K-x blur problem or user error!?

So I bought a K-x a few months ago as my first DSLR. I love it and took many pictures with it. Then, many people started complaining about blurry pictures taken with the K-x. The problem was somewhat baptisted the K-x blur "problem" (as to know if it is a real problem or just a few faulty K-x, I don't know).

I tried not to worry too much about it and just enjoy my camera. But as I am trying to improve my photography skill, I can't help but notice that some of my image seems unnecessary blurred. I am more than willing to blame it on me though before I say that my camera has a problem, but I would like to know what you guys think of the shot below. It was converted from RAW to Jpeg using lightroom 2 with standard sharpening applied. As I was adding a nice blue sky and was getting rid of some unattractive part of the image (some dirt on the grass and such) in photoshop, I noticed that the golfer in the middle was really blurred - and the pattern looked a lot like some images of the k-x blur problem that I have seen on this forum many times.

Image was taken a 1/125, 18mm, iso 200 and f: 6.3. I understand that at 18mm, my kit lens won't be very sharp, but still, is that normal ? (center focus used, on the golfer).

full image :





very tight crop on the golfer





tight crop on some of the branches





Thank you all in advance for your input

The 18mm focal length and 1/125 shutter speed, and double image blur all point to the 'double image blur' problem.

However one image is not proof, it could be blur due to camera shake.

Try shooting several images of a high contrast target, at 18mm and 1/125 sec, hand held, with SR On . Wait for the SR Ready indicator each time.

If you find that a fair proportion of shots are blurred, then do a further test to confirm the problem is due to the camera and not to your technique: shoot the same target again, also at 18mm, but using a much slower shutter speed e.g. 1/20 sec. But this time, make sure that SR is Off .

If the second set of images is sharper, you've proved that you're camera is faulty and hopefully you can return it.
--
Mike
http://flickr.com/rc-soar

Thank for the quick answer. I do agree that further testing would be good. I did took a few other pictures that day in similar condition, and as far as I can tell for now, mostly the portrait oriented pictures came out blurred aka doubled. I will try to shoot some similar pictures at slower speed, like 1/30 to see what happens.

Any other thoughts?

You can't test the Kx image blur issue on a moving subject like a golf swing. The golfer's movement will create blur at 1/125 even with a perfect camera.

Take Mighty Mike's advice and take series of shots of a stationary object like a sign, with and without SR.

Kp0c said:

I noticed that the golfer in the middle was really blurred - and the pattern looked a lot like some images of the k-x blur problem that I have seen on this forum many times.

Image was taken a 1/125, 18mm, iso 200 and f: 6.3. I understand that at 18mm, my kit lens won't be very sharp, but still, is that normal ? (center focus used, on the golfer).

Click to expand...

I to have noticed, especially at 1/125 sec exposure, that sometimes I get the double edge blurring. Mind you, you have to zoom in to at least 10x to notice and I have printed some of these suspect images at 4x6 with no noticeable blur.

As for taking the picture of the golfer, firstly, the tee marker in front of the golfer is not moving but does show the blur, secondly the golfer has finished his swing and the club is coming to a stop. It is not like the picture was taken when the golfer was striking the ball at maximum club head speed.

What I have tried to do is stay away from 1/125 sec exposures as this seems to be the sweet spot for any blurring problems.

Bret

I've noticeed similar cases. Using a prime lens (in my case, A 50/1.7) will probably improve the images. Whatever lenses (A 50/1.7, A 35-7- 4, DA L18-55/55-300) and settings I used, almost all images seemed to have a thin greyish film on them though all in focus. I wonder if I had to invest in one of the noble & expensive princesses (a name in China for the FA43mm F1.9 Limited, FA77mm F1.8 Limited & FA31mm F1.8 AL Limited) to achieve crystal clear and nice images.
All the best,
--
Yang

Kp0c said:

mostly the portrait oriented pictures came out blurred aka doubled.

Click to expand...

Some people - including the original poster of this problem on DPR - have also reported that it's worse in portrait orientation. So again this ties in. (I personally didn't do any portrait mode tests with my first K-x as the problem was obvious enough in landscape mode.)

--
Mike
http://flickr.com/rc-soar

The kit lens at 18mm F6.3 should be very sharp in the center of the frame. Anyway, lack of sharpness never results in double images.

It seems that your camera has the K-x blur problem. Double images like that of the golfer are not caused by subject movement or hand shake at 1/125, 18mm.

Subject motion blur affects the subject only (in the image the tee marker has the exact same blur), and does not create double images unless the subject was frozen in one position for a long time then rapidly moved to another position and frozen there. Mostly it looks like streaks and a general softening of whatever was moving.

Hand shake blur affects the entire image and can take on many different looks, but double images is not one of them. At short exposure times it often looks like streaks in a single direction, while longer exposures get affected by movement in many directions.

--
My Flickr:
http://www.flickr.com/photos/36164047@N06/

So your camera had the problem too ? Did you have it serviced and is it working any better? (assuming it was repaired!).

Thanks!

Hi Karl,

Yes I had this problem on two cameras, and both were returned to the retailer. Another sample in the shop had the same problem as well so I passed up on that as well. As it was all getting a bit silly, I decided to revert back to my old *istDS for a couple of months, before I finally got a K-x which worked properly.

Below is a post showing the results of some tests which I did to demonstrate the problem in the first cam:

http://forums.dpreview.com/forums/read.asp?forum=1036&message=35755997

The general idea is: if you get badly blurred images at a certain shutter speed with SR enabled, but consistently sharp results when using a slower shutter speed and SR dis-abled , then there is clearly something wrong with the camera. The shutter speed for the SR Off tests should be chosen to be below the blur problem range i.e. around 1/30 second or even slower if you're steady enough.

The cause of the problem is irrelevent as far as exchanging the camera is concerned, so I have steered clear of the endless speculation as to the reasons - it's up to Pentax to find a fix, or else to replace the camera and to their credit I had no problem replacing both cams.

As to trying to get the first cam fixed... both Pentax UK and Johnson's Photopia (the UK service agent) were sent the photographic evidence, and they both accepted there was an issue. However the service guys could find no mention of it in the service database and didn't want to fiddle with it, which is why I exchanged the cameras.

Regards
--
Mike
http://flickr.com/rc-soar

I recently returned from a 5 week trip to Japan, Hawaii, California. 6,000 photos with my K-x.

I noted that a few (maybe 30?) photos with shutter speeds around 1/80-125 seconds were had this characteristic Pentax slap motion blur.

However, the vast majority (well over 90%) of my images, taken at the same shutter speeds (and with both short and long focal lengths), are absolutely razor sharp.

Also, I've seen this blur in a few images with 1/40-60 seconds, and one unfortunate at 1/320 seconds.

For me/for my camera, it seems that three factors predispose to this blur:

1) Me not waiting for the shake reduction to indicate it's ready,

2) Being in a situation where I was excited/careless/rushed

3) shutter speeds slower than 1/160 seconds.

I don't defy other K-x users' problems, or the thoruough K-7 paper on the same issue, but for my camera it doesn't seem to be a systematic defect, as so many of my images are sharp. Yet, it seems that there is a Pentax-esque kind of motion blur that under some unfortunate circumstances pop up and in some defective units are vastly excarberated/pop up systematically. I assure that my blurred images have the same kind of blur mentioned by others.

I've also seen old samples from K10D and K100D models with the same kind of blur. Could these kind of images sometimes also result in non-defective Pentax cameras as a result of how the in-body stabilization is built (or, misused)? That's what I think.

Schoug said:

Could these kind of images sometimes also result in non-defective Pentax cameras as a result of how the in-body stabilization is built (or, misused)? That's what I think.

Click to expand...

Sure, you can misuse a camera just the same way you can slide off the road in a Ferrari.

The more important question is whether your camera is working properly in the first place, and you can determine that by doing your own controlled tests.

--
Mike
http://flickr.com/rc-soar

Model Mike said:

The more important question is whether your camera is working properly in the first place, and you can determine that by doing your own controlled tests.

Click to expand...

Which is what I've done quite a lot, and when I try shoot at say, 1/100, the images are sharp, whether I use SR or not. Last time I compared it with 1/40, and both SR and no-SR images were sharp then as well; not a huge difference between the shutter speeds.

The only times I've been able to recreate the blur is when I don't wait for the SR 'ready' signal (the hand). Maybe it's created by the button press, but who knows. Maybe it's just random or dependent on something else I/we cannot decipher.

My point is, I occasionally get this blur, identical to the blur reported by users experiencing it consistently (?). The special kind of ghost/double image blur (3-10 pixels) is nothing I've seen when using other cameras. So, maybe, the shutter slap is only a special case of a more general situation: when the SR system can't fully cope with a motion stress, and the nature of the moving sensor in Pentax DSLR's creates this rather special motion blur. Just my two cents...

Im facing the SR blur issue with my K-x. I took a large number of pictures at 100sec shutter (holding the camera in vertical/portrait orientation) and about 40-50% are blurred. After collecting all the blurred ones in a separate folder, I noticed something interesting. If you view their EXIF data (by pressing cmd+i on Preview for Mac), they all say "129" in the " ImageStabilization" field.
All the non-double-image pictures have the value "5" in that field.

I still haven't figured out whether that value represents the amount of shake correction applied or something else..

can someone please confirm this correlation?

Your Kx is probably working correctly. In Kx images, EXIF tag 5C contains 4 values related to Image Stabilization which I believe are vendor dependent. The Apple EXIF reader may not parse them completely for the kx, and is showing you the decimal value.

The 129 probably means "Not Stabilized" meaning the SR system did not have enough time to initialize. The K-x records this value when you fully depress the shutter before the SR Ready icon (green hand) appears.

The 5 value probably means "Stabilized".

Try taking a shot after carefully waiting for the SR ready icon to show in the viewfinder. Take another shot without waiting for SR ready. You can do this easily in manual focus mode by just fully pressing the shutter.

See what the EXIF says.

BTW - PhotoME is an EXIF reader that shows the vendor specific tags, but it is Windows only. I don't know if there's Mac equivalent. If you post the images with EXIF intact, I can tell you what PhotoME says.

hassan987 said:

Im facing the SR blur issue with my K-x. I took a large number of pictures at 100sec shutter (holding the camera in vertical/portrait orientation) and about 40-50% are blurred. After collecting all the blurred ones in a separate folder, I noticed something interesting. If you view their EXIF data (by pressing cmd+i on Preview for Mac), they all say "129" in the " ImageStabilization" field.
All the non-double-image pictures have the value "5" in that field.

I still haven't figured out whether that value represents the amount of shake correction applied or something else..

can someone please confirm this correlation?

Click to expand...

Here are the Pentax EXIF tag values for SR:

http://owl.phy.queensu.ca/~phil/exiftool/TagNames/Pentax.html#SRInfo

Thank you for the prompt reply.
Here are some blurred image files.

Did not work. When I downloaded the images from your DPreview gallery, they had truncated EXIF without the Manufacturer tags.

Oh, sorry, I have emailed the files to you. Thank you.