are video projectors replacing laser projectors for graphics?

[flecom]

What I want to know is how much wood could a wood chuck chuck if a wood chuck could chuck wood?

[TechJunkie]

Is that all? Not bad considering that a good portion of the members here use Pangolin. Sig spam? Okay, I'll fix it.

You dont have to change your sig, I was just making a point.

I do agree that a good portion of members use it. But there are also a good amount of members who follow Bill around like puppies waiting for a treat. They also plug the Pangolin name everywhere they can. I'm not built that way. I fly my own flag, always have. I have nothing against Bill, or Pangolin. I just think the spam needs to be thinned out a bit. I also think people need to focus more on the art, and mechanics more than companies. You can say what you want about LPF, but at least there was more innovation, and information than shop talk. This forum can be quite intimidating for the n00b. Without new blood any forum will become stagnant, and redundant.

[TechJunkie]

What I want to know is how much wood could a wood chuck chuck if a wood chuck could chuck wood?

None. Wood chucks dont chuck wood even if they could.

[White-Light]

No wonder some people here think video projector emulating laser graphics will look shit. You'll need more than a lousy 600x600 frame, you'll need more res, antialiasing and filters to emulate the look and feel and look good.

The probable reason why the resolution is low is to keep the brightness up.

With a laser the beam is always bright because it's always got the same characteristic eg if you have a 3x3 beam with 1.2mrad divergence, you have that even when you have a fan. The brightness is not spread over the fan but what you have is a 3x3 beam moving back and fourth giving the impression of a fan due to the eye's persistence when in fact what you still have is a 3x3 beam with all the associated density and brightness.

With a video projector you have the opposite. As I understand it, you have a full screen projection where the brightness is spread over the whole area and all the pixels are active and emitting light (emitting in LED, reflecting in DLP). As you reduce the size of the projection area, you do so by effectively switching off pixels. This means that as the projection gets smaller so the brightness reduces in proportion.

That is why simulated laser via a video projector works quite well with fans, sheets, boxes etc, but not so well with narrow effects such as tight single beams, which appear dim by comparison.

My best guess therefore would be that the reason why Pangolin use a low resolution is to keep the brightness as high as possible.

..and that in a nutshell is why a video projector won't look as bright as a laser when drawing lines = the laser is at full brightness, the projector is only at a fraction of it's possible brightness.

The there's coherence and the fact that the laser doesn't lose as many photons on it's way to the projection surface.

I think Eric already explained that above, but in a much more technical and scientific way. So there's the simple version.

[absolom7691]

You dont have to change your sig, I was just making a point.

I know but I was trolling. Playful banter is fun, no?

I do agree that a good portion of members use it. But there are also a good amount of members who follow Bill around like puppies waiting for a treat. They also plug the Pangolin name everywhere they can.

Why do you think that is? I mean, in all seriousness, there is a reason. It's not just blind fanboyism. I already told you the list of softwares and hardware I own. It comes down to what I am willing to settle for. For some, "good enough" is good enough and there is nothing wrong with that. I am not that way. I want the best I can afford. Pangolin happens to fit that bill. If it were another software, I would spam that one. When people ask for advice, I am going to give the benefit of my experience e.g. "I have used all of these others and spend X amount of money. Of them, 'this one' is the best." Especially when I can pretty much tell that they will buy cheap and then buy more expensive later and curse themselves for having to buy things twice. I have done it before as have MANY. I would say 90% of the people bitten by the bug go that route.

About following Bill around, there is also a reason there too. It also isn't blind fanboyism. Bill has done a hell of a lot for me and one of the best ways I can show my gratitude is by, not just blanket advertising his company, but giving my honest testimonial about the products I use (when asked). I have also stated, openly on this forum, stuff about the software I don't like. So again, not just blind fanboyism where everything is 105% perfect 105% of the time. Bill is also an EXTREMELY smart guy. Talk about innovation, this guy have been innovating for a couple of decades now. If I can't innovate, then I hitch up to the best innovator in the bunch.

I'm not built that way. I fly my own flag, always have. I have nothing against Bill, or Pangolin. I just think the spam needs to be thinned out a bit. I also think people need to focus more on the art, and mechanics more than companies. You can say what you want about LPF, but at least there was more innovation, and information than shop talk. This forum can be quite intimidating for the n00b. Without new blood any forum will become stagnant, and redundant.

Flying your own flag is cool too. I do my own bit of that on the hardware side. I don't like pre-fabbed projectors because I didn't build them. There is art in the fabrication too. No two homebrewed projectors are the same and some are down-right esoteric pieces of fantastic art *See planters' projectors.

My only beef with LPF is the safety of pointers. I know most of those guys are responsible about their pointers and try to stay safe. My beef is when someone can stumble onto the forum and locate parts and construction notes and have no idea about the dangers involved. I don't believe in censorship but I also don't believe in glorifying devices that are high powered, CW beams in teh hands of someone who shouldn't use them. I am sure the forum is great and is full of great people.

For a noob with lasers, it's always daunting. There is still so much I don't know and I always feel intimidated. When Steve Roberts always has the exact perfect information for almost every laser in existence, I go into Wayne's World mode: "We're not worthy!!!!"

[planters]

I don't want to persist on the solely technical, but white-light has it right. A HD video projector that generates a single pixel spot at the screen is dumping 99.99995% of its output. Unlike a galvo that moves all the photons to a particular spot a DLP micro mirror is committed to illuminating a particular spot; it can be commanded to only two positions ie ON or DUMP. A couple of years ago, I thought (with cleverness born of naivety) that each mirror could act as an individual micro galvo steering its beam around and potentially producing an amazing 2 million mirror, super parallel projector. I communicated with TI about their development kit that would allow me to begin applying this to lasers. The problem I learned is that the only way a 3-4um mirror can produce a far field spot equivalent to 0.7mrad is that the large diameter projection lens is actually re-imagining the pixel (dark or light). A collimated beam 3-4 um in diameter cannot have this kind of divergence (outside of the X-ray regime). It is forbidden by diffraction effects. Hence, the light from a bright pixel is captured by the full diameter of the projection lens aperture and refocused on the distant projection screen. This makes the already comparatively low power of a single pixel hundreds of times dimmer close to the projector and so dim it is undetectable [10^(-9) vs a laser]. Even if you could adjust the mirror angle gradually (the system does not allow this, but it's theoretically possible) the spot would only grow dimmer, it would not move.

My practical, hands on experience with a very bright (Acer) video projector is that with the multi-pixel line widths that the image on the screen approached a 1W RGB laser in appearance. The higher bandwidth does in fact help a lot to even the score with more complex graphics.

[flecom]

stop trying to use logical arguments... just quickly dump all your laser shite before the DLP projectors take over!!! run for the hills!!! the sky is falling!!!

also the neat thing is all those DLPs can be killed by one 445 pointer!

[absolom7691]

Not to mention the mutlicolored rainbow effect when shifting view. I don't know how people can stand that. Talk about triggering epileptic seizures. If I ever bought a projector, it sure as hell wouldn't be DLP. I would buy LCD only.

[White-Light]

Thanks. I think you just didnt get my reply, sorry. Point was, unless youre comparing a single laser point projection, brightness of lasers also decreases as galvo speed increases. That's the reason why some run beam shows at 24K or less even on 30K or 60K scanners. It appears brighter. Anyone owning a laser can try this. The fact that you said you personally had a bright projector approaching a 1W laser projector in appearance while "each pixel is 99.99995% of its output" kind of shows it.
BTW, can you remember which model the video projector was?

flecom: you fail at trolling, that was already said.

Technically that's not correct, the brightness of the laser never changes. What changes when you scan faster is the laser beam spends less time in one position (dwell) so the laser appears dimmer. Even then, it's not a huge change in brightness. I can hardly see any difference with graphics between 30K and 20K, if at all. In fact in all honesty, I'd say I don't notice any difference 99% of the time.

With a video projector, project a small spot and 99% of the output is off, so you have only 1% of the maximum brightness. That's why laser trumps video for narrow line projection brightness.

At the end of the day, laser is best for beams and outline graphics such as logos or simple animation. Video is best for films. Simples.

[m0f]

Video projectors have been in use for years in live entertainment. LED walls are gaining popularity over them lately due to the massive contrast and brightness. No need to wait for it to take off, it very much so already has, and there is no shortage of software and plugins to make use of them for those purposes.

That being said, they are a completely different medium from lasers. Most shows for lasers are beam shows, however graphics shows still have their place. Lasers are perfect for outline and simple text or logos type long range projections, high brightness projections, projections onto surfaces of varying distances (video projectors need to be focused to one distance) and projection onto surfaces of darker colours. And it just has a different look to it. There will always be particular uses where laser projectors excel at and at the same time uses where video projectors excel at.

Don't think of it as a competition. If fact, 99% of all of the gigs I've been involved with use combination of both, and they can work beautifully together. LED walls however are a pain due to the intensity, as it's easy to wash out beam effects completely, but just takes good communication and cooperation between operators to make for the best of both worlds.