Originally posted by Lowell Goudge Actually it does also happen with a mechanical shutter. Unless you have an iris shutter a vertically travelling shutter is no different than a rolling shutter.
Well, not quite true -- with mechanical shutter all lines on the sensor are exposed at once, or at least within that 1/2000s, whereas with electronic shutter it always takes 1/13s to get through all the lines. The difference is that with mechanical shutter it downloads the data off the sensor after whole sensor has been exposed while with electronic shutter it "exposes" a row for 1/2000s, downloads the data for just that row, moves onto the next row, etc. This is the bottleneck that causes the 1/13s thing.
In any case I've never seen the effect on a still image with a mechanical shutter and using those kinds of lights was my standard for ebay shots (of which I do a alot) for a long time (I use flash now). I did see it on the screen, but never in the images themselves. It is possible maybe with certain shutter speeds? But I've not seen it...