Pangolin Beyond Info Thread

[Pangolin]

I was in a similar situation. We have computers all over the place. Kind of a club med for geeks. Some of the teenagers wanted to write/create shows to be loaded on to the laser controlling computer and I thought why not let them work on the software? The idea was to generate some interesting shows by letting several people create in parallel. The shut downs were a hassle ( I thought it was a beta version glitch) and we just dropped the idea. Maybe I should contact P and see if they are OK with freeing us from this restriction.

We have a way of letting most of our software run on a specific PC forever and without hardware. This is in fact what we did, as an interim solution, for AndyH. So this can be done for you. However, I was not aware of this specific problem until just now, after re-reading posts in this forum.

Planters, I didn't notice that this is what you wanted to do until just now -- after re-reading the forum posts. Please know that you can contact me by email at any time and I will have had a solution in your hands in the next email! That's why we always prefer it when clients contact us directly and as soon as a problem is seen. That way we can get it fixed and turned around (or get the question answered).

[Pangolin]

Good afternoon laserists!

We have new software in the works that lets you control color in a different way, and also a lot of development in the area of DMX. If you are using projectors with more than three lasers (i.e. RYGB or RGCB or RGBV) -- or if you are using three lasers but have a difficult to tame color balance (heavy green or heavy blue) please contact me and I'll make arrangements to get this new software into your hands. In-house results look very promising but we'd love to hear how it works for you. Likewise if you're controlling moving light fixtures or have other complex DMX needs, please get in touch with me.

Also one more point along these lines. If you watch our Digital Cafe video here ( http://vimeo.com/39632592 ) one of the things that you'll learn is that I love to hear from people. I love to hear how you're using the program, what kind of shows you're doing with it, if you're struggling with anything, etc. It really does influence our development efforts.

When we learn of great laser shows or even innovative applications, we help to promote these in magazines like Mondo and TPI. When we learn that there are struggles, we take this into consideration. Sometimes we can't solve a problem immediately, but we always do keep it in mind for developments on down the road. Indeed QuickShow came out of out observation of the struggles people had to get certain tasks done quickly. And the latest debate started by Andy H has actually sparked interest in a way not only to solve this problem (immediately, with a special license file sent to him, and over the longer term with changes made in the program), but also a new way to sell the program too. Great stuff guys!

Best regards,

William Benner

[Things]

Good stuff Bill

Curious, I don't have any kind of colour correction board in my projector, though it seems to me as if it'd be something that could be corrected in software. Is there any plans to add sort of an individual colour shift feature to BEYOND?

Regards,
Dan

[planters]

I agree with Things. It seams that a timing offset, within the software, to compensate for each color's different modulation performance, might be useful. In addition, I am working on a projector that will mix galvo blanking with several diode based lasers and it would be nice to coordinate TTL control without giving up the advantages of analog control where possible.

[Pangolin]

Hi Things and Planters,

You bring up a great and important point. Here are our thoughts. They might sound strange at first, but I hope you can get into our mindset.

First let me say that -- whenever possible -- we'd rather be part of the solution rather than part of the problem.

In the case presented above, the problem is that some laser diode driver manufacturers incorrectly try to protect their lasers from ESD by piling on all kinds of capacitance right at the laser diode itself. This really slows down modulation capability. Since there is a lot of "monkey see, monkey do" in this business, each next laser diode driver manufacturer does largely the same thing, but perhaps in a slightly different way. At the end of the day you have a variety of manufacturers with a variety of delays -- none of which actually need the delay or even know why they are doing this.

If we wanted to simply propagate the problem, we might do as you say -- try to overcome the delay externally and artificially. But to do so would not really solve the problem. It *might* hide the problem in some cases, but not all cases. And regardless of the delay, the modulation is slowed down, so it prevents the laser from doing raster images and special kinds of abstracts. So adding individual software delays is -- at best, and incomplete solution.

So rather than propagating the problem, we'd rather work towards a solution. Specifically this solution comes in a single form, but two steps. First, we educate laser diode driver manufacturers on how to make their drivers better. Second -- if they feel that they need ESD protection, we offer LASORB. Unlike a huge capacitor, LASORB does not slow down the modulation and in fact, will allow modulation rates of 125MHz or higher.

Let me talk about a parallel situation that existed with laser projectors just a few years ago. When Justin and I toured China and went to many laser projector manufacturers, we brought along a copy of QuickShow. What we found was that some projector manufacturers had outputs that were upside-down, or rotated, or sideways. Some had red laser connected to the green output, etc. Some laser projectors had unstable images caused by ground loops. It was a real mess. So what did we choose to do? We created an article on Projector Connections -- effectively teaching people how to build a laser projector. Then we had this article translated into Chinese and Japanese. Then we physically went to every single projector manufacturer, brought them a copy of the article, and explained it to them. The result? A year later almost all of the projector manufacturers are making really good projectors. Last year we did not notice a single projector whose images were the wrong orientation, and at Prolight & Sound, the Chinese company whose booth was across from us was making projectors nearly as good as Kvant.

If we wanted to simply propagate the problem, we'd have put switches and such inside our software to rotate, invert, change colors, etc. (In fact we did this too.) But rather -- a better solution for the entire world at large (not only Pangolin clients) was to teach projector manufacturers how to do a better job.

Currently we are working with laser diode driver manufacturers all around the world to help them to understand the problems and how to solve them. This is a better solution for everyone -- not only Pangolin clients -- because it means all lasers would actually work correctly, rather than having a problem that is simply masked. So regardless of whose software you use, you will get good results. Plus, the lasers will be able to reproduce all kinds of imagery, including rasters and special abstracts with high frequency color modulation.

As was the case with our quest to educate laser projector manufacturers, our quest with laser diode driver manufacturers is having tangible and positive results. We see fewer and fewer lasers with a delay. Generally better results. However, if there is a laser diode driver manufacturer whom any of you see as still problematic, let me know and also let me know their contact information. We'll get in touch with them and offer our advice. We do this AT NO COST TO ANYONE -- simply because we want all of the equipment in this industry to work well together.

I agree with Things. It seams that a timing offset, within the software, to compensate for each color's different modulation performance, might be useful. In addition, I am working on a projector that will mix galvo blanking with several diode based lasers and it would be nice to coordinate TTL control without giving up the advantages of analog control where possible.

If you're good with circuits, get with me and I'll send you a circuit diagram that will help to synchronize all of your modulation sources. If you're not good with circuits, I think Rob Stanley might have taken up a circuit I originally helped DZ to put out.




Best regards,

William Benner

[Things]

Thanks for the reply Bill, I do see what you're saying

My main issue is the green really, and DPSS's poor modulation response. I always seem to end up with green tails on everything, just thought it could be nice to correct that in software.

Dan

[taggalucci]

Thanks for the reply Bill, I do see what you're saying

Agreed, and I've read Bill's opinion on this previously somewhere here on PL.

...just thought it could be nice to correct that in software.

Agreed. All of what Bill has said makes sense... however it would still be good to have a soft-option for those that want it. Not because its the "right" thing to do, just because it is something a number of us Pangolin users would appreciate having as an option i.e. a per-interface, individual colour channel, linearity and offset correction control.

How about a meter-connected or meter-reading-entered utility allowing the linearity to be trained based on the measured laser output per channel?

[absolom7691]

My main issue is the green really, and DPSS's poor modulation response. I always seem to end up with green tails on everything, just thought it could be nice to correct that in software.

If you have green tails then the laser manufacturer is clearly using the same capacitor-based protection that Bill was talking about to keep the pump diode safe. While I don't have this problem, my green problems are temperature based. With my green all nice and warmed up, I get beautiful performance and ultra fast modulation. When it is cold, the modulation is still fast, but the brightness is terrible. If a show doesn't call for green for 15+ seconds and the green laser cools down, the next time the green is needed, my white-balance goes to hell. I guess what I was trying to get at is that what Bill suggests might be a better solution, in the long run. Although it will take time to get to every A, B and C manufacturer in China. Otherwise, if you start making these fine tune changes, you will find that you are hitting a moving target since greens are tmpermental like this. I would think the only hope for DPSS greens is to stick a monochromatic AO mod in front of it. I am thinking of doing this with my green. Hopefully a single ch AO mod is not too expensive.

[Pangolin]

Hi guys,

Just a few more thoughts.

Sometimes, while talking about this, I'll try to create an analogy with X-Y scanners. OK guys, we have X-Y scanners, and both scanners have to be going the same speed right? It would be absolutely unacceptable if one scanner went at half the speed of the other scanner right?

Now, if you had such a situation, is it possible to build a pre-filter to effectively slow down the fast scanner? Sure, that would be possible, and the result is exactly the same as using my pre-filter circuit, originally noted on this page ( http://www.pangolin.com/resguide03d.htm ) and for which I've worked with DZ to produce a product to do this, and for which I believe Rob Stanley now sells a similar product. So sure, that's possible. But is it acceptable? To me, this is no more acceptable than having one scanner that runs at half the speed of another scanner.

I'd like to try to be part of the solution here guys. Let me know how I can help you -- insomuch as fixing the problem with the green lasers. If you want to send your green lasers to us, we'll put them on the bench and modify the driver so it is faster. (I had to do this with my DHOM/Ultralasers driver too.) If there are particular laser diode driver manufacturers that are still producing slow systems, let me know and let me know their contact information and we'll try to educate them to help improve their products.

Best regards,

William Benner

[absolom7691]

I am using Viasho, from which I hear, make decent lasers. It seems like most of the problems that affect these lasers, both green and blue, is caused from temperature instability internally. I would imagine better temp control for the YVO4/LBO and KTP would lead to more stable power and also modulation as well. Pushing manufacturers for that would be nice!