OBNRacerMan wrote: ↑14 Jan 2023, 13:18
As far as I know, only cameras with Global Shutter can fully and correctly work with a synchronized projector. And such a setup, in principle, will allow using a stationary SLS scanner as a manual one (if the cameras have sufficient speed - 50-500fps)
For cheaper cameras with Rolling Shutter, such work is problematic or impossible at all.
P.S. Also keep in mind that the cost of cameras with Global Shutter (at the same resolution) can be 3-5 times higher than cameras with Rolling Shutter
We can use Hardware triggering with any cameras, including Rolling shutter and Global Shutter cameras. But for a SLS scanner and even a hand held SLS scanner we don't need global shutter and high frame rate cameras at all.
Hi OBNRacerMan
nice to see your comments again
.
you are one of the most experiences persons in this forum, but
these information you shared in this post is not correct at all.
Global shutter cameras are for frame rates higher than 200 fps and for capturing some objects which moves very fast (like a fan blades rotating at 500rpm). it refreshes the sensor faster than a rolling shutter.
But for SLS scanner we don't even need more than 30fps. so a global shutter doesn't have any advantages here else than wasting money.
I think you confused SLS scanners with hand held laser scanners. In a laser scanner you should use global shutter cameras and it is not because of triggering or synchronization, but it is related to the method of sweeping the surfaces by the laser lines.
That means for a laser scanner, each frame of scan only capture few points of the surfaces (it capture only the edges of the laser lines), so for capturing whole of the surface you should move your hand fast, so you need a high frame rate global shutter camera (usually more than 200fps). Also you can use lower frame rate rolling shutter cameras, but you can't move your hands fast and scanning time increases significantly. On the other hand, SLS hand held scanners capture a large area by each scan shot, so you don't need to move your hands fast to capture whole of the surface.
Another subject is that if you even have 200 fps cameras, you can't use them for SLS scanning (you can't use more than 100 fps for SLS scanning and getting good scans. maximum acceptable value is 60 fps). I know the reason, but can you guess it too? if no, I can explain by myself.
About your second sentence, by using Hardware synchronization you can have a
semi hand held scanner.
So we can use Hardware triggering with any cameras, including Rolling shutter and Global Shutter cameras. but for a SLS scanner and even a hand held SLS scanner we don't need global shutter cameras at all.
I should mention that I've also tested my hardware trigger circuit even with my
9fps Basler daA2500-14uc cameras, and I received excellent results. These Basler cameras are color and they have rolling shutter too.
now I'm using my hardware trigger and synchronization circuit with my Daheng MER2-630-60U3M cameras. They are excellent. Scan speed is incredible and now I'm working to reach my goal, a professional hand held scanner
If you want, for clarification, I can upload any documents you need, to show you how well my hardware triggering option working in my modified version of FlexScan3D
.