3D Samples: Photo Studio setup

This is the setup that I use:

• Compact camera (Sony DSC-WX350) mounted on tripod

• Remote control to shoot the camera via smartphone

• Ring light

• Rotary base (from Ikea) with marks every 15º

• Black foam to mask the base and the background

The main setup for the camera are:

• manual controls (Program Auto)

• highest image format (18M) and quality (Fine)

• lowest ISO (80)

• no flash

• manual white balance

• whole area focus and exposure

• other automatic controls disabled

I place the sample over the table and I start rotating it manually, shooting a picture every 15 degrees of rotation.

 I take a full ring of pictures with the camera inclined 45º, then a second ring with the camera inclined 10º.

I turn the sample upside down and I repeat the whole process.

The image shows the distribution and orientation of the pictures taken around the object. In this case a fifth ring of pictures was necessary with the camera inclined 0º, to allow the software link the pictures taken above and below the sample (this fifth ring is not displayed for clarity).

In total, 120 pictures were taken (five rings of 24 pictures each).

Then I process the pictures with a specific software for photogrammetry (Agisoft Metashape).

The most critical part is the pictures alignment that is successful when there are enough pictures with enough overlap so that the software can identify their similarities and position them in their proper location in space. In this case I had to add the fifth ring of pictures at 0º to succeed with this step and obtain the display of the previous image.

After this step, the other ones come in sequence, so I obtain the point cloud and finally the mesh and the texture that make up the 3D model.