Laser Comparison

[Norbert]

Hi there...
I spend the last two weeks with comparing the lasers I already got with the red and the green focusable from the DAVID-shop.
I finally purchased the green focusable laser and maybe you are interested in my testing results...

First of all: The red focusable laser from the shop and the red focusable from dealextreme gave the same results so I stopped testing this one very early and continued with the green one.

And here's a comparison between a scan with the focusable red laser from dealextreme and one made with the green focusable from the shop:

Btw. my Obelix is about 135mm tall...

[Norbert]

After that I tried to focus the green laser as well as I could to get even better results but that didn't work. I could get a linewidth of about 1-2px with some extreme camera setting but that didn't help.
So I did a test with my old modified green laserpointer which I didn't used for a while because of the very thick line it produces. The result was amazing: I got the same good scanning result!

So the linewidth doesn't seem to be as important as I thought. The big difference was switching from the red to the green laser.

[Khalid Khattak]

Agreed
Its due to u get double the details as compared to Red laser.

[Norbert]

Yes, though this is not new to us I was really impressed that I could get the same detailed scan with my laserpointer.
Next I tried to scan a smaller object to see if the results remain the same. And here's the difference between a focusable and a non-focusable laser. I couldn't get a good result with my laserpointer but with the focusable one from picotronic.
This is the object I scanned:

And this is my scanning-result (made with the focusable green laser):

Btw. this is the result from my Obelix-scans:

[Khalid Khattak]

Norbert
This is very very informative topic to all of us... Thanks for sharing your great work with all of us... I think your camera also play a great Role in getting such a high details!!!.. Are you using Logitech 9000??

[Norbert]

I also made a comparison of the laserlines I could get with the lasers I used:

The linewidth of my focusable lasers is about 0.2mm, the lasers from dealextreme gave different results (but all of them are good, the thinner one is ca 0.12mm!) and my "old horrible" green laserpointer has a linewidth of ca. 0.9mm.

So throw away your red lasers and grab' a green one, no matter if focusable or not...

Thanks again for Mattia and Walter for helping me here.

[Khalid Khattak]

This is the best thread..Keep it expanding...I have a Green Laser Pointer (10mW)... Can I convert it into focusable line?.. I am planning to remove the focusable Mechanism out of red laser and install it on my Green Laser..

I love You Robert for such a beautiful work:)

[Norbert]

oops, forgot...

Yes, all scans were made with the Logitech Pro 9000 with 1600x1200px @ 5fps ( I tried to get the best possible result) but that wasn't even necessary. I reduced every single scan of my Obelix twice in Meshlab so DAVID could handle all scans together. So maybe I could have scanned in 800x600px to get a similar result. This scan was made with the red laser still.
I think I will scan with 960x720px in the future. 15fps sounds more friendly than 5fps...

And... the green and the red lasers have different optics so it's not that easy. Tried this already...
But: the red dealextreme lasers and my green laserpointer have the same thread (M9 x 0.5mm) so I could easily change the lenses between them and use the line generator lens from the red laser... and I'm sure you can make a focusable green laser from a laserpointer.
I'm still playing around with them...

[WalterMo]

Thanks Norbert for your fundamental work.
It's interesting and important to have a direct comparison of scan results of different kind of lasers. And your scans are really perfect. It's nice to have a member on this forum who not only likes to show scans but also spends a lot of time (and money) in essential investigations.

By the way: How do you move the lasers? By hand, DC motor, stepper motor or kitchen timer?

Thanks,

Walter

[Norbert]

This is really very kind of you all. Thanks again.
The laser is rotated by a DC motor with a worm gear. It moves the laser up and down several times. Just improvised atm but it works...

[superrune]

Interesting comparison. I can't see these brand names (picotronic, dealextreme) in the David shop, were all of them purchased there? I am starting to regret now that I ordered the starter kit and its red laser...

Judging by your comparison, the 'dealextreme focusable B' seems to have then thinnest line. Wouldn't that be the best laser of them all?