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FrozenGate by Avery

Question about Galvo Speed?

If you have eye-strain, the solution is to adjust that on your end, not subject everyone to unreadable ALL CAPS text that shouldn't even be posted no matter what the content or relevance. There is no excuse nowadays to use all-caps in body text. No excuse ever.

All modern browsers allow you to adjust the fonts/zoom on your browser to your liking. Hold Ctrl and scroll your mouse wheel, or hit Ctrl - +/- to adjust the font sizes on your browser. Ctrl-0 resets those fonts. You can also use your View menu on your browser or whatever equivalent.

I tried that, but the grey background used on LPF was breaking up and mangling text when I scroll with the larger fonts, its a display driver/Win7 issue on Acer Laptops, and its annoying. I tried both Explorer and IE, and had the same issue.

I'm on a different browser now, with a new driver, and can see.

Again, I'm sorry for any issues, but some times you do what you can do with with what you have. I'll see if I can find a utility that strips the single bit in the ASCII.

Steve
 





Steve, 99% of my bad experiences have come from other people in the laser community not you. I have only criticized your sense of entitlement, not you or your contributions. We do not agree all the time, but that is not required. I've tried to make sure that the harshest of my criticisms have not been aimed at you directly, there are plenty of other faces in the pro community and I haven't called anyone out by name. You may disagree with me and my opinions, and that's fine, but I do consider you to be one of the worthwhile members of the pro community, and I've told you that before. Nothing has changed.
 
I tried that, but the grey background used on LPF was breaking up and mangling text when I scroll with the larger fonts, its a display driver/Win7 issue on Acer Laptops, and its annoying. I tried both Explorer and IE, and had the same issue.

Sometimes the hardware acceleration will revert to the old anti-aliasing methods that look terrible. I had to disable hardware acceleration in IE (when I was testing it) to get back my cleartype rendering the way I liked it. IE used to also do some combination of scaling and zooming, which didn't quite work perfectly.

Also try calibrating your fonts in the display options (right-click desktop -> Screen Resolution -> "Make text and other items larger or smaller"). Having medium or large fonts helps the eyes a lot, especially on high-DPI laptop screens.

(I realize this is terribly off topic)

On another note, here is a copy of the "Rules/suggestion list" in non-caps form for people read:

Rule 1, 10k or 20k galvos are a real rip off for graphics.
They are barely useful for beam shows at a reduced playback rate.


Rule 2. What you can do is dependent on how your frame creation software inserts blanking, anchor, guide, and other points to a image. Some software, the cheap or free stuff, can require you to insert these points by hand.

Rule 3. You can do a really great image with a 20k galvo pair at a 1' scan angle, but it is useless at 10 degrees. Plan your shows based on desired "throw" distance to the screen. Once you know what your hardware can do, you can adjust your style. However, getting the 30k or better scanners in the first place helps so you can use the ilda standard tuning for frame exchange.

Rule 4. Factory tuning of galvo scanners is done by a minimum wage employee. Retuning of everything but the potentiometers that calibrate the position sensor and output stage offset is often needed. Calibrating the position sensor at home is scanner suicide. Poor quality scanners can often best be "pretuned" using a square wave generator and a oscilloscope, while monitoring the position signal. This lets you push the damping to the max, as opposed to starting with the ilda test pattern. If your scanners are poor, work using the laser media pattern to get the speeds even between x and y galvos. This is done by looking at the diagonial lines on the lm pattern. If the diagnials "bow apart" your scanners are not tuned to match in speed on long jumps.

Rule 5. You will find beam shows are not as limited by hardware as graphics shows are, unless you are doing mirror bounces.

Rule 6. There is a max pointcount n, for a given galvo pair, that is dependent upon how you draw your images. N = 600 to 750 for traditional 30k scanners. N has to be determined by experiment for less capable scanners. N sometimes needs to be exceeded, and is very angle dependent.

Rule 7. If you want your images to have sharp corners, you have to add points leading into the corner, at the corner, and perhaps leading away from the corner. Hence the term corner points.

Rule 8. If you have big jumps in your image, add small amounts of points along the jump. It is ok to color those points black if needed.
These are blanked points, and they are useful.

Rule 9. If your changing colors, and your system supports it, add intermediate colors for a few points on each side of the color change. Ie if changing from blue to red, stick a magenta point in just before the change.

Rule 10. If a image has parts that are not revealed at once, or are blanked, ie if spelling out "eat at joes" one letter at a time, all the blanked letters are still scanned. This keeps the image brightness even when the hidden portions are revealed. This also goes for multiple tracks. If you have anything to reveal, if possible scan it before reveal. This also applies to "write out" and erase effects.

Rule 11. Laser art is a art. You can only learn the art if you create your own material. Video your work, and get it criticized by non-laser artists and a few honest audience members.

Rule 12. Never plan a show to use the full system scan angle. More scan = less possible speed = more flicker.

Rule 13. Rotoscope pictures from real life. Most software allows you to load a pic in the background. Break a video down to single frames, trace the motion of each frame by hand, thus the brain sees the motion cues it normally looks for.

Rule 14. All frames in a given animation should have about the same point count.

Rule 15. For beam shows, count to eight or sixteen on music with 4/4 time between changing effects.

Rule 16. Events synced to music must be within 1/4 beat. Get software that has 30 event per second resolution. You cant do a show with cheap software that has .1 or 1 second resolution on playback. If you have to, run manually instead of 1 second playback.

Rule 17. Manipulate your audience. Play "here comes the sun" when the house lights start back up after the show. The first songs or effects are the easy, simple ones, then build in complexity. Insert teasers to keep attention. The best laser effect i ever saw was in a planetarium. When the song "raindrops are falling on my head" was running, staff ran around in the dark with sprayers, misting water over the audience. No one but laser geeks go to a show just to see laser effects. Showmanship counts, even at a rave.... A graphics show should tell a story, and not just be animation eye candy. Storyboard your shows. If your software supports it, display the wave file to find beats and events. If it does not support it, have a second machine running something like "audacity" or "spectrogram" so you can find cues.

Rule 18. Black, or dark, is a effect, use it. Work with the lighting folks, not against them. Magenta lights look good with gream beams, use complementary colors between the lighting and the lasers.

Rule 19. If your gear is not 100% up to standard, you need to come up with your own tuning scheme, or use the older laser media pattern, and switch your artistics to more or less simple 512 by 512 outline drawings. This requires you to be a artist.

Rule 20. Practice, practice, practice. You are not doing any one a favor if you show up unrehearsed.

Rule 21, stock shows are nice, but alter them so they do not look "stock." i'm sure over half the planet has seen a certain pangolin show. I love "creation:, but it is over done

rule 22, if your show is not taking at least a hour per laser minute to create, figure out what you are doing wrong.

Rule 23, there are shows other then beam shows, and there are effects other then graphics and beams. Lumia is your friend.
So are gratings.

Rule 24. If two scan heads are doing the same beam show, invert/flip the x axis on one to "mirror" the other. It looks so much better.

Rule 25. If you have more then two heads, do 2+1 2 doing mirrored beams, one doing graphics. More then 2 beam heads close together looks like garbage.

Rule 26, manual cuing of effects is far, far better then any beat sensor or other means of just standing there when the machine does the work.
Know what a musical "coda" is when doing beam shows to techno.

Rule 27. Add potentiometers to your system to set image size and any needed position offsets. When you set sizes at the show in software, you loose resolution in your images. A few pro software systems take hardware steps to avoid this, but they are few and far between. Do not use the scanner amp potentiometers to set size and offset at the show. This messes with the tuning, and any sensor offset heats the amp, causing distortion and loss of lifetime. It is ok to add offsets while playing back using a summing offset opamp you build, but the using offset control on the galvo amp is verbotten.

Rule 28. Always bring backup hardware.

Rule 29. Always have a fun "oncore" or "ovation" show to run if you did well and the audience wants to stay. A favorite trick is to run a clapping hands animation during applause.

Rule 30. (michael's rule) you cannot make money doing laser shows.

Rule 31. Scrims and projection screens can be raised and lowered during a show.

Rule 32. Hazers work great indoors, then use the fog machine to add texture as needed. Fans move fog..

Rule 33. Safety and legality is job one

rule 34. Audience scanning only looks good when it is done right and safe. Too bright and it hurts. Its highly overrated.

Rule 35. You are the artist, the other crew and leadership at a gig may not have a clue about what makes a good show
remember that. On the other hand, they may have toured with floyd... So find out

rule 36. Always have a business plan and a show rider for your gear. Always invest back into your gear, and into marketing what you do. Save for a rainy day, and always have backup gear.

Rule 37. If a show is too big for you, turn it down or bid it out.

Rule 38, dont repeat effects unless on choruses. If you have to "copy and paste", at least add a color or mirroring modifier to the effect.


Rule 39, turn off the blanking when programming shows and some times when creating images. If it looks good with no blanking, it will look great with it. This is true of tuning as well.

Rule 40. Be aware that some show software can alter frames during display. This can happen with test patterns, resulting in reduced performance when tuning. In a severe case, it can cause chaos. Be aware of vector mode.

Bonus rule, galvos like sine waves better then square waves and stiff jumps, but that takes thinking on how to implement.
 
Looks much better, and I've already said they're good suggestions. As for my technical input here it is: Rule 1 (sentence 2), Rule 11, Rule 22, Rule 23, Rule 25, and Rule 34 (sentence 3) are suggestions, but some could impinge on creativity if taken as rules and others are just a matter of opinion. The rest is extremely good information from a true expert and worth paying close attention to. That's probably all I should have said from the beginning lol..
 
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Looks much better, and I've already said they're good suggestions. As for my technical input here it is: Rule 1 (sentence 2), Rule 11, Rule 22, Rule 23, Rule 25, and Rule 34 (sentence 3) are suggestions, but some could impinge on creativity if taken as rules and others are just a matter of opinion. The rest is extremely good information from a true expert and worth paying close attention to. That's probably all I should have said from the beginning lol..

I really wasnt looking for creativity and artistic value tips, I can handle that, rather some suggestions, based on a set of specs on a particular set of galvos, what are a basic set of rules, i.e. max point count per frame, scan angle, etc. to be used to get the best out of a projector, minimize flickering with the best possible graphics with what we have.


Heres an example of what I was asking. Take a race car, it has a specific high compression engine that requires a specific type of gas. The driver provides the "artistic" value, what I want to know is what type of gas do I need to put in my car?

Just like the race car has a set of basic rules and understandings on how to make it run well based on what components it is made up of, Im sure there is some basic set of "performance" rules on laser projectors. If there isnt, I find it hard to believe considering they have been around plenty long enough.

I know each projector will be slightly different, however, I find it hard to believe that "just play with it" is the only thing anybody can come up with.

Without knowing how to properly use a particular set of hardware, I think the artistic value will be little. Just like a painter cannot paint the picture he wants to paint if he doesnt know how to use his brushes.


Yes, your info is good, and much appreciated, although it still really didnt answer the question. I seen some hints in there, but thats it.


I apologize, I dont mean to sound like an a$$
 
Let's not argue semantics. We can see these "rules" as suggestions, "rules of thumb", guidelines, or even plain ol' rules depending on how strict you adhere to them.
 
@Sputnik: For the best graphics at the highest speed, don't exceed the rated speed or the scan angle that the speed was set at when the galvos were tuned. So if you see a set while browsing to buy that is rated at 20kpps@8deg, which means the set was tuned at 8deg, you wouldn't want to exceed that angle to get the cleanest output at the maximum rated kpps. Obviously running your software/hardware interface at the highest rated kpps will give you the least flicker possible on a set of galvos. Once you buy a set and test it to make sure it projects the proper looking test pattern at the rated speed and angle, then you can usually reliably buy more of the same set with the same results. Off the top of my head I'm not sure about what an "ideal" point per frame rate is for a given set of galvos, I've never really looked into it since I do mostly beam shows but I can look to see how some graphics frames run on 20k galvos and let you know what kpps ranges look best.
 
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Because its mostly automated in Pangolin and LSX, what I mentioned about guide points, anchor points, blanking points, and color points, is no longer mentioned much. But for optimal graphics you need to know about them.

Smaller projection angles allow for more points, and you get that by turning the signal size down with a potentiometer for each axis between the show control card and the galvo amps.
Software reduces image size by reducing the "bit height"" in the image, you loose resolution when you size down the image in software, unless you have the one card on the market that uses multipliying DAC chips, which is the QM2000 or the older Qm32. If you use potentiometers, you do not loose bit count in the image.


N = 500 to 750 points for a 8' 30K image, and it depends on quality, scan angle, type of scanner amplfiier, and tuning. That is a guideline. If you hand digitize you CAN do better then to autotrace in most cases.



When I hand digitize, I either scan in the material and load it as a BMP into the show software drawing window, or I use a Kurta tablet that holds a 12" x 12" image on paper. This is known as Rotoscoping, and is how older cartoons and Disney style movies were done pre CGi. So where I place the points, and adding the above listed types of points, allows me to cram in more points.

Galvos have a fluid, living, quality to them, and it depends on the tuning. So there is no FORMULA for what you want to know. Sometimes a "stiff" t uning on the galvo amps makes them great for beam shows, where a more "soft" tuning makes for fluid graphics. From what I've seen at five differnt LEMS, Asian amps are "Stiff" when they leave the factory. If I want a soft tuning I try for less damping and tune at a smaller angle.

Optimization software math/rules for galvos are just not published. It only exists in the heads of about 10 software people right now, so you'd be hard pressed to do better then to learn about the types of points, size of jumps, and the N=~750 max rule. That number comes from tests done by Pat Murphy, the Artistic Founder of Pangolin, who sold his half of the company to Bill Benner some years ago. I've been sent 3D images as large as 2000 points (Flicker City!!)

If you want really, really good graphics, you can split images across two scan heads, and run them as independent tracks in the software. Pangolin Basic or Pro, will easily let you do this with a pair or more of Quadmods in one machine. I've never tried it with a pair of FB3s, so how I doubt they would sync that well. If that needs to look good on anything other then a flat surface, I have geometric corrector cards and my software has geometric correction per scan head. So does nearly every other platform out there except "Sound Card Dacing"

LSX pro will let you do that as well, but I would use matched output devices, ie two identical RIYAs or two JC4BO cards.I would not try it with simple sound card dacs.


You can get away with more then that some times, as I have some carefully optimized images at 1100-1200 points used at a small angle.Those get displayed on Galvos with a built in notch filter. Lots of frames have more, lots have less.

As most people do not want to invest in programming graphics shows, the information you seek has to be relearned. Its drifting away.

The only book on the subject was published in 1995 to 2000, hand printed and bound, is 400 pages long, the graphics optimization chapter takes 35 pages, and the author is still alive, and has A. No interest in printing/binding more, and B. He would sue my ### off if I scanned it in and posted it. I dont blame him, that book was a work of love. I've never seen it on EBAY.

Laser-FX, the Light Show Handbook, L. Michael Roberts, is the author, and its hand published, so no publsher other then Laser-FX Ltd, Toronto Canada.
He bought a industrial printer and self published it, and sent it out to be bound.
Otherwise you have to go to a ILDA meeting or spend some time at a really big Laser show company that has a on staff animator to learn about it.

LMR is not related to me (My last name is also Roberts), but he was a good friend and mentor before he left to work on industrial lighting. He offered a weekend course on doing graphics for 250$, in 1990 Dollars, with 12 hour days spent on learning. It was worth it.

If you ask on PL, maybe some one will sell their copy of Mike's book.If your near Toronto, you can maybe look him up and see if he'll give you a class.

The Disney trained laser show animators are at companies in Toronto and Chicago, and both are friendly. One more guy, is in Pittsburg. Otherwise most people use "Autotrace" functions and 3D studio Max plugins.

If your software allows it, view the "hidden points" when doing graphics.

Open up whatever your software uses for "Projector Settings" and try adding, reducing corner points, and you can see what happens to your images. For each set of galvos there is a optimium projector setting that you find by hand, moving the slider.
It can change from artist to artist, too.

Steve
 
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hello every body
i need some info about needed frequency for create a square with two galvo.
 


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