Snow Train – work in progress

I have been working with a 7 minute piece of footage shot during the March 2018 snow, from the train window between Wimbledon and Clapham Junction stations, passing through Earlsfield. The footage was compelling largely due to the transformation of the city, both green spaces and built-up areas, by the layer of snow.

I started with the simple triptych format that I had employed in “Approach“, staggering the single vertical format section of footage by just under a second – this was enough to align the objects at a relatively close distance. I used the “Wimbledon A” signal box in the shot below as the register for the time separation. Objects closer and further from the camera are out of alignment between each frame, due to the differential parallax.

I left the sound from the recording (from the carriage from which I filmed), which created an interesting trebling due to the small time offset. Continue reading

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.

Click to access 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