Question about Galvo Speed?

Ok, Im trying to understand something about galvo speed.


Say I have 10K PPS galvos (just as an example), which I take to mean they can handle 10000 points per second smoothly.

Now, I have a show, running at 30FPS. With 10K PPS scanners that means I can have 333 points per frame and it should play back smoothly, with fair precision.


10k/30 = 333.33 (333)


Am I correct in thinking that 10K scanners, a show running @ 30FPS should be able to handle 333 points per frame and play them back smoothly?

IIRC a 10 khz scanner Galvo can scan back and forth 10,000 times a second
at a certain angle. The smaller the angle the faster a galvo can scan to a
mechanical/electrical limit..
Projector guys.... correct me if I'm wrong...:beer:

Jerry

lasersbee said:

IIRC a 10 khz scanner Galvo can scan back and forth 10,000 times a second
at a certain angle. The smaller the angle the faster a galvo can scan to a
mechanical/electrical limit..
Projector guys.... correct me if I'm wrong...:beer:

Jerry

Click to expand...

Yes, that would be the case if they were rated in kHz, but they are not. They are rated in PPS (points per second).

That is unless they use them interchangeably, and 10K PPS = 10Khz. Which I dont think is the case, but I could be wrong. Thats what Im trying to get clear on.

That is correct Jerry. The scanner mirror can move from point A to point B at 10,000 times a second. This is usually 8°. I'm pretty sure the ILDA test frame is scanned at this angle.

When you do exceed your scanners capabilities, you'll know about it, especially if there is no music playing (your just testing). Curved lines will not meet up, there will be overshoot, and your scanners will make an awful noise.

Scanners are rated in Kpps - I think you may be confusing modulation speed on laser heads here - which is usually 10-30Khz, but some heads (445 on a flexmod) can go heaps faster.

in either case the less points it takes to make up a frame (i.e. optimising the frame to remove redundant points), the smoother it will scan, and it also means a more complex frame may work on slower scanners.

Finally this only bears true if your scanners are actually really rated to 10,000pps. Some chinese manufacturers just cant get it right (some wont scan at 15kpps even though they advertise them as such, and the REKE 500 was advertised with 5Kpps scanners, when it actually contains 10Kpps).

vk2fro said:

That is correct Jerry. The scanner mirror can move from point A to point B at 10,000 times a second. This is usually 8°. I'm pretty sure the ILDA test frame is scanned at this angle.

When you do exceed your scanners capabilities, you'll know about it, especially if there is no music playing (your just testing). Curved lines will not meet up, there will be overshoot, and your scanners will make an awful noise.

Scanners are rated in Kpps - I think you may be confusing modulation speed on laser heads here - which is usually 10-30Khz, but some heads (445 on a flexmod) can go heaps faster.

in either case the less points it takes to make up a frame (i.e. optimising the frame to remove redundant points), the smoother it will scan, and it also means a more complex frame may work on slower scanners.

Finally this only bears true if your scanners are actually really rated to 10,000pps. Some chinese manufacturers just cant get it right (some wont scan at 15kpps even though they advertise them as such, and the REKE 500 was advertised with 5Kpps scanners, when it actually contains 10Kpps).

Click to expand...

That still doesnt really clear anything up.

Im not referring to laser modulation speeds, rather scanner speeds which are rated in KPPS, and what that is really supposed to mean.

Complex answer about why the ilda pattern exists.

Sputnik77 said:

That still doesnt really clear anything up.

Im not referring to laser modulation speeds, rather scanner speeds which are rated in KPPS, and what that is really supposed to mean.

Click to expand...

=================================================

What the definition is based on is the ILDA test pattern. There is no easy relation between Kpps, Points in a image, and scanner bandwidth. Get this, the ILDA pattern is all about tuning the amplifier to display interchangable images. That is basically it. It is NOT a easy galvo bandwidth measurement.

Sorry, but there is NO easy way to relate mechanical KPPS to physical bandwidth. There is for the optical side, for a one update per point light bandwidth, F = 1/KPPS time.
So one optical point at 30K is about 12 uS. In reality few images change one color per point.


A 30 KPPS scanner sucessfully VISUALLY scans the ILDA test pattern at a DAC update rate of 30,000 point update commands per second. It cannot do 30K mechanical jumps per second. Since you have Nyquists sampling law, your already at a max of 15 Khz, since Nyquist states the waveform at best can contain frequencies up to 1/2 the update rate. In reality the galvo has far less bandwidth then that.

You cannot assume KPPS/POINTS in frame = bandwidth for the motion component. Its not. The scanner is modeled by a second order equation with about 8 terms. For this discussion, it is a variable bandwidth low pass filter because it has mass and inertia, and resonances which show up as ringing.
We run it in ballistic mode, and have to keep it just below its first shaft resonance.* (*Unless its a better amp and has a notch filter or filters)


In reality, no mechanical scanner short of a MEMS mirror does 10,000 discrete steps per second, and the highest speed resonant scanners are roughly 8 Kilohertz for a pure sine wave, but they cannot do discrete steps.

This gets complex if you look at a galvo data sheet because there is a small angle step time and a large angle step time.

The modulation bandwidth of the laser is far faster, in most cases then the galvo and it needs to be.
.

There are two different issues here, a small jump, which is very fast, and a large angle jump, which is quite slow. The Galvos jump time changes with the commanded angle in a less then linear way.

There are different kinds of points, anchor, blanking, guide, all of them are inserted in a image to do something with scanner motion. If I'm doing a right angle turn in a image my software can add anywhere between 3 to 7 points at the right angle turn to sharpen the turn. The ILDA testpattern is a complex waveform because of the added points, so its not 1/KPPS for the scanner response.

Your not dealing with a linear jump, its a ballistic response, hence the added points in the waveform.

If you look at a Cambridge data sheet for a fast laser show scanner,
You see that small angle, with a defined mirror mass, is
100 uS

REF: Cambridge Technology: 6210H Moving Magnet Closed Loop Galvanometer Based Optical Scanner

But they do not tell you on the sheet what the angle is, you have to call and ask.

The time for settling to a new point changes with the size of the jump angle above a certain angle.

That 100 uS number is .1 Millisecond, which looks like 10khz, but its not, because you do not know the angle. I assure you its smaller then a 1 dac step move on a typical screen.

If you want to really know the bandwidth of your scanner, you have one way.
Hook up a oscillsocpe, define the angle you want to move, and input a step to command that motion. You then wait till you see about three cycles of damped ringing in the feedback signal just past where the galvo hits the mark. That is your
Step time. 1/Step time = your bandwidth at Angle X.

You'll find it changes based on the history of the scanners motion, so the easy way is to just input a step and define where the step is considered stopped.
But that does not tune the scanner amp for vector graphics, that tunes it for a fast short jump. It does not give you a good tuning for large jumps.

This means "There are lies, damned lies, and Galvo data sheets." Sorry Mr Twain for paraphrasing you.

So the way to solve this, in order to rate a galvo, was to have a team of professional electrical engineers at big laser show companies, come up with a test pattern displayed at a constant angle.

The actual small signal bandwidth test in the pattern is the circle in the square, because it does not have added anchor points or guide points, except on the corners of the square. So the circle is truely ballistic while the square is forced to be very square and well defined. When the circle is just touching the insides of the square, that is the scanner known bandwidth point. However the mathematical relation between the circle and the galvo small signal bandwidth has never been published. I can ask Casey Stack to see if he remembers what it is.

Factoid, if your galvos and color system can display the ILDA test pattern at a certain PPS speed, you can then interchange images. That is all that the PATTERN does. If you can get bonus PPS over the 24K or 30K standards, thats groovey. There used to be a 12Kpps standard for General Scanning galvos, which were used pre Cambridge. Then a genius in Florida found a way to force GSIs to speed up to 24-28K using a highly specialized galvo amp. The same new amp structure could force 60K out of a Cambridge at very tiny angles, hence the 60K (its actually 57K in physical practice) so called standard. A 60K galvo needs a really stiff shaft that does not resonante so fast. That costs more.

The ILDA pattern is a standard for easy evaluation of a galvo speed, based on definitions, for operators and artists, not engineers. It gives you a way to NORMALIZE scanner response across the omniverse of scanner users, and it does not 100% rate the mechanics of the galvo. It is just a way to get rid of human subjectivity and interchange images.


If you open up the angle, you have to slow the PPS to have good images. No way around that law of physics.

8 degrees is a nice compromise angle between small jumps and large jumps, that is why it was picked.

Before the ILDA standard, there was little or no way to interchange images across different software, or even different users, unless you "PULLED" points, which means going in by hand and editing the image to adjust to your companies standard scanner tuning. This was because no two companies used the same galvo amps, they either bought them or made their own. The ILDA test pattern allowed standardization of the amplifiers for today's users.



KPPS became a marketing tool, and sadly, it has remained that way. Thus it is misunderstood, as is the pattern, and the same argument has been going on for years. I hope this helps, because I watched this happen.

We've hit a physical limit in galvo speed. Only in the past few years have DSP chips became fast enough to tune the galvo response in real time, and that has slammed the upper speed limit into a physical brick law.

Funny thing, a 60 KPPS scanner really just gets used for wider images at 30K.
That is all it does for you, unless you have a very small, detailed, graphics image.

Much above a certain laser modulation rate, there is no point in having a faster laser. A PCAOM did about 150 Khz, and that is about as fast as you ever need to get.


I'll scan in the equation of motion for a older galvo in terms of time,
and post it here in a few minutes. Hopefully it will let you see why you should just trust the pattern and its numbers, unless you want to have your own amp tuning and no way to interchange images or evaluate what you can do before you get to a show venue.

Sorry, but its a complex mess, and there is little documentation available about why some choices were made.

Its all we have to simplify a complex multi-variable problem.

If you want to understand more about galvo response, read "Tuning Stratagies" in the Mini-Sax manual below, then try and figure out how to tune without the ILDA pattern, and yet exchange images. That should give you some clues. (Note this is engineering tuning, not for laser shows.).

Dr Lava's measurement is about the same as mine, for a really good 30Kpps galvo at 8 degrees, the small signal bandwidth(AMP PLUS GALVO) is about 2.4 Kilohertz.
But the laser modulation has to be much faster, because it is effectly oversampling the galvo speed about 8 or more times.

Hopefully this is the last time, after 20 years of doing this, that I will have to type this all out again. It needs editing, badly.

Attached images are crude scans using a cheap camera from a complex book.

Simple citation for images: Marshall, Gerald F. Editor, Laser Beam Scanning, 1995, New York, New York, Marcel Dekkar Inc


Useful Links:

Laser Show Systems - Scanning Systems - www.LaserFX.com
Laser Show Systems - Scanning Systems - www.LaserFX.com
http://www.camtech.com/archive/176-25016_MiniSAX_Manual_G.pdf



Steve

QUOTE: Am I correct in thinking that 10K scanners, a show running @ 30FPS should be able to handle 333 points per frame and play them back smoothly?[/QUOTE]
---------------------------------------------------------------------------------
No, see my complex post above as to why.

For good laser software with a well tuned galvo, ~750 points is the reccomended maximum for a good image with low flicker. You can get away with more or less 500 or so for decent 30K scanners. Some images have much more then that, and the user has to tolerate flicker.

There is a caveat to this. Some images cannot be measured this way. Here is why:

Software with computed " vector" output can resize the point count in real time and do better. Pangolin offers a choice between normal and "vector" output in its newer software. Vector frames only store the changes in the image, and the software computes the data sent to the DAC on the fly. Data stored as .ILD is not a true vector format, as the file contains all points to be scanned. "Vector" systems convert ILDA files to just the changes before playback and run them through the computation process.

Vector systems can better exploit the galvo for graphics. However some older frames just do not look good in vector mode.

Steve

Re: Complex answer about why the ilda pattern exists.

LSRFAQ said:

Steve

Click to expand...

Wow, didnt expect all that, and I appreciate it.

However, it really doesnt translate well in to how someone can take a basic set of specs (assuming the specs are accurate) and create a frames that perform well.

While I do understand most of that, and how it relates to galvo performance, and tuning, Im still trying to understand how the basic set of specs typically seen with a cheap set of galvos, can be translated into how I design my frames.

While that information may be useable to those building amps, galvos , really high end projectors, and the most professional laserists running $100k projectors and doing shows at the largest venues, it does not work well for us hobbyists buying/building relatively inexpensive projectors who simply want to make the best of what we have with a few simple rules.

Re: Complex answer about why the ilda pattern exists.

While that information may be useable to those building amps, galvos , really high end projectors, and the most professional laserists running $100k projectors and doing shows at the largest venues, it does not work well for us hobbyists buying/building relatively inexpensive projectors who simply want to make the best of what we have with a few simple rules.[/QUOTE]

It matters more then you think, because you then need to retune the low cost system as best as you can. In fact it matters more, because you then know how to push your hardware, or baby it so it does not melt. There used to be frames that could really damage poorly adjustable scanners, and I imagine this is easy to do with freeware/cheapware in some cases.

OTEAHY, WE CAN DO THAT, TO A POINT!

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.


Does this help? Anything more then that and you either need to visit me for lessons, or my best friend will kill me for releasing trade secrets!

Steve

Hey Steve....
Thanks for the info.. learned a lot of galvo stuff on post #6
that I didn't know...

BTW... ALL CAPS is a Biach to read so I skipped over it...

It probably has some more great info in that post as well...:cryyy:


Jerry

Re: Complex answer about why the ilda pattern exists.

LSRFAQ said:

While that information may be useable to those building amps, galvos , really high end projectors, and the most professional laserists running $100k projectors and doing shows at the largest venues, it does not work well for us hobbyists buying/building relatively inexpensive projectors who simply want to make the best of what we have with a few simple rules.

RULE 1-40 blah blah

Steve

Click to expand...

First off, that's a WHOLE lot of "rules" for something that is an "art" and therefore should be mostly up to the artist. Many of them ARE good ADVICE though, not rules.

Second, easily half of those "rules" are either optional or just someone trying to insist that the rest of us are doing things up to their "standards". The nice thing about an art is that the artist is allowed free creative reign over their art. If an audience is happy and enjoys the show that is all that matters.

One thing I've found out in the 3 years I've been doing shows is that the only people who care about lasers like laserists do ARE LASERISTS. The audiences are easily pleased in most cases, and they could give a crap about things like whether the beams/lines they see are the very thinnest possible, or if the white balance is slightly golden or bluish..That's not an excuse to be lazy, merely a reference to the aforementioned creative license. There is a LOT of room for creativity free of the constraints of "rules". There is nothing wrong with trying for the best results that you can get, within reason and cost constraints. That should be encouraged.

Each and every day those "trade secrets" you refer to are disappearing.. with any luck we'll have them all out in the open one day. Laser shows are magical in the effect that they add to an environment, but they aren't MAGIC. Technology marches on, resulting in lower prices and more easily accessible technical information so a lot of this "secrecy" that old-school types believe so strongly in for the purposes of protecting their profit margin and their ability to overcharge their customers is being released publicly as fast as many of us can make it happen. Technology is what it is. Lasers and laser shows are NOT going to be exempt from the effects of the standard progression of the technology involved, no matter how much old heads want it to be. It's not 1976 anymore.. sad I know, but nowadays lasers are everywhere.

Apologies if I'm off-topic.

Re: Complex answer about why the ilda pattern exists.

ElektroFreak said:

First off, that's a WHOLE lot of "rules" for something that is an "art" and therefore should be mostly up to the artist. Many of them ARE good ADVICE though, not rules.

Second, easily half of those "rules" are either optional or just someone trying to insist that the rest of us are doing things up to their "standards". The nice thing about an art is that the artist is allowed free creative reign over their art. If an audience is happy and enjoys the show that is all that matters.

---------------------End Quote-------------------------------

All that tech info was available in LFX and ILDA newsletters, which are on paper and pre-net. At the time LFX was sent to any one who asked, because it was Advertisement supported and a labor of love. The ILDA stuff at the time was a open standard. Only much later did the board close the standards to just members for a while. However if you phone up ILDA or Email them a PDF shows up today at no cost. The test pattern is very old, but it works today because it was well engineered in the first place. There was nothing trade secret in the technical post. Its technical history that has a limited market and so has not been written up. I took the time to write it up becase the question is a DAMN GOOD question to ask.

As for the rest of your post:

God, I hope you never face a proper corporate client who wants perfection.

I'm glad you want to see the art reduced to useless point and click.

I went to school for two months in Canada and several weeks in Florida with two major laser show companies to learn the art. at my own expense. I was 18 at the time. I make my living with lasers, and my clients, both scientific, and laser display, want the very best.

I'm glad you have a day job and do shows as basically a self paying hobby.

I'm also tired of you having to inject your contrarian opinion every time I post on standards, doing business, and doing a good show. You rarely contribute anything remotely positive or technical when you do so. Why did you not give him suggestions he could try to use his system to the max?

You have a canned lighting company client that pays your bills and accepts your shows, because you are low cost and they can exert control over what you do.Your regular job subsidizes their ability to do laser effects. My stuff is out for bid, and is laser only, which means I have to perform to a very high standard. If I dont get things right, and like all humans, I do screw up, the whole world hears about it. Its a problem when you do world class stuff. I'm glad that works for you. It does not, for many of us.


I've scanned images on the side of the largest Banking firm in Manhatten, I think I know what I do for a living, well. Those images were a preview of a 13 million dollar sign install. Those posted rules make that sort of thing possible. Constraints on that gig included less then one hour setup and takedown per Homeland Security rules, and no rehearsals of the actual images, least the local papers/cell phone media, saw the images before media time. All done while 37 stories up and in the rain, from a rented site across the street. The system had to run on available 110, and the images were 16 by 80 feet. We were not allowed a parking space, the gear all came up in backpacks. The Banks his CEO was flying around the building in a helicopter seeing how his new sign would look. He flew in from London to see it. Being on the small team that could pull something like that off, means I've earned my stripes. PS, they use a very specific light BLUE in their logo, and we had to match it. Not to our eyes, but to the eyes of their team of producers and standards folks.. That was a "witch" to do with two different non-ion projectors.

As of last month, a year later, the sign is up, and it fits between the mintons and minions in the glass structure, exactly as in one of the projected design looks designed by the client.

Quoting Barbara Streisand, who got it from Stephen Sondheim

"Art is not Art if its Easy, The Art of Making Art is putting it together"

I'm sorry that you will be happy with your goal for less artistry in a few years.
This is why no one wants to pay for laser artwork any more.
That attitude has made it cheap.

The OP has made it clear he wants to achieve perfection. He can take what I wrote with a grain of salt, or learn from it. I'm sorry your lazy, and no longer have his spirt and desire to learn, and improve like he does. Hes asking a very educated question to earn understanding and to do the best with less.

EF, I love your attitude towards trade secrets. Its all right if YOU have them, but it is NOT OK for the rest of US. The world runs on competitive advantage, even the Coldl War Soviets with their controlled economy had competitive bidding and individual "design" agenices that bid against each other and had competions with prototypes.

Sputnik, I'm sorry, you just got dumped into a long running stupid attitude thing from LPFs resident "EXPERT", who learned what he knows from folks on another open forum. One that is "SNOOTY" in his opinion because we have standards for our beloved art. We bent over backwards with him before he excluded himself from the 2,000 member "CLICK".

Your criticizing the guy who has done more to open things up then any one else, except perhaps Michael, who was before your time, and Bill.
Is there not something funny about that?

Dang, once again I let you prevoke me.



Steve

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Our audiences have yet to complain about our shows (QUITE the opposite in fact), and the people I work for have yet to complain about our pricing.. plus the pricing quoted by the so-called "pros" makes it VERY easy to get and keep business. IMO it's time for a revolution in the world of laser shows, and I intend to base our business on showing customers how much value we can give them, while at the same time supplying the very best shows we can and maintaining our ability to improve our shows over time.. NOT on fattening my wallet as much as humanly possible per gig in a nearly criminal fashion. Those who want to play that game are welcome to.. they'd better hope their clientele never hears about our rates though.

Steve, I might post alternate opinions, but I don't believe that to be a problem. You yourself called this an art.. so is it or isn't it? Isn't what art consists of up to the artist and the opinions thereof up to those who view the art? If both the artist and the audience are happy, where is the problem? The problem is with people who don't believe that art is art unless THEY say it is. I've heard the whole "gaining the respect of your peers" song and dance before, but unfortunately a good many of the other US laserists that I've had the misfortune of associating with are not quality people based on the way they treated me and others in THIS (LPF) community during our interactions, therefore they have not gained MY respect. I don't kiss ass Steve, and there isn't a soul on earth that I cannot stand directly eye to eye with, whether the other person feels the same way or not is of no consequence. Fortunately for the artist and their audience, the opinions of "critics" and the word of other artists are not the most important thing.

You label our efforts as a company as nothing more than a "hobby", however I feel that I should point out that the reason you likely feel that way is because we do not feel the need to justify or explain our pricing, legality, hierarchy, safety or even share our company contact info with ANYONE in the professional laser community. I'm not interested in the US professional laser community. ILDA is more trouble than it's worth. Associating with our "peers" is also more trouble than it's worth, and so we have a better idea: We are trying to create a whole new value oriented laser show service whether the rest of the professional community approves or not. This is something that has not been done before to my knowledge. Because this is new ground, AND because of the fact that our shows are constantly being improved, we are very much still learning whether you, Steve, say we are or not.

So far you've been most helpful to the OP.. my only real issue was with the use of the term "rules" in that one post of yours instead of suggestions. You are welcome to downplay any expertise I do have, and I will concede as I have before that you have years of experience with lasers on me.. but as I've said before, knowledge and expertise do not give someone license to tell others what the "rules" are, especially regarding an art form, since suggestions are far more proper. Some of those "rules" you posted clearly denigrate techniques that have been used by others which are not necessarily bad or wrong except in YOUR opinion, which isn't fair to do when dealing with abstracts. You are merely crowding their "canvas" with restrictions when it could be wide open and clean as a whistle, ready for the artist to take his art where he wishes.. That's was all I was saying. We are all entitled to our opinions, AND we are entitled to disagree with those of others.

Since you responded to my post within your last post, I'll double post. PL cannot claim even the tiniest bit of credit for helping me learn. There are only a couple people who ever did anything to help me on PL, and they know who they are.. I would not consider those people as having "bent over backwards" for me however because I never asked them to.. in fact I almost never asked questions on PL, either via PM or in the open forum. What I learned I learned from reading every laser resource I could find, whether forum or otherwise. A large portion of the US pro community insulted me and my opinions AND my intelligence within days of my becoming a member there. Because of the fact that I never forget how I am treated by others, I will never respect that community. The PL community had a chance to earn my respect (and they still have opportunites to earn the respect of any new member) but they blew it right off the bat and still blow it routinely with new faces that arrive. In my case respect was never to return.. and now here we are.

LSRFAQ said:

Jerry, sorry, I am dealing with new glasses, I just almost poured a bottle of hot mustard sauce on my Salad. Until I get used to the eye strain, ALL CAPS looked good at 2 AM on a ultra hig res 15" monitor with LPFS usual fonts.

I did not mean to "Shout", I was trying to cope with eye strain.

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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.