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ArcticMyst Security by Avery

Need help understanding Scanning speed

Dec 9, 2015
Hello Guys!

I know it's been a while but I am back with another n00b question about scanners which I have yet to fully understand.

So lets say I have a set of DT 40's running through Quickshow. The 40k rating should mean that the highest scan speed at which the Ilda test pattern can be displayed correctly at 8 degrees is 40k, correct? As you increase the angle, the speed at which the same number of points can be scanned correctly is reduced as they grow further apart, but I can't find clear information on how this relationship works in laser software. Do you decrease the kpps according to a linear relationship to keep the scanners moving at the same speed as the points drift apart? Do you keep the speed the same? I have no idea despite owning a projector and Quickshow for over a year. I initially thought one used the test pattern to determine max speed at a given angle, but I am realizing that may be wrong. In the past I have just always scanned at a lower speed with larger angles. Any insight.


May 14, 2011
Maybe have a look at this thread--LSRFAQ explains some basic pro level details, relationships, and ILDA standards --see Question about Galvo Speed https://laserpointerforums.com/f47/question-about-galvo-speed-71998.html

From that thread:
"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 user.
KPPS became a marketing tool, and sadly, it has remained that way. Thus it is misunderstood, as is the pattern,"

Hope that helps a bit.
Last edited:
Sep 20, 2008
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