Shutter wear and EFSC

[banania]

I am a bit concerned about shutter wear as I would like to do some heavy stacking. I am using Canon 5D Mark II and was wondering whether EFSC/silent mode 1 or 2 has some bearing on shutter wear.

The 100K shutter actuations that Canon has "promised" for 5D Mark II, is very little. Does anyone know if this number relates to normal full shutter use or could it be that using EFSC would yield less wear for shutter and prolong this way the life of the shutter mechanism?

Also does anyone have any knowledge about the realism of the 100K number. My count for shutter actuations for the day is already over 2k and it is not even noon yet...

Henri

[rjlittlefield]

http://www.olegkikin.com/shutterlife/ca ... 5dmkii.htm reports "Average number of actuations after which shutter died: 232,446.6"

I would not expect different modes to have much effect on shutter life. As far as I know the sequence of shutter operations is the same in all modes; only the timing is different.

--Rik

[banania]

Thanks again Rik.

I must say that this is confusing for me as I don't really understand the exposure sequence in my camera and all kinds of explanations of EFSC can be found in the NET.

I figured that normally there is a mechanical first curtain moving down to open the sensor for exposure and a second curtain following and ending the exposure.

I vaguely remember reading something about simulating the mechanical first curtain with top-down line by line resetting of the sensor, exposure time being then the difference in time between this resetting and closing by the second shutter curtain. This simulated first curtain would make it possible to leave the mechanical FSC down while shooting in LiveView with EFSC ON?

BUT I wouldn't be a bit surprised to find out that I am just confused and making things up.

Here is a quote about EFSC... does this make sense?

"First a little explanation. Regardless of the camera, at high speeds, a mechanical shutter never fully exposes the sensor. On the 5D Mark II, in order to get a fast exposure above 1/200 second (the X-sync on the 5D Mark II), the second curtain has to follow right behind the first, creating a slit that moves across the sensor. Well, it turns out that the 5D Mark II's sensor can simulate the first part of this mechanical slit by starting to scanning the pixels in a line from top to bottom. Then the second curtain does have to come into play to close off the slit and finish the exposure. That means you can open both mirror and shutter once to enter Live View mode, then fire off 3.8 frames with only the sound of the second shutter, because the mirror and first curtain don't move.

Mode 1 is quite fast, with less noise and vibration, both because the mirror's not flapping around (it's locked up in Live View mode, and because of the electronic first curtain trick. "

http://www.imaging-resource.com/PRODS/E5D2/E5D2A5.HTM

Sorry to bother you with this, hope you don't mind...

Henri

[Pau]

Here is a quote about EFSC... does this make sense?

...then fire off 3.8 frames with only the sound of the second shutter, because the mirror and first curtain don't move.

Not fully.
The first mechanical curtain also moves but to restart LV after the actual exposure, not to beguin the exposure that is iniciated by the electronic first curtain and finished closing the second mechanical curtain.

With electronic flash the sequence is different: close the shutter, open the first curtain, fire the flash, close the second curtain and open the first curtain to restart LV. This is done to provide the flash sync signal and BTW is not quiter than without LV with mirror lock up.

[rjlittlefield]

This simulated first curtain would make it possible to leave the mechanical FSC down while shooting in LiveView with EFSC ON?

It would be possible to design a camera that works like that, but I've always thought that the operation is like Pau describes.

In normal mode the shutter action is

• long pause while framing and focusing
• mechanical first curtain
• exposure delay
• mechanical second curtain
• reset both curtains

In EFSC mode it is

• mechanical first curtain
• long pause while Live View
• EFSC clears sensor
• exposure delay
• mechanical second curtain
• reset both curtains

You can probably confirm all this by just removing your lens, setting a couple of seconds' exposure time, then looking into the front of the camera while running it through its paces.

--Rik