How to adjust image circle position on the center?


After using camera+lens set which uses modified GoPro kit’s Back-Bone Ribcage for some time, you might start noticing some problems. In case you have the problem of stitching not going well, or any other problems, you should check whether the position of image circle is right or not.

Normally the image circle should be in the center of the screen. However, something some part of lens shifts out of its position or something else happens and the image circle gets dislocated from the center.

In some cases, the slippage is so small that it doesn’t cause any problems but sometimes it leads to problems in stitching.

Problems that occur if the image circle isn’t in the right place.

Stitching doesn’t go well

If the image circle is out of place, image circle cannot be correctly recognized by VR software Autopano Video. As a result, stitching won’t go well.

Not being able to stitch

In case you are shooting in 4K mode Back to Back with Entaniya Fisheye 280° and the position of image circle is out of place, the image joints will be badly combined and in the worst case, you won’t be able to create 360° VR footage.

How to confirm the right position of image circle.

Confirming by picture mode with connecting to monitor with HDMI.

Connect GoPro and monitor with HDMI cable to confirm the position of image circle.

If using picture mode, everything will be displayed in aspect ratio 4:3. This is why you need to change to picture mode.

Right position of image circle.

Entaniya Fisheye M12 220

Entaniya Fisheye M12 250

Entaniya Fisheye M12 280

The method of correctly adjusting the position of image circle.

Above shows an example of focus being out of the center of image circle.
The image circle is out of position in upward direction.

This problem occurs because the lens holder of Back-Bone Ribcage slips out of its place.

Tightening the screws while holding the platform of lens.

In case you wish to move the image circle down, you can fix the image circle by pushing the platform up. In case you need to move the circle up, you should be able to fix it by pushing the platform down.

In short, it can be fixed by moving the platform to the opposite direction of where you want to fix the image circle.

Installing a lens and confirming that the position of image circle is right

Install a lens to the camera and confirm that the image circle is right.
We were able to fix the image circle to the center.