fb3 qs problems dim green channel

[norty303]

Perhaps now is a good time to get feedback from Bill on whether there was any resolution to the previous investigations, as he seems to be around a bit more.

He did acknowledge that 'something' wasn't quite right previously.

[ElektroFreak]

I payed very close attention to those issues at the time. I wanted to be sure for myself that the FB3 was as trouble-free as possible before I bought one for myself..

Mine was delivered earlier this week (XE version) and I've had no trouble at all. It's an impressive piece of hardware.. Of course there could be an issue with your unit specifically badger, but I'd have to say that whatever the issues reported before were, they seem to be fixed now. I've had no trouble with output loss. My full-color system is ~700mW of white after optics using analog CNI modules for red and green, and a 445nm blue that I just put together. All lasers seem to make full power without issue.. There could be other deeper issues in play, all I can speak of is my own experience so far.

[badger1666]

@ef
i think its partly down to as doc says by design,the way software shares out power with the amount of points displayed and the lasers them selfs not liking pangolin dac i
thought all these problems were sorted now with the new software and possibly a minor dac hardware issue (showing a slight voltage drop on the g&b lines) which all adds up to
low output,but i still dont get why some cue's are ok others not and having th change the colour balance all the time depending on what cues are playing

[infredible]

Not to long ago I had a similar problem with a green Laserwave. If the displayed pattern had no blanking on the green (circle) all was fine after a half a second or two because of some thermal stability. I have since got a new generation Kvant replacement (thanks Martin) and everything is now fine.
As for your fb3 I and other on this forum had questions about the blanking signal being modulated all the time even during full on circle. I you green and blue have a tendency to Jellybeaning then the brightness becomes a lot more noticeable from on pattern to the next. I still have my Mamba2.0 and it is significantely brighter for a same given show.

Fred.

[ElektroFreak]

@ef
i think its partly down to as doc says by design,the way software shares out power with the amount of points displayed and the lasers them selfs not liking pangolin dac i
thought all these problems were sorted now with the new software and possibly a minor dac hardware issue (showing a slight voltage drop on the g&b lines) which all adds up to
low output,but i still dont get why some cue's are ok others not and having th change the colour balance all the time depending on what cues are playing

One thing I've noticed with both my DACs is that there is some dimming in certain frames due to both duty-cycle and blanking-induced power loss in DPSS lasers. I've found that if I'm doing primarily beam shows where I want the most atmospheric clout, it helps to kick the scan speed down to around 12-15k. In my experience modulating the lasers at a lower speed leads to brighter perceived output.

[Pangolin]

One thing that is missing from this discussion is the build number, and type of software you are using. That would help...

It's really difficult to troubleshoot via forum posts. Really I try to avoid this. So much "is it this, did you try that, well how about this other thing". Pictures would be better and video even better. Words just don't cut it...

One thing you should try is making sure your projector is really wired like this:
http://www.pangolin.com/resguide12.htm

We do have newer softare -- both QuickShow and LivePRO. And it's far enough along in the patent process that I don't mind giving it out now.

I am not sure if the newer software will help specifically your problem or not (because I simply do not know what your problem is from only words in a forum post) but if you contact me privately, I'll get the newer versions into your hands and you can try it. Certainly the newer versions won't be any worst than older versions in terms of "power" and we have done work in the area of "power" but only for beams. If you are having "power" problems for normal graphics or rather ordinary beam effects, then this would be more of a laser problem or it could be due to projector connections, cabling, or something else.

This is one reason why I like to meet people at PL events such as SELEM. We all get together, and see with our own eyes what is going on, and can solve the problems, often using real test equipment such as oscilloscopes and laser power meters. It's literally impossible to measure a color signal with a meter. Personally, I would never recommend it and we very often recommend against it on our own forum. And I am not quite so sure that you can see "differences" either. Sure, there might be a different voltage, but what will that really mean in the grander scheme of things? Is it due to an adjustment -- perhaps in Projector Settings being different? Different pulse width? Different what? This is where a scope comes in handy.

If you have an honest to goodness problem with the FB3, we'll certainly fix it. I just doubt this is the case, and would hate to ship things via FedEx two ways just to figure out it wasn't a problem with the FB3 after all.

Also, I do not buy -- even for just one second -- that there is something about our software that inherently delivers lower power from the laser. I've spent the last five months traveling all over the world, and I've installed QS build 128 on perhaps 120 computers and connected to 120 different laser projectors made by all kinds of people (mostly Chinese). There's often enough power coming out of the lasers to burn walls and catch cloth on fire. But it IS easy for me to believe that something's not connected right, which is one reason why I came up with the Projector Connections article... Bottom line, if the projector doesn't work right when being driven by our software, then fix the projector!

Bill

[Pangolin]

Dear Chris,

First let me say that I am sorry to hear that you are having problems.

Second, I don't often check this PL private messaging system, so in the future please contact me through direct email and that way I will receive the message soonest and will be able to reply quickly.

In any event, I think your problem has to do mostly with your lasers. If both the green and the blue are DPSS rather than "direct diode", then I think you have what I call "low frequency jelly beaning". What I normally call "Jelly beaning" is a high frequency phenomenon, where you actually see little modulated "specs" about the size of a jelly bean (hence the name). But the low frequency variant could be worst to battle. It means that if the beam is not commanded to be "on" by the software for a long enough period of time, it won't reach its full brightness. Or it could be that it does reach full brightness for a short period, but then falls down again. I would especially expect higher-frequency phenomenon in the DPSS blue laser, and -- if you've got something really crappy, for example a green laser from (company name omitted here), then I would expect low frequency modulation phenomenon in the green laser.

If you've tried other software and it does not product the problem as much, it would only be because the other software does not make as efficient use of the scanners themselves. We've worked in the field of scanning for almost as long as we have worked in the field of laser software. My college thesis was on laser scanners and we have two patents on scanners (and another two issuing this year) so we know more about scanners than virtually anyone outside of General Scanning or Cambridge. As a result of our knowledge, we have crafted software in such a way that it makes best and most efficient use of the scanners. Scanner bearings will last longer when driven by our software, and the projected image quality from our software is better. However, this development makes the assumption that the lasers are actually of good quality... which is generally the case. You have a problem, and one or two others have also reported a problem, but there are thousands of FB3 in the field with generally no problems reported.

Anyway, there might be something you can try, which is to reduce the brightness slider in QS and watch the output. If the projected image changes (for example, certain dark parts all of the sudden become bright, or the brightness variations moderate in the picture) then this is a clear case of low frequency jelly bean phenomenon in the laser. And unfortunately -- short of just getting different lasers -- there won't be anything that you, as a user, can do anything about. In fact, I have the exact same problem in the green laser of my projector. The only answer is for me to change out that green laser, but I haven't had a chance to do that yet.

By the way, while at the PALM show in Beijing, LaserWave showed an integrated RGB laser and they made a projector out of it. The projected images were very nice -- no sign of any modulation effects what so ever.

Bill

[Doc]

Badger, I improved my green performance considerably by re tuning the diode and crystal TECs under modulation rather than CW.

I had previously temp tuned my green for maximum power (circa 1150mW), but I had done this with 5v on the mod line.

It struck me that maybe I could improve things by tuning the temps whilst displaying a frame with the FB3; I just projected a green circle at the maximum power available and was suprised to read 180mW!

I then set about tweaking the TECs in the usual manner and things settled down around 400mW.

Now I get 1050mW from the green in a full power beam, well 5 beams on top of each other (previously around 700mW).

The green is now far punchier and less noisy whilst projecting shows, after warming up for 5 minutes.

Edit: I have also istalled the new LivePro which didn't seem to make much difference to power levels.