camera makes noise while shutter is locked up in 30 second exposure

[MichaelBarry]

I was taking some long exposure shots with my sony A200 and kit lens. I selected the 30 second exposure time in shutter priority and while the shutter was locked up, i heard the camera making a sort of mechanical hissing (maybe from some sort of motor?) noise.

is this normal as I cannot imagine anything moving inside the camera to make this noise?

 

[a350]

I am unable to reproduce any noise on the a350. Does happen every time?

 

[MichaelBarry]

yes. It is very Very quiet and happens all the time.

I'm wandering if keeping the shutter open involves a motor of some sort to be active all the while the shutter is open?

 

[al256]

Could it be some sort of image stabilization/ vibration reduction activating in the middle of the shot?

 

[leighonigar]

Could maybe be the VR as suggested, or it could be a little solenoid or something making a bit of a buzz.

 

[TheReef]

I'd say it's the sensor moving around, I hear a similar sound on my K10D.

 

[a350]

I did a 30 second with the IS off and camera is silent with IS on camera was making all kinds of noise, with ear to camera.
If you are on a tripod shooting turn off IS. It will look for movement if there is none and actually create some.

 

[TheReef]

^^Yes turn it off it will make the images more blurry if you leave it on using a tripod.

 

[HBOC]

that is really crazy. I would never have thought something that is is helpful can work against you! Is the IS in body? I am assuming as someone pointed out that the sensor moves...