Scanners Side by Side Video

[Datsurb]

I made a quick and dirty side by side shoot with 3 projectors. All with different scanners, but hooked up to the same FB3 and daisychained.
Left is DT30 Middle is my Pluto with the PT40 and Right the really cheap AL25K from Goldenstar.

I promissed to post something like this a while back. Not the most complex show for obvious reasons.

https://www.youtube.com/watch?v=emOl...ature=youtu.be

[dnar]

Not really a fair comparison as each set has different lasers. Looks like the DT30 and PT 40 are close, the 25 obviously doesn't have the scan angle understandably. Not really sure this proves anything.

A bit like comparing apples, oranges and lemons.

[Datsurb]

Not really sure this proves anything.

A bit like comparing apples, oranges and lemons.

This shows that also a cheap scanner is capable of delivering a decent result. A lot of people are wondering what the difference really looks like, and the show is more or less what a "true amateur" would make or use. For the more professional laserist, the test is of less interest.

Interesting comparison to the fruit-basket. :-)

[dkumpula]

Yeah, we tend to post pics/vids of ILDA 30K test patterns to see what is technically correct without considering the real-world differences that an audience may / may not notice.

Most of the cues chosen for the video were understandably more suited towards beam shows and there admittedly isn't a huge difference between the three even though the price varies by three-fold. That said, beam projectors should scan wide IMO, which means the AL25 is really at a disadvantage here.

On a related note, I noticed that my prior favorite for cheap-n-cheerful 40K graphics (the PT-40Pro) is no longer on the Lightspace site. Instead, there is a new series which appears to have some similarities to the Compact 506's: http://www.eightonlight.cn/products/.../0418/342.html

I'd like to get my hands on a set of these for comparison with my 506's as the Compact 506's are (after 2.5 years running) not being sold bundled with amps. (!!)

-David

[dnar]

I would like to see comparisons of identical scan rate scanners, with the same lasers, yet each tuned to identical scan angles and optimal tuning for each set.

[masterpj]

You can increase the scanner size by turning the size potentiometer on the AL25k. They are not really that well tuned from the factory at all and they scan much wider then what they are set to from the factory.

[mixedgas]

I would like to see comparisons of identical scan rate scanners, with the same lasers, yet each tuned to identical scan angles and optimal tuning for each set.

No, You would really like to watch the output of the position sensors, integrator, and differentiator, on a storage scope, scanning a square wave. Then feel the bearing noise by hand turning the shaft..

Come on Dwayne, you know better then that... Its an impulse response and bandwidth thing. Steve

[masterpj]

No, You would really like to watch the output of the position sensors, integrator, and differentiator, on a storage scope, scanning a square wave. Then feel the bearing noise by hand turning the shaft..

Come on Dwayne, you know better then that... Its an impulse response and bandwidth thing. Steve

Mixedgas I can do this for you. I have a 100mhz digital scope here which can also record to avi format in which I can make gifs or mp4's from showing data in slow motion as well.
I have no idea where to probe on the drivers but I could just probe into both position sensor lines incase that helps.
I have AL15k and AL20k
Galvos are identical for both. The difference is in the driver and the extra accesories you get like an ilda in and out connector and a connector with dipswitches... really not a big deal as you can just tap into the other board and feed it the X and Y signals

Regarding the shafts and their bearings.. they are very solid actually.. little resistance as well and they are much better then other low cost galvos I have seen on the market which can have the feeling like they have some drag because very cheap and bad bearings. Also these are very small galvos!

The PT40's will be the best of this bunch and the DT30's will be as well but I can actually fairly say that the AL20 and AL25k wont be far off from DT30's when you spend time in tuning them and doing some more mdos to them. It doesn't use a lot of power either... about 1 amp on each differential end at just 12 volts and the driver allows as much as 18 volts to be used to get more gain and thus tune up the system further!
Do not surpass 18 volts really do not... the caps are not rated for higher then this.

[Colin290]

This is interesting stuff.... So with the same size & position setting being sent from FB3 to all three projectors, the higher performance ones are naturally scanning wider..

So if I was to daisychain 4 projectors.. 2 running ALK30 (my own GS units) and 2 running PT30 (considering buying 2 Club 2000 units) would the PT30s give a wider beamshow than the ALK30s?

And how does one go about tuning scanners..does it involve a lot of tweaking around inside the projector or is it a straightforward sort of task?

Colin

[Datsurb]

I have no idea if the ALK30 will be the same size as the PT30. I will probably be a way to tune the scanners to throw more or less the same size from the same distance. From what i have been reading here at PL, there is not a stright forward way doing that. All the pots on the scanner amps are used to tune the final output, and adjusting the size will result in adjusting all the other pots to balance the signal.There are some descriptions here at PL on how to tune scanners, but I have not come to that point yet myself.

Goldenstar does not sett PT - scanners, so i would not count on data from them in this matter. It might be some members here having both scanner sets, willing to set tjem up side by side to compare size.