Electronic First (Front) Curtain Shutter

[peterqd]

On the NEX-7 I have the option of using or not using EFCS. I believe this option is also on the A7 and some other cameras. The benefits of using it are:
- reduced time lag between shutter releases
- fewer shutter movements per shot (extending camera life)
- marginally less vibration

So why would I NOT want to use it?

The manual has two bullet points under the description of the function (page 134 in the GB version) which I find very confusing:

[calvin83]

You could find the 'answer' here: http://www.mhohner.de/newsitem2/efcs .

A short answer will be:
If EFC is enable, the camera is not reading the charge of all the pixels at the same time. Some of the pixels on the sensor will exposure to the light longer than the other pixels. This might create some ghosting/blurred area in the photo.

[memetph]

[peterqd]

Thanks Calvin. I couldn't find a plausible reason not to use EFCS in the link you gave me, but Michael Hohner made a
follow-up page which I found later. He says lenses which are non-telecentric (i.e. the light hits the sensor at varying angles, not
perpendicular) can cause differences in exposure times from one side of the frame to the other.

Memetph, many thanks for that. On my NEX-7 the increase in shutter noise happens at all speeds it seems to me - it's a double
motion compared to a single motion, as Mr Hohner describes in Calvin's link. I don't find the noise annoying at all, in fact it's more like
an SLR shutter sound, but of course the life expectancy of shutter actuations is halved.

Yes, you must be right - this applies to any non-E mount lens. I don't think any of my lenses are telecentric (except perhaps the
E-mount kit lens but I'm not sure about that and, anyway, I don't use it very much). I think I'll turn EFCS off and if I can see any
appreciable difference I'll report back.

[calvin83]

Take a look at this thread on FCS http://www.dpreview.com/forums/thread/3060853 . There is some insights which Michael might not covered.

[BurstMox]

I noticed (on A7) that with EFC, you can have problems when the shutter speed is pretty high (more than 1/2000), which will result in this type of vignetting :

http://forum.mflenses.com/nex-6-vignetting-on-one-side-of-image-t64622.html

I never had such problem with EFC "off".

[peterqd]

[peterqd]

[visualopsins]

Please excuse my ignorance -- does NEX have a mechanical shutter (wears out & fails) or electronic shutter (no wear)? Thanks in advance.

[peterqd]

All digital cameras have mechanical shutters as far as I'm aware. With DSLRs the shutter is normally closed, but because the NEX
cameras are live-view, the shutter has to be open for framing and focussing. So when you take a shot the shutter has to close first
before performing its normal operation and then open again afterwards. This effectively doubles the number of "actuations".

On the NEX-5n and 7, and some of the later bigger Sonys, there is an option in the menu to turn on electronic front (or first) curtain
shutter (EFCS). This wipes the image in the sensor electronically before the shot is taken, so the first actuation to close the shutter is not
required. This halves the number of shutter movements and causes a shorter and quieter shutter noise.

[calvin83]

There are many camera with electronic shutter. This includes some old Nikon cameras (D40/D70, D1 series and the Nikon 1), some of the Panasonic camera (G5/G6) and the Sony A7s etc. However, the banding problem might become more serious with a full electronic shutter.