motion blur....

Have a look at this picture (which is a crop from a larger one) and the small crop to show what the problem is.
This was taken with a 5D2, 24-105 L @24mm, F22, T30' on a tripod with remote shutter control.

I cannot explain the blur other than that the building I was in (and still am) was moving/swaying.... I was on the 21st floor of a 22 story hotel in Surfers Paradise, QLD Australia.

Anyone ever experienced the same?

Did you have IS turned on or off? Ed Rader started a thread awhile back that's a good read: https://photography-on-the.net/forum/showthre​ad.php?t=695198

Also I'd think your images would be sharper at something like f/11 instead of f/22.

After a few drinks, this motion blur can happen. If your lens has IS and is mounted on a tripod, turn it off.

For that length of shutter speed you might want to try the mirror lock up setting. Should be in custom functions.

vk2gwk wrote in post #9064721
I was on the 21st floor of a 22 story hotel

Were you shooting through a window? I doubt the building was swaying that much. It is more likely that the IS was on and went into an open loop since the camera was mounted on a tripod.

jacuff wrote in post #9064858
Were you shooting through a window? I doubt the building was swaying that much. It is more likely that the IS was on and went into an open loop since the camera was mounted on a tripod.

My first thought too. Also what tripod were you using? - not all tripods are as stable as you might think. Also, if you have a grip attached to your camara they can cause blur as they tend to flex at the tripod mounting point more than camera body itself does.

Thanks all for the suggestions and advice. Yes... I should have thought about that myself as I had read the manual.... but not done what the manual told me to do: switch off the IS.
It certainly solved the problem and the hotel is not swaying (noticeably.... )
And, yes BobA - this F/11 at 15 sec and that one is sharper than the F/22 at 30 sec. I shot as well. I tried to work out why but haven't found that out yet. Can you explain? DOF at F/22 should be wider (start closer) and the most central (=best) part of the lens is used. So why should F/11 be better...???

This is the result....

vk2gwk wrote in post #9066014
DOF at F/22 should be wider (start closer) and the most central (=best) part of the lens is used. So why should F/11 be better...???

DOF is wider, but wider DOF doesn't always equal the sharpest at 100%. When the file is printed, it becomes less of an issue but still something you should be aware of. It is called Diffraction Limited Photography. Read more about it here: http://www.cambridgein​colour.com …ffraction-photography.htm

D Thompson wrote in post #9064843
For that length of shutter speed you might want to try the mirror lock up setting. Should be in custom functions.

I don't bother with MLU for such long exposures. With a decent tripod the vibrations from the mirror movement aren't going to last for anything like an appreciable percentage of the exposure time.

vk2gwk wrote in post #9066014
....this F/11 at 15 sec and that one is sharper than the F/22 at 30 sec.

Do you realize that f/11 at 15 seconds is not the same exposure as f/22 at 30 seconds? f/11 to f/22 is a two-stop change and 15 seconds to 30 seconds is only a 1 stop change. The exposures of the two images you've posted are not the same.

vk2gwk wrote in post #9066014
Can you explain? DOF at F/22 should be wider (start closer) and the most central (=best) part of the lens is used. So why should F/11 be better...

With digital cameras, there is a possible reduction in sharpness when using very small apertures. It's due to something called diffraction. I don't know enough about diffraction to describe what it is and why it takes place, but you could search for "diffraction" in these forums.

You did not reply to the question above about what tripod you are using. All tripods are definitely NOT alike, and you could have had some motion with one shot and not another merely because someone was walking around the room during one shot, causing vibrations which were amplified by a not-so-sturdy tripod. Also, with a 30-second exposure, you have twice the time for something to cause a vibration which could be picked up by the tripod as you do with a 15-second exposure.

Thanks to various posters for pointing out the diffraction issue. I read up on that and now understand it (I think).
And yes I know I changed the exposure. I also took one at the same exposure but one stop difference made it better.
The tripod is not a very heavy one (we are travelling...) but stable enough for this camera and lens combination.
I did not bother with mirror lock up for the reason Hollis_f mentioned.
Thanks all for the help and pointing out the diffraction. There are far more things I do not know about than there are things I know and that'll never change.

The effect you got is definitely motion blur, and definitely not diffraction. For diffraction to be that visible, you'd have needed an oval aperture of perhaps f/128.

F/22 on APS format will cause a slight softening. It's caused by an interference pattern of light waveforms around the edge of the aperture.

To your original question: Yes, buildings can and do sway in the wind. In this case, the lighted tower thing was also swaying, and seemingly to a greater extent than the building you were on. But those street lights look as though they smeared through a couple feet, which would require either a very slight twisting motion, or an exceedingly strong swaying motion. I don't think those trees would still be upright, so I'm going with the former, if building motion it is.

IS run amok could do this easily. So could a slight bump of the tripod halfway through the exposure.

Rick "who has had a bunch of very long exposures go awry for reasons unknown" Denney