Question about Galvo Speed?

Bionic-Badger said:

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.

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LSRFAQ said:

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.

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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.

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ElektroFreak said:

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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