Gene51 Loc: Yonkers, NY, now in LSD (LowerSlowerDelaware)

You are correct - shutter vibrations when coupled with inadequate tripod/head are the principal cause of blurred images when shot between 1/10 and 1/160 sec.

Mirrorless cameras are just as susceptible - read the various posts about the Sony A7R and others.

http://www.sonyalpharumors.com/the-shutter-vibration-issue-explained-by-joseph-holmes/

Unless your camera has an electronic front curtain, shutter movement can affect an image.

The best prevention is to get the right tripod. Forget about shutter delay, remote shutter release, mirror lock up - etc etc etc. No substitute for a solid platform. Period.

anotherview Loc: California

Good question. Part of the answer lies in the results from applying the Camera Shake Reduction filter in Photoshop Creative Cloud. The loupe in CSR presents a before-and-after view. The before-view shows some minute blurring even in an image done at a higher shutter speed.

I own and use the Fujifilm X-E2, a mirrorless camera, and its images show this blur, too.

I presume the inner workings of the camera produce a vibration that induces this blur.

Whatever, CSR evidently returns the image to a sharpness reflecting the native optics of a lens. Few of my images need any additional sharpening now.