om-d sound even when IBIS off??

Started Apr 16, 2013 | Discussions thread
Anders W
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Re: om-d sound even when IBIS off??
In reply to JohnBGood, Apr 18, 2013

JohnBGood wrote:

Anders W wrote:

JohnBGood wrote:

Eugg1 wrote:

Hi all,

When I take a long exposure picture, I still hear a fanning sound from my om-d, even when I turn off the ibis.
Is this normal?
Any reactions are appreciated.

Thanks!

Have you updated your firmware to the latest version?

Since the last update, if I want to hear the "fanning sound" I have to place my ear against the viewfinder, if not I don't even hear it in a normal environment.

Note that the OP is talking about long exposures. During exposure, you'd still hear the "fanning" sound no matter which firmware you are running. For short exposures, you obviously won't notice it but for longer ones you will.

Thanks for the info Anders,
Never noticed it before, so being the skeptic that I am, I tested it and of course you are right!
So I guess I'm to absorbed by the composition process when shooting long exposures or I'm going deaf!

Thanks again

You are welcome John. A bit of scepticism is a good thing if combined with the ability to observe and accept clear evidence.

For those interested, here is a summary of the ins and outs of the sound produced by the E-M5 IBIS system:

First, the IBIS system is in some ways operative whenever the camera is on. With the camera on, the sensor is held in place by electromagnetic force. When the camera is turned off or enters sleep mode, the sensor falls down to the bottom of the space reserved for it. If you look at the naked sensor, you can easily see it move up and down as you turn the camera on or off.

In some cases, IBIS operates in what might be called low-power mode. This produces a sound that is barely audible. You need to put your ear rather close to the camera to hear it. In other cases, the camera switches to high-power mode. This produces a clearly audible "fanning" sound.

With the first firmware releases, the low-power mode was used for video only. In other cases, the camera switched to high-power mode, thus producing the clearly audible "fanning" sound most of the time. From firmware 1.5, however, the low-power mode is used most of the time and the camera switches to high-power mode only in some special but important cases as detailed below. This has the benefit not only of making the operation more quiet but also of saving battery power.

In low-power mode, the sensor is held gently in place in a manner sufficient for live view. If you are shooting video and IBIS is on, the sensor is additionally moved gently around to counteract camera shake. The reason why low-power mode is sufficient for video is that the primary objective in this case is not to make each individual frame as sharp as possible. Rather, the point is to reduce jerkiness across frames and smoothen changes in framing due to camera shake. For this purpose, the sensor rarely has to move at max speed.

From firmware 1.5, high-power mode is used in two cases only: 1) during stills exposure and 2) when IBIS is on, the "Half Way Rls With IS" in the "Release" section of the "Custom Menu" is on, and the shutter button pressed half way. In high-power mode, the sensor is "hugged" so as to be kept rigidly in place. If IBIS is on, it is also moved, at maximal speed if required, so as to counteract camera shake.

In conclusion, I offer two simple experiments that sceptics might want to undertake in order to test some of what is said above. These experiments presume that the camera is using firmware 1.5 or later.

Experiment 1: Set a long exposure time (e.g., five seconds) and make sure IBIS is turned off. Place the camera on a table or a tripod so that it does not move during the exposure. Note how the sound increases to the clearly audible "fanning" sound during the exposure. Repeat the experiment with IBIS turned on. Again, you will hear the same kind of clearly audible "fanning" sound during the exposure.

Experiment 2: Repeat experiment 1 but with the camera held in your hands rather than resting on a table or tripod. Move the camera around a bit during the exposure. If you have lens with long focal length mounted, you need to move it just a little bit. If you have a lens with short focal length on the camera, you might want to move it a little more. The sound during exposure with IBIS off will in this case be very similar to what you heard in experiment 1. With IBIS turned on, however, the sound will be equally loud but more irregular due to the fact that in this case the system is not only holding the sensor rigidly in place but also moving it around in an attempt to counteract your movements.

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