In another forum the following image of a X-T1 at 1/32000 has appeared. High electronic speeds such as 1/32000 are fine for exposure, but not so much to freeze moving objects because of the rolling shutter effect derived:
If the entire sensor is read in 1/32000th of a second, one line at a time, having 3264 lines, that means 1/10th of a second to read the entire sensor, pretty slow. But I have made some calculations (subject to several assumptions) and the result has been around 1/30th.
Does anyone know the real time it takes to read the entire sensor in the X-T1 working at 1/32000?
I did the following:
- Assumption 1: arrow diameter 8mm. This coincides with 8px in the original 1280px wide image.
- Ratio between arrow speed/sensor readout speed: 60:133
- Assumption 2: arrow speed 200 Km/h
- 200 Km/h = 55.556 mm/s. Since in the image 1px~1mm the arrow flies horizonally at 55.556 px/s
- That speed translates (60:133) as 25.063 px/s vertical readout
- Assumption 3: the original 3:2 image was cropped up and/or down, I added lines to complete 853 px height (the image was 1.280 width).
- 853px at 25.063 px/s requires 0,034s -> vertical readout speed = 1/30th of a second
What do you think? 1/10th? 1/30th?
Regards