Re: Silent Shutter = flicker if over 1/60

[ectobuilder]

Re: Silent Shutter = flicker if over 1/60

I'm noticing that the Silent Shutter is producing flicker with interior lighting at anything above 1/60 (in my kitchen anyways). But when I use the regular shutter it is ok.

Anyone else experiencing this problem?

Another problem is that the flicker is not noticed until AFTER you review the shot. Live View does not show this.

 

[Mattoid]

This is just a scientific fact caused by a rolling shutter with a scan time of about 30 milliseconds. The image is captured throughout this time regardless of shutter speed. Lights flash on and off in a continuous sine wave pattern at either 100 or 120 times a second (depending on the mains frequency). If you are in america the frequency is 60hz, so 60 complete oscillations, so 120 on and offs. 1/120th of a second is 8.33 milliseconds. Which means the lights flash on and of about 3 and a half times during the scan time.
Like a cross sectional sample of the earth: The image reveals the actual light in the room at a particular time during the 30 milliseconds.

The reason that this doesn't happen at lower shutter speeds is because the sensor has to make multiple passes. So in the next pass at a particular point on the sensor, the lights will probably be at a different point in their cycle, combined exposure is averaged out somewhat.
What this does create instead is ghosting if the subjects move. Whereas a normal long exposure has motion blur, a rolling shutter exposure has layers of ghosts on top of each other approximating motion blur.

As for why live view doesn't show this: live view probably line skips making the scan time more instantaneous.


Banding was a complaint a few months ago when people tried the electronic shutter on the Panasonic GM1. The only way around it is to use constant or 3 phase lighting, or daylight. Or just use the physical shutter.