimmed to some very low power. Can't find my flippin' Laserbee at the moment so can't take measurements, but I watched the green visibly fade before my eyes.

Also the DMX controller board seems to have died, as its screen has gone blank. Whether these are in any way related, I can't say - probably not though. And of course theoretically it could be the FB3 that has a naffed-up green channel (I had issues on one of my other projectors previously with the green - if it wasn't sitting waiting for a new set of scanners I could test to see where the problem lay, doh).

Anyway whatever the cause, I'm pretty sure the fading green is to blame for the lack of perceived power.

[polishedball]

Update: the green channel in the laser/FB3 is behaving badly. At switch-on it's nice and bright; within a few minutes it's dimmed to some very low power. Can't find my flippin' Laserbee at the moment so can't take measurements, but I watched the green visibly fade before my eyes.

Also the DMX controller board seems to have died, as its screen has gone blank. Whether these are in any way related, I can't say - probably not though. And of course theoretically it could be the FB3 that has a naffed-up green channel (I had issues on one of my other projectors previously with the green - if it wasn't sitting waiting for a new set of scanners I could test to see where the problem lay, doh).

Anyway whatever the cause, I'm pretty sure the fading green is to blame for the lack of perceived power.

Have you swapped the red or blue modulation lines in place of the green line? IE drive the green laser with blue's modulation. I'd guess you have a dying green laser more so than a failing FB3. This could help to prove one or the other.

[norty303]

OR you could simply project a white circle and measure the channels with a volt meter. Although it won't show the true peaks, it will show you if one is averaging lower than the other. So if blue and red are at 3.5v and green is 2.5v, you know where the problem is.

I'd suggest it may be heat related if its fading over time after warmup.

[Doc]

I'd suggest it may be heat related if its fading over time after warmup.

^^^ +1, sounds like a failed or poorly adjusted TEC to me ^^^

[norty303]

I'd just like to update here, as my recent experiences may prove of value.

I had a Laserwave green go low power on me, so it got returned to Rob, and resulted in a warranty exchange.

The one returned to me settled down to just over 300mW CW (it was rated at 300mW) which I found a little dissappointing. I contacted Rob and he advised I try it on the FB3 and see how it performed under modulation.

So I ran tests over half an hour each using the LaserMedia test pattern, a single targetted beam, and a static circle.

In all tests the laser gave a steady output of at least 430mW after initial warmup.

This proves a couple of things to me:

1. Pangolin have clearly addressed the issue of low power beams in their software
2. Any issues that scanned images may be down on power unless doubled or trebled seem to be unfounded
3. The modulation efficiency of the laser seems to be a significant factor in the power outputs
4. CW power ratings are not representative of real world conditions for display use - perhaps we should be demanding different specs of the manufacturers. I know Laserwave are tuning for modulated outputs these days.

[Pangolin]

I'd just like to update here, as my recent experiences may prove of value.

Yes, very much value, especially coming from someone as experienced as you are.

1. Pangolin have clearly addressed the issue of low power beams in their software

I am glad you have come to that conclusion Norty! I know there were posts in the past where you were skeptical...

2. Any issues that scanned images may be down on power unless doubled or trebled seem to be unfounded

I am happy to hear that they are "unfounded" in your case. However, certainly lasers made by each separate manufacturer -- and even lasers made by the same manufacturer but of a different design -- may give different results when modulated. The most recent lasers coming from LaserWave do look quite good in terms of their modulation response. That's something I have noticed at the last two tradeshows where we saw them. The output was very linear and consistent.

3. The modulation efficiency of the laser seems to be a significant factor in the power outputs

Yes, of course

4. CW power ratings are not representative of real world conditions for display use - perhaps we should be demanding different specs of the manufacturers. I know Laserwave are tuning for modulated outputs these days.

It would be a good idea for manufacturers to show input and output waveforms. This would help in the buying decision. (Perhaps that's not why it is done now .)

Best regards,

William Benner

[norty303]

I know there were posts in the past where you were skeptical...

I was never skeptical about the targetted beams Bill, I think thats why I became frustrated in our past comms, as it was the scanned pattern performance I was querying, but the responses always seemed to be about the beams... always the beams....

Anyways, glad you liked the post