E-P5 and "shtter Shock"

Started 10 months ago | Discussions thread
Anders W
Forum ProPosts: 17,343Gear list
Like?
Re: Shock vs. shake
In reply to Andy Westlake, 10 months ago

Andy Westlake wrote:

Anders W wrote:

You claim that placing the camera on a tripod should not reduce the blur if it were indeed due to shutter shock. Could you please explain in physical terms why you think so.

I expect 'shutter shock' to behave in practical terms like mirror slap - the vibrations from the shutter would be transmitted largely internally. Mirror slap can sometimes be reduced on a tripod, but in my experience (from countless hours testing cameras and lenses as my day job) it never goes away entirely. I once tried to test a 1.5kg Sony 70-200mm F2.8 bolted down hard onto to 6kg Manfrotto 058 with an NM405 geared head, using an SLR without mirror lockup. Nothing I tried would make mirror slap go away.

Have you seen this test, probably the most serious investigation of shutter shock ever conducted:

http://www.falklumo.com/lumolabs/articles/k7shutter/index.html

See especially section 4.2 where there is a test specifically for vibration. The conclusion is negative. It's a matter of extraneous movement, not vibration.

The test I reported in my post here (to which you already responded) also rules out vibration as the cause. Placing the camera on a concrete floor prevents it from moving but not from vibrating. Nevertheless, there is no blur in this case.

http://www.dpreview.com/forums/post/52289880

The outcome you describe here is indeed mysterious. But if you have problems with unexpected blur even with two-second self-timer or anti-shock, that shows conclusively that the problem is not due to the mechanism you first pointed to in your E-P5 review (the shutter button and the way it is pressed), no?

No. It just shows that if you wait two seconds for a shutter release after pressing the button, the shakes return. It doesn't tell you why, and it tells you nothing about what happened 2 seconds before. For the record I've never, with any camera, found a 2 second delay to be helpful at reducing shake hand-held - generally the opposite.

My claim was only that a two-second delay rules out the possibility that the problem is due to shake caused by the shutter button and the way it is pressed. Are you saying that you expect shake due to button pressing even after two seconds?

A few things to keep in mind here:

First, in my experience/testing, the extent to which anti-shock helps at all is strongly dependent on how you hold the camera. If you hold it right (from a shutter-shock prevention point of view), anti-shock will not be of much additional help. If you hold it wrong, it will.

That sounds to me like an excellent descriptor of something that's highly influenced by camera shake, which logically is highly influenced by how you hold a camera.

Are you somehow trying to insinuate that what I said is tautological?

The shutter causes a shock. The consequences of that shock for image blur depends on how you hold the camera. If you hold it the wrong way the consequences will be worse than if you hold it the right way. Similarly, the impact of the anti-shock delay varies with the way you hold the camera. If you hold it right, anti-shock will be less helpful than if you hold it wrong (simply because there will be less of a problem for anti-shock to take care of). Do you follow my description and its logic? And do you see anything wrong with it?

Note that holding the camera in the way that is conventionally regarded as optimal in order to prevent ordinary camera shake (supporting under the lens with your left hand, using head support) has been shown not to be optimal in order to limit the impact of shutter shock.

Again, see this post/thread for a discussion of the issues involved:

http://www.dpreview.com/forums/thread/3496076

As to the E-P5 specifically, note also that it has another shutter than previous Oly MFT cameras. Since the new shutter allows flash sync at a faster speed (1/320 rather than 1/250), its blades must by definition move at a faster speed than on earlier shutters. Everything else equal, this is a drawback from a shutter-shock point of view since greater speed yields more momentum to be absorbed.

Of course, everything else is equal only if the E-P5's shutter is the same mass as the E-M5's, and we don't know anything about that.

Yes. That's why I said everything else equal.

Olympus also says the E-P5 has a reduced shutter lag compared to the E-M5, and it certainly has a less-soft feel to the shutter button.

As far as I can see, your own testing with a two-second delay has already ruled out the possibility that the "feel" of the shutter button has anything to do with it. You aren't seriously arguing that the shock due to button pressing (as opposed to the shutter action that press releases) can manifest itself two seconds after the fact, are you?

A reduced shutter lag shouldn't change anything with regard to shutter shock as long as it is the delay between button press and beginning of shutter action we are talking about. Possibly, changing the time between the first phase of shutter action (shutter closing to prepare for exposure) and subsequent phases might (this is the time addressed by the anti-shock setting), but I doubt that there has been much of a change in this regard or that it would have much of an effect.

The key point I'd really like to make, though, is that the specific shake issue we see with the E-P5 is not something we see in normal shooting with the E-M5. The two cameras behave differently, so whatever you've learned about the E-M5 may not apply.

I realize that this is your key point but wouldn't be so sure that you are right. While I certainly can't know for sure at this stage, my guess is that you will in the end find the root cause to be the same (shutter shock) although it may well manifest itself in slightly different ways. I look forward to your reply to the question about your comparative testing of the E-P5 and E-M5 that I asked in another post here:

http://www.dpreview.com/forums/post/52291888

 Anders W's gear list:Anders W's gear list
Panasonic Lumix DMC-G1 Olympus OM-D E-M5 Olympus E-M1 Panasonic Lumix G Vario 14-45mm F3.5-5.6 ASPH OIS Panasonic Lumix G Vario 7-14mm F4 ASPH +21 more
Reply   Reply with quote   Complain
Post (hide subjects)Posted by
Keyboard shortcuts:
FForum PPrevious NNext WNext unread UUpvote SSubscribe RReply QQuote BBookmark post MMy threads
Color scheme? Blue / Yellow