Fujifilm X-H2S Electronic Shutter Photographic Dynamic Range (PDR)

Jerry-astro wrote:

Alan Sh wrote:

bclaff wrote:

a_c_skinner wrote:

What is the reason? For the simple person?

Electronic Shutter (ES) read out has higher read noise than Mechanical Shutter (MS).

I must be missing something. I thought ES was just MS without the M - so the mechanical bit just isn't there.

What am I missing? Is there something I can read that explains the actuall mechanisms of ES & MS?

ALan

Decent explanation by Fujifilm here:

https://fujifilm-x.com/en-gb/learning-centre/electronic-vs-mechanical-shutter/

Bottom line, as I understand it, there remain situations (most often relating to motion photography) where the differences between the two can become very apparent. It's my understanding that motion related artifacts attributable to ES still exist, even in the latest generation ES implementations. I'm more than happy to stand corrected if there is updated data that suggests otherwise with newer gen cameras. A reference to such information -- if it exists -- might be very helpful in answering the questions being raised here.

Meanwhile, out of an abundance of caution, and until I see data to the contrary, I will continue to avoid using ES in any situation where motion is involved.

Focal plane mechanical shutters are rolling shutter just as ES are. In lens leaf shutters do not suffer from rolling shutter. The focal plane mechanical shutter travels as a slit between the two curtains across the sensor. The transit time of the slit is about the same as the flash sync time or more or less 1/250. At faster the shutter speeds the smaller the slit which means it exposes the top part of the sensor prior to the bottom part and that is what leads to rolling shutter.

At 1/1000 for example only the slit is on the order of 1/4 of the top to bottom distance of the shutter so the bottom of the sensor is exposed prior to the top. At high shutter speeds the mechanical shutter will show the effects of rolling shutter - bent baseball bats. bent golf clubs, etc. When the flash sync speeds of the ES and MS are equivalent - there will be no advantage related to rolling shutter with one vs. the other. That is what Nikon based the Z9 design on.

https://www.youtube.com/watch?v=CmjeCchGRQo

It may very well be that the stacked sensor in the XH2S, Fuji could followed in Nikon's lead and removed the mechanical shutter.  One would have to look at the read out rates to determine that, but I expect both those sensors are from the same generation of the Sony sensor technology.  At one point the read noise penalty from rolling shutter made ES a less attractive.  However, with the modern sensors, the noise temperature of the CMOS circuitry makes this penalty insignificant and only an issue at close to base ISO.