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.
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.
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.
The success of the 90 degree lens on the Firefly 8S and 7S meant that I started to look for other cameras that are also sold with narrower angle lenses. While the firefly “non-distortion” versions seem to be quite popular, and so suggest that this may become a more common option, at this point almost all action cameras have 170º lenses.
The Gitup Git2p also has a 90 degree version, but this camera is the same price as the Firefly 8S and still only has the Novatek 96660 chip, so isn’t capable of native 4k. While it does use the Panasonic MN34120PA sensor (which is reputed to perform well in low light), the newer model (GitUp G3 Duo) now uses the Sony IMX117 sensor, as used in the Firefly 8S.
At the time of writing, there do not appear to be any other “non-distortion” action cameras on the market.
The success of the Firefly 8S with 90º lens led me to purchase the earlier version, the 90º Firefly 7S. This camera has the common Novatek 96660 chip (not capable of native 4K) and Sony IMX078 sensor.
Like the Firefly 8S, the lens was very easy to release from its fixed focus. However, the main downside of this camera is that the app (iOS and android versions) does not support the full recording options – it does not allow time-lapse recording, and only allows real-time recording at HD (not the higher resolutions that are available via the on-screen controls. Continue reading →