Electronic shutter: advantages and disadvantages

tt321 wrote:

Jacques Cornell wrote:

Helen wrote:

Raist3d wrote:

Henry Richardson wrote:

Raist3d wrote:

Henry Richardson wrote:

I discovered today that Auto ISO is broken when using the electronic shutter. I am using A mode.

electronic shutter: @ 150mm - ISO 200, 1/30 f5.6

mechanical shutter: @ 150mm - ISO 2000, 1/250 f5.6

I have been using Auto ISO a lot since I got the E-M5 in 2012. Use it on the E-M5, E-M10, and E-M10II. But, now with the electronic shutter there is a bug.

This is not a bug. What I believe Olympus is trying to avoid is banding in the shot in low light conditions.

Would you mind elaborating? I thought banding was just with fluorescent, LED, etc. lighting.

Of course, the camera can't know, but I was outside late in the afternoon.

What I am saying is that Olympus is most likely trying to avoid situations where the camera would do banding due to one of those lights that has a frequency. The camera can't just guess exactly the type of light particularly in a mixed situation, so I think in general they just try to make sure banding can't ever happen by keeping the shutter speed slow in program-auto modes.

Using a slow shutter speed does not eliminate banding.

It does if the shutter speed is not higher than the full frame scan speed. So it might make sense not to rush to raise shutter speeds with higher ISO beyond this speed.

When do you stop raising the ISO? In one case after you've exceeded the safe hand holding speed (related to the FL of the lens) - makes sense for the mechanical shutter. In the second case after you've exceeded the electronic full frame scan speed - could make sense for the electronic shutter if avoiding e-shutter artefacts is regarded as more important than hand-shake.

Artefacts can become observable when the shutter speed is higher than the scan speed.

Good points. We're talking now, though, about shutter speeds slower than 1/25, 1/15 or 1/10, depending on sensor, and these speeds are pretty borderline in terms of getting a sharp shot handheld with longer focal lengths, even with static subjects, IS notwithstanding. So, it's hard to see how camera engineers would come to the conclusion that AE modes should risk motion blur under every kind of light just to avoid banding under some kinds of light. I can see how this might be the thinking, so Raist3d's is more plausible than I initially thought. But, if this is the explanation, I really have to question the engineers' judgement.

Apologies to Raist3d for dismissing the idea prematurely.