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E-Shutter readout speed/rolling shutter

Started 6 months ago | Discussions thread
Dem Bell Senior Member • Posts: 1,091
Re: E-Shutter readout speed/rolling shutter

nnowak wrote:

Alan Hewitt Photo wrote:

I'm about as technical as a old bit of wood so there's a good chance I'm wrong on this! But... I would imagine some machine or software that is capable of accurately timing electronic shutters charge and read out like this to thousandth of a second would be so incredibly niche and specialist it's probably out of reach of review sites, even the mighty DPReview!

There is no need for anything that complicated. One of the simplest methods uses standard household LED lights. Some (many?) of these lights will flicker at a rate that is double the mains frequency. If you use E-shutter to photograph a light colored wall illuminated by one of these flickering LEDs, your photograph will have regularly alternating light and dark bands. If you know the flicker frequency of the LEDs and count the number of bands, it is simple math to calculate the readout speed.

It is much more accurate to measure the distance between bands in pixels, N. If you are in Europe, this distance corresponds to 10ms. If you divide image height H by N, then multiply the result by 10, you'll get the sensor readout time in ms.

This method won't give you an answer down to the last decimal place,

Should be able to get within 1%.

but it will easily distinguish between 1/30 and 1/60.

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