Some tweak for close-up calibration with dual cameras

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OBNRacerMan
Posts: 12
Joined: 12 Aug 2019, 09:46
Location: Obninsk, Russia

Some tweak for close-up calibration with dual cameras

Post by OBNRacerMan » 20 Aug 2019, 07:23

At some point, I was faced with the inability to calibrate in a dual-camera configuration if the distance to the panels is very small (and only one side of the calibration angle normally enters the field of view of any camera)
I decided this by turning the calibration angle to the side. Then he got the opportunity to calibrate from any close distance at which the projector can focus.

For me, the working distance (from the projector to the table) for scanning small objects is now 130mm and the 30mm calibration panel is used.
20190724171116s.jpg
Side view
20190724171215s.jpg
View from program window
I once shared this little tweak in other forums (including the HP 3D scanner forum)

It may be useful to someone.

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Micr0
Posts: 339
Joined: 15 Nov 2016, 15:20

Re: Some tweak for close-up calibration with dual cameras

Post by Micr0 » 22 Aug 2019, 12:48

OBNRacerMan wrote:
20 Aug 2019, 07:23
At some point, I was faced with the inability to calibrate in a dual-camera configuration if the distance to the panels is very small (and only one side of the calibration angle normally enters the field of view of any camera)
I decided this by turning the calibration angle to the side. Then he got the opportunity to calibrate from any close distance at which the projector can focus.

For me, the working distance (from the projector to the table) for scanning small objects is now 130mm and the 30mm calibration panel is used.
20190724171116s.jpg20190724171215s.jpg

I once shared this little tweak in other forums (including the HP 3D scanner forum)

It may be useful to someone.
Of all the panels and camera/projector configurations I've tried, I never though to try to turning the calibration panels sideways. Inverted, yes. But not sideways. This could solve a number of problems. Thank you for this idea.
µ

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OBNRacerMan
Posts: 12
Joined: 12 Aug 2019, 09:46
Location: Obninsk, Russia

Re: Some tweak for close-up calibration with dual cameras

Post by OBNRacerMan » 22 Aug 2019, 13:30

It is possible (I cannot verify this) that such a calibration option will be incompatible, for example, with an automatic rotary table. With this position of the calibration table, the program thinks that the cameras are above and below the projector. Therefore, the scanned object is also turned to the side. With manual or semi-automatic gluing, this does not lead to problems (just get used to the fact that the scan also lies on its side :D )
Most importantly, with this arrangement of panels, I can now scan very small objects (such as coins)

martan
Posts: 29
Joined: 23 May 2018, 19:18
Location: Sweden

Re: Some tweak for close-up calibration with dual cameras

Post by martan » 23 Aug 2019, 10:00

Must try that!

Thanks!

:-)

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