[MarkJerling]

Hi,

I've been having problems recently with heavy motion blur appearing in shots where there really shouldn't be any. See the example below (full size: motion blur | Pieter Wouters | Flickr), taken at a reasonable focal length and shutter speed, but everything's blurry and if you zoom in on the man you can clearly see motion blur as if the camera was shaking up and down violently. The problem has been hard to reproduce since it seems to happen randomly, and often taking the same shot immediately after gives a satisfactory result. It only started quite recently but since then has occured in quite a few shots.

I've looked around a bit and some people seem to be experiencing the same problem, but I haven't found any conclusive answers as to why this is happening, or any solutions. My guess is that the shake reduction setting causes the sensor to move around far more than it should. I tried taking some shots with SR off and the problem was gone (but as I said, it appears randomly so this might have been a coincidence).

Has anyone had the same problem and found a solution for it?

Thanks for any information.

This photo shows a very distinct vertical motion blur. Are all the other images blurring in the same direction? Any chance you're moving the camera while taking the shot?

[stevebrot]

This photo shows a very distinct vertical motion blur. Are all the other images blurring in the same direction? Any chance you're moving the camera while taking the shot?

Even more than distinct, it presents as a puzzling vertical doubling is inconsistent within the frame. The full resolution version on Flickr is helpful.

All sizes | motion blur | Flickr - Photo Sharing!

Direct download : https://live.staticflickr.com/65535/46997118554_25609bfdaa_o_d.jpg

I am wondering if there is funny business happening within the lens, say something like the AF operating during the exposure or mechanical hysteresis or subtle shift in elements due to slight movement of focus or zoom rings when using a "left hand under the lens" hold. Are we sounding strange yet?


Steve

[MarkJerling]

Even more than distinct, it presents as a puzzling vertical doubling is inconsistent within the frame. The full resolution version on Flickr is helpful.

All sizes | motion blur | Flickr - Photo Sharing!

Direct download : https://live.staticflickr.com/65535/46997118554_25609bfdaa_o_d.jpg

I am wondering if there is funny business happening within the lens, say something like the AF operating during the exposure or mechanical hysteresis or subtle shift in elements due to slight movement of focus or zoom rings when using a "left hand under the lens" hold. Are we sounding strange yet?


Steve

Strange indeed. To my eyes though, the vertical doubling is everywhere - all over the frame.

[C_Jones]

I have been using the K-3 II and 16-85 together for landscape and they have performed excellently together. If it was me I would check on whether I was using single point or multiple point AF and would also check on any other AF related setting. I would probably try using a tripod using single point AF first to see if the exact point of focus area was being properly focused on. Then I would try a multiple point AF setting to see if there was a difference or any major loss of detail. You may want to see what drive mode you are in also (single frame, self timer, bracketing etc.).

If you are still getting good frames, there must be something that is still working right. Maybe with testing and different settings you may find a method that works.

Good luck.

[skyclad666]

I was using the HD Pentax DA 16-85mm f3.5-5.6. It's quite possible some dirt got on the mount so this might explain it, but in the EXIF of the photos where the problem occurs I don't see any unusual focal lengths. They are all within the range of the lens and plausible for the shot. How did you find out the camera was adjusting for 1600mm, did it show up in the EXIF?

On my K-1, I configured the "tile menu" with focal length adjustment in one tile. I guess I forgot to adjust it when I put my 15mm manual lens. Or I made a mistake during adjusment because 1600mm is a few steps before 15mm. Anyway, the 1600mm appeared in the EXIF so my explanation is not correct in your case. If the EXIF indicates 53mm, it is a reasonable value for a 16-85mm and the IBIS should not vibrate like that. Strange behaviour...

[Roquefort]

Thanks for the replies. I sent it away for repair, we'll see what comes up.