Lens image circle size

Further research on camera lenses and image quality indicated that another detail of the lens specification was relevant –  the “lens image circle” needs to be slightly larger than the sensor diagonal to avoid dark corners in the image.
http://www.optics-online.com/doc/files/Application%20Note%20Image%20Circle%20Tolerance%20copy.pdf

I am therefore noting the sensor size in my Action Camera Comparison Chart, to ensure that any new lens has a sufficient image circle for the sensor.

M12 Lenses

As the options for cameras with non-wide angle lenses is very limited, and as the lenses on the action cameras are completely removable once they have been released from their fixed focus, I decided to look for replacement lenses, rather than entire cameras with narrower fields of view. The lenses for action cameras, FPV drone cameras, and many CCTV cameras generally use the M12 thread size.

Continue reading

Quelima SQ11

The Quelima SQ11 is a very small, low resolution and exceptionally cheap camera, with IR LEDs for night shooting. I bought the camera to test the quality of image from such a small camera as it may allow filming in smaller models.

While the camera is marketed as 1080P HD, it is only capable of native 720P resolution. It has a Generalplus 1248 processor and a very small and unspecified CMOS sensor.

Continue reading