Calibration Boards

Discuss about cameras, projectors, calibration panels, turntables etc.
mading
Posts: 130
Joined: 31 Jan 2017, 13:09

Re: Calibration Boards

Post by mading » 21 Jun 2018, 19:04

Now I have to know why I got 0.18 with original David and the same cameras! :?

I saw you use also a vertical angle. Would you like to share your hardware setup?

I'm looking for a wider Arca style bar: mine is Ok for one camera but a little bit short for two.
HP 3D scan, Acer K132, LG PF50, 2x DMK23UX236, 2xComputar M1214, David Calibration panels, Melamine panels, DIY rotary table

User avatar
Micr0
Posts: 393
Joined: 15 Nov 2016, 15:20

Re: Calibration Boards

Post by Micr0 » 21 Jun 2018, 19:14

martan wrote:
21 Jun 2018, 16:39
Again,

Received the original HP-panels today. First try att the 120mm scale.
The 6 big circles seems much bigger than the prinouts, Is this a factor in getting these (see picture)
error values?
Those look like very good numbers. Let us know if that makes a difference. Please post some pictures of your alignments with the new calibrations if you get the chance.
µ

3dxcan
Posts: 74
Joined: 02 Jun 2017, 17:21

Re: Calibration Boards

Post by 3dxcan » 21 Jun 2018, 20:28

Hp original calibration panel is made of glass or aluminum? I'm wondering how they are printing the dots on the panels accurately too.

martan
Posts: 54
Joined: 23 May 2018, 19:18
Location: Sweden

Re: Calibration Boards

Post by martan » 25 Jun 2018, 17:50

Quite sloppy setup today.

Calibration 120 mm on HP original calibration panel.
Random plastic thing painted with white PlastiDip.

DIY rotary table, 20 scans, 18 degrees. AutoIt-script.
Credit: https://sites.google.com/site/janbeck/3 ... for-david5

Settings, RMS and algnment according to pictures. "Orientation" set to "both"

(Acer P1265 and 2x TIS23UX236 with Computar 12mm MP "Old")
Attachments
before_alignment.JPG
after_alignment.JPG
settings.JPG
after_fusion.JPG
RMS1.JPG
RMS2.JPG
HP 3D Scan, Optoma ML750, 2x IS DMK 23UX236 with Computar 12mm, HP calibration panel, DIY Rotary tables.

mading
Posts: 130
Joined: 31 Jan 2017, 13:09

Re: Calibration Boards

Post by mading » 26 Jun 2018, 06:34

Thanks for the AutoIt script Martan.
A very nice tools for small objects (or huge turntables :-) ).
I have a question regarding calibration boards: Can you please make a scan of your panels and look for planarity with Geomagic or other sw?
I have the same cameras and the Acer 132 (non-david) and I still have errors of planarity more than 0.2 mm between two different scan of the same panel.
HP 3D scan, Acer K132, LG PF50, 2x DMK23UX236, 2xComputar M1214, David Calibration panels, Melamine panels, DIY rotary table

martan
Posts: 54
Joined: 23 May 2018, 19:18
Location: Sweden

Re: Calibration Boards

Post by martan » 02 Jul 2018, 16:17

Quick test today with homemade panel. Milled angles, 3mm glass and just office paper in the laser printer.
I enlarged the 3 circles a bit and this acually decreased the RMS Error to the 0,28-range (from 0,33-0,35)

100mm scale. Then I tried to decrease distance a bit and the error increases with shorter distance (greater camera/proj-angle).

20 scans, RMS in the 0,35-range on the office paper panel. I find tha original HP-panel bulky and it would be nice to have a smaller
hommade panel. Hopefully it will work out in the end. Comments? Good/bad?
Attachments
belzer_fusion.JPG
Fusion, Res 3000, Sharpness 0
belzer_scans.JPG
20 scans, 18 degrees, Stereo
100mm_cal.JPG
Calibration pattern, bigger circles
HP 3D Scan, Optoma ML750, 2x IS DMK 23UX236 with Computar 12mm, HP calibration panel, DIY Rotary tables.

mading
Posts: 130
Joined: 31 Jan 2017, 13:09

Re: Calibration Boards

Post by mading » 02 Jul 2018, 19:19

Hi there!
Nice results Martan!
My "woody" 160 panel, printed in a shop with a panel printer.
RMS 0.12-0.29 (why? maybe not properly focused..)
Set-up is vertical-horizontal, now I got better surfaces without waves! Thanks to BigBomber.

-> Setup is 'inner corner'
- RMS error is ok: 0.296544[..]
Horizontal open angle: 25.0155
Vertical open angle: 15.6929
-> Setup is 'inner corner'
- RMS error is ok: 0.127285[..]
Horizontal open angle: 24.9592
Vertical open angle: 15.7101
Angle between calibration panels: 90 degree
Optimizing Multi-Camera Calibration...
Calibrate Projector.
Angle between calibration panels: 90 degree
Size of camera's center pixel at background plane: 0.2536 mm

It's a fast try, with projector just sitting on a wood platform. Not even fastened to it.
Even in this situation I got better surface quality.

Comparison between two stereo scans at 0.08 mm:
2018-07-02_20-57-43.png
Two test scans (one flipped 180° to the others):
2018-07-02_21-01-45.png
Panels:
2018-07-02_20-50-07.png
2018-07-02_20-50-09.png
HP 3D scan, Acer K132, LG PF50, 2x DMK23UX236, 2xComputar M1214, David Calibration panels, Melamine panels, DIY rotary table

User avatar
Micr0
Posts: 393
Joined: 15 Nov 2016, 15:20

Re: Calibration Boards

Post by Micr0 » 02 Jul 2018, 21:48

are you using 2 cameras? One over the projector one under?
mading wrote:
02 Jul 2018, 19:19
Hi there!
Nice results Martan!
My "woody" 160 panel, printed in a shop with a panel printer.
RMS 0.12-0.29 (why? maybe not properly focused..)
Set-up is vertical-horizontal, now I got better surfaces without waves! Thanks to BigBomber.

-> Setup is 'inner corner'
- RMS error is ok: 0.296544[..]
Horizontal open angle: 25.0155
Vertical open angle: 15.6929
-> Setup is 'inner corner'
- RMS error is ok: 0.127285[..]
Horizontal open angle: 24.9592
Vertical open angle: 15.7101
Angle between calibration panels: 90 degree
Optimizing Multi-Camera Calibration...
Calibrate Projector.
Angle between calibration panels: 90 degree
Size of camera's center pixel at background plane: 0.2536 mm

It's a fast try, with projector just sitting on a wood platform. Not even fastened to it.
Even in this situation I got better surface quality.

Comparison between two stereo scans at 0.08 mm:
2018-07-02_20-57-43.png

Two test scans (one flipped 180° to the others):
2018-07-02_21-01-45.png

Panels:
2018-07-02_20-50-07.png
2018-07-02_20-50-09.png
µ

martan
Posts: 54
Joined: 23 May 2018, 19:18
Location: Sweden

Re: Calibration Boards

Post by martan » 03 Jul 2018, 04:19

Mading,

What happens if you turn the panel just a little clockwise?
Looks like that panel picture #2 is the camera with higher RMS Error. Correct?


M
HP 3D Scan, Optoma ML750, 2x IS DMK 23UX236 with Computar 12mm, HP calibration panel, DIY Rotary tables.

mading
Posts: 130
Joined: 31 Jan 2017, 13:09

Re: Calibration Boards

Post by mading » 03 Jul 2018, 05:51

Both cameras under the projector.
Sorry I had to move everything from my bench, so I'll try to check which is which (cameras).

I would like to make a gig for tilting the projector according to panel size, in order to use it with smaller panels (120-60).
Actually in the horizontal setup I'm limited to the 60 panels, due to K132 lens position.
It would be nice to make stereo at 30.. I still have to try the mod for the focus lever (courtesy of Avogra).
Attachments
IMG_20180702_210816.jpg
HP 3D scan, Acer K132, LG PF50, 2x DMK23UX236, 2xComputar M1214, David Calibration panels, Melamine panels, DIY rotary table

Post Reply