Aligning The Laser Beam - A Nub's Question

[Doc]

yeah.. I have a tendency to overlook ishow DACs completely. They are worthless..

I have to disagree with you there, the one on my desk does make a really effective coaster, they also work well to deter one's cat from scratching the sofa (when aimed right)

[XysteR]

I have to disagree with you there, the one on my desk does make a really effective coaster, they also work well to deter one's cat from scratching the sofa (when aimed right)

LMAO! Now i like that idea!

[ElektroFreak]

LOL awesome Doc!

XysteR: You're basing your responses on very limited experience. Granted your experience has been with very good hardware and software, but there are MANY other possible options for a DAC besides the FB3, most of which are very good. There are many other choices of software, also most of which are very good. Pangolin rules, but they're not the only valid option. If the only good combination of hardware and software is an FB3 with an analog laser, many people's PERFECTLY AWESOME laser projectors don't fit the bill. There's no reason to limit the entire laser projector world to a handful of components when there are many different perfectly valid options. That's half the beauty of it, to me. Not to mention that in the case of the FB3 vs. other DACs, a little competition is a good thing.

[XysteR]

LOL awesome Doc!

XysteR: You're basing your responses on very limited experience. Granted your experience has been with very good hardware, but there are MANY other possible options for a DAC besides the FB3, most of which are very good. There are many other choices of software, also many of which are very good. Pangolin rules, but they're not the only valid option.

Entirely, i exhausted myself deciding, spent weeks reading forum after forum, as you well know i was toying with the idea of making a soundcard DAC, ultimately and after having a hell of a lot of people highly recommending i buy the FB3 i went with that. Its expensive yes, but i'm 100% over the moon with its performance, even more so now with QuickShow its just an incredible package! I don't just love the FB3, i love everything else that comes with it. The great service from Pangolin and free updates. I paid nothing for QuickShow and its one hell of a step up from LiveQuick. I could tell QuickShow was impressive when i was beta testing it. I only just downloaded it last night and had it running my projector shortly after and its unreal! So much more flexibility and power for no outlay! He's decided on the FB3, all i can do is confirm how awesome it is and that he'll not be miffed with his perchase.

[ElektroFreak]

You are right. The FB3 is awesome because it allows you to use Pangolin's software which IMO is where their real prowess lies. I've been planning to buy an FB3 for that very reason, but I'm waiting for a resolution to some issues that a few folks have had with theirs before I buy. Quickshow is the deciding factor for me. It looks incredible. And the FB3 is actually comparatively cheap compared to many other options.

[XysteR]

You are right. The FB3 is awesome because it allows you to use Pangolin's software which IMO is where their real prowess lies. I've been planning to buy an FB3 for that very reason, but I'm waiting for a resolution to some issues that a few folks have had with theirs before I buy. Quickshow is the deciding factor for me. It looks incredible. And the FB3 is actually comparatively cheap compared to many other options.

I can't say i've had a single problem with the FB3. One important thing i will say about QuickShow is how much quieter my scanners are now. I don't even hear anything from them, obviously Quickshow aint just a much better piece of software than LiveQuick on a GUI level, its a hell of a lot smarter at controlling your galvos. The bonus of this is that if its not hammering your galvos to output complex stuff then by using QuickShow your prolonging your galvos lifespan. If you aint already, check out the QuickShow PDF file on Pangolin webby.. Right, i'm off for fish & chips! :P

[buffo]

Why on earth does the DAC matter? ANY DAC will provide analog outputs, regardless of what brand or model it is.. even a homemade DAC will do this.

Oh wow. You might want to retract that statement...

There are *lots* of controllers on the market that only support TTL color. In fact, one of the most popular live controllers (behind Pangolin) is the Full-Auto and older X-29 series, and BOTH of them are TTL-only. Yet both DreamBeamz and Gottaluvlasers (among many others) still use these systems to this very day to perform commercial live laser shows set to bands and DJ's.

My first controller (Alphalite XC Pro) was a TTL-only controller. Norms Laser Show controller is also TTL-only. And the Poplescan LPT DAC is TTL only. This is just off the top of my head - I'm sure there are many more that I'm forgetting.

Analog controllers used to be a curiosity, unless you were talking about the high end units. It's only been recently (in the last 5 years or so) that truly affordable analog controllers have been available at all. But there are plenty of TTL controllers still out there.

An inexpensive 100mW TTL laser is an excellent starting point.

Indeed. My first projector had a 100 mw TTL DPSS green laser in it. And I must admit, I had a lot of fun with it. But like most cheap DPSS designs, it suffered from all sorts of power instabilities, especially when modulated. PWM for power control was absolutely not an option for this laser. Even modulating it at normal scanning speeds caused significant power loss. An analog driver would have helped a good bit, had I known to ask for it back then. (I later purchased another one of these same lasers and had it modified for analog modulation, and it performed quite well, so I'm speaking directly from my personal experience here.)

These days, adding analog control to a DPSS green isn't that expensive. The benefits far outweigh any small increase in price.

yeah.. I have a tendency to overlook ishow DACs completely. They are worthless..

I agree that they aren't very good, but that label applies to a lot of controllers on the market, not just Ishow.

In the real world, however, DPSS lasers (green and most blue) do not respond to analog modulation in a linear fashion.

They are not always strictly linear, but between software correction and DZ's color correction board, you can get very good performance out of even substandard lasers. Case in point: my current RGB projector. I've got some seriously shitty lasers in there (Lasever units , built before they fixed the cavity design), and they have lousy modulation response.

Nevertheless, I can get incredible color blends with my projector. Why? Well, for one, I spend a lot of time setting up my palette with the color wizard that comes with Pangolin. Also, DZ and I spent an entire weekend adjusting and re-adjusting my color board to get it just right. (That's where the adjustment tutorial came from. We figured if we could tune the board well enough to compensate for my shitty lasers, it would work just as well or better for anyone else's projector.)

ALL DPSS lasers respond somewhat similarly to analog modulaton.

Some brands are markedly better than others. Trust me, you don't know shitty until you've seen my lasers! But I've also seen the output from several projectors with all LaserWave units, and I have to say, I'm quite impressed. In one case, the output of a bare projector was just as good as my projector with a perfectly adjusted color board and a hand-tweaked Pangolin color palette. That's saying something for the quality of LaserWave.

you will never see anywhere near the maxmum color palette when using DPSS lasers. You might get a few hundred colors in the best cases.

You may not get 16.7 million colors, but that's irrelevant since the human eye can't distinguish that many anyway. You can *certainly* get more than "a few hundred" though. You need to watch the "Gradient-Moby" beamshow that comes with the LD-2000 system from Pangolin. It will change your mind forever on how many colors are possible from an all-solid-state RGB projector.

You're basing your responses on very limited experience.

I think you are guilty of this as well. I urge you to attend a LEM in the near future and see with your own eyes what I'm talking about here. Because you *can* get great color performance out of DPSS lasers, with the right combination of hardware and software. It's not easy, and it's definitely not easy if you have lousy lasers to start with, but it can be done nonetheless.

And finally, yes, a PCAOM is, without a doubt, the best color modulation you can get. But it's also very expensive and very lossy, which frequently prevents it's use in a hobbyist's projector. Nevertheless, I've got two of them sitting on the shelf at the moment, waiting to be installed in an ion-laser-based projector that I really need to get around to building one of these days.

Adam

[ElektroFreak]

I'm not retracting anything, however I was already corrected about this previously in this thread, which I will acknowledge. I don't know much about older DACs, but from what I do know, the majority of current-production DACs provide analog capability as a basic function.

While I might have underquoted the number of colors possible with DPSS, you get my point..

It would seem that I need to get my hands on a color correction board.. I'd love to see what that could do for my RGB..

You would know better than I about these things, no doubt. We all have some sort of limits to our experience, though, so I am most certainly guilty of basing my responses on my own limited experience.