Just today I replaced Arducam ov5647 camera with a real v1 camera (clone) for taking global shutter images.
For adjustment I took some images of rotating propeller (20000rpm) showing strange rolling shutter effect with raspistill and a 1000lm only unfocused Ikea lamp. From left to right, top to bottom with 25/50/100/200/400/800µs shutter time. For 25/50 I had to increase brightness from 50 to 75 (-br 75) in order to see something:
Then I used focused 5000lm bright light and as you can see 25µs shutter time is good enough to get a clear picture (of eg. the non-moving motor):
Shutter time is always a multiple of line_time_ns (which is 21165ns for v1 mode 7). Because of integer division therefore real shutter time for the image taken is not 25µs but 21.165µs.