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Forum: Pentax DSLR Discussion
02-19-2011, 04:45 PM
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My K-x was one of the unfortunate few that suffered from double-image blur at shutter speeds between 1/80th and 1/160th of a second. I posted a thread about it here (https://www.pentaxforums.com/forums/pentax-dslr-discussion/96746-k-x-shake-ca...technique.html) after I'd had the camera for a few months. In the end it went back to CRK for repair, and they "dismantled unit to S/F new gyro circuit assembly".
I then went to SE Asia for 5 months and lo and behold, the problem reoccurred. So when I got back home I sent the camera (along with photos showing the issue) back to CRK, who very gracefully agreed to repair it even though it was a week or two out of warranty.
This time they "dismantled unit to S/F new main PC board and gyro circuit assembly". I've taken around 100 shots at the shutter speeds that used to show the problem with the same lens I used to use and so far every shot has been nice and sharp, with no blur. I've also taken a couple of hundred other shots (confirming that my new Sigma 17-70 2.8-4.5 is back focusing - when will it end?) of which plenty have been at the relevant shutter speeds, and everything's looked good.
So I guess either it was the gyro assembly that was the culprit (and I was unlucky enough to get two bad ones in a row) or the main PC board. Unfortunately now the camera's speaker doesn't work so I get no focus confirmation beep or sound in movies. But I can live with that.
Edwin
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Forum: Pentax DSLR Discussion
05-20-2010, 01:37 AM
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In the end I took my camera to the supplier here in Sydney (CR Kennedy) and they sent it off to Melbourne to be looked at. Judging from the receipt it would appear they just replaced the gyro circuit block:
Gyro Circuit Block
Repair to Pentax K-X Digital SLR
Dismantled unit to S/F new gyro circuit assembly
Reassemble and check
Cost for the part would've been $6.67 were it not under warranty. Camera is black, serial number 344XXXX. Based on a couple of quick test shots the problem seems to have been resolved, but I'll let you know if this changes.
Edwin
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Forum: Pentax DSLR Discussion
04-11-2010, 05:09 AM
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I've done a whole bunch of testing this weekend but these two sets of photos probably best demonstrate the issue. Photos were taken with eneloops (still full green), at 18mm, camera held vertically, shake reduction off, latest firmware (1.01.00.10 - another silent update). I took two shots at 1/30 and then four shots at 1/100, right after each other. The second shot at 1/30 shows that I can take a reasonably still shot at that speed. What's interesting is that the first shot at 1/30 is blurred, and soft - but the bad shots at 1/100 look (once again) like double-exposures. On the left hand side of each crop you can clearly see each of the small horizontal lines has doubled.
Based on my other testing (I'll post the results when I've finished collating all 120-odd shots) the issue seems much worse with the camera held vertically.
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Forum: Pentax DSLR Discussion
04-08-2010, 07:43 AM
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I've verified that SR was enabled by looking at the exif data in the Pentax Digital Utility 4 program - does this mean the shake reduction HAD actually settled in and was active by the time the photo was taken or does it just mean that shake reduction had been selected on the camera?
X-sync speed for the K-x is 1/180 right, the fastest shutter speed possible with flash?
I'll do more testing over the weekend and see what I can find. If I do end up returning it to the distributor at some point I'll let you all know what happens, might be interesting to see what they say is faulty (if anything).
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Forum: Pentax DSLR Discussion
04-08-2010, 06:09 AM
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All photos were taken using the viewfinder, I've rarely used liveview so far. Thanks for the tips re: technique Lowell, I'll keep them in mind for next time and see if that improves things. I suppose the frustrating thing is that these problems aren't consistent - some shots are amazingly sharp, and a few have heaps of blur like the ones I attached earlier. For example I took several five of that cruise liner, three were sharp, one was blurry (or rather, really really soft which is what I would've thought you'd see if I was the one holding the camera unsteadily) and I've attached the other one. What I also find curious is that the shake on the picture I attached seems so well defined (if that makes any sense) - as if two separate exposures were taken, one aimed a few pixels higher than the other.
A while back I took a focus test chart and took a few dozen pictures of it at 1/100 and 1/125 at a focal length of 55mm, all in landscape, with shake reduction on and off. From memory I focused once and then switched to manual focusing so that the results weren't dependent on focus accuracy.
From what I can tell the results were as expected - at each shutter speed there were some slightly blurry shots, and turning on SR seemed on average to give sharper photos with less blur. I also took a reference shot at 1/250 to see how sharp the ideal picture would be (first attachment), which to me looks pretty good.
The blurriest photo taken at 1/100 with SR on is the second attachment, and even that doesn't look to me to be THAT bad. The third attachment shows an average sort of shot at 1/100 with SR on.
So my first test seems to indicate the camera is behaving as expected, but these obviously blurred shots keep on cropping up. I'd like to run some more tests (as exciting as they are) but there are so many variables (landscape or portrait, freshly charged or nearly empty batteries, at least 4 different shutter speeds to test, SR on or off, 2-second timer on or off, tripod or hand held etc) I could be shooting hundreds of test shots before I reach a conclusion.
Anyway, thanks for your responses. As I said, next time I'll concentrate more on my technique holding the camera steady and see what happens.
Edwin
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Forum: Pentax DSLR Discussion
04-08-2010, 04:09 AM
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I hate to add to the K-x mirror-slap scaremongering but I'm beginning to think I actually have an issue with mine. Having said that I'm new to SLR photography (I've had the camera for about three or four months) so I'm cognisant of the fact that the issue may well be with my technique and not with the camera. So I thought I'd let you more experienced lot decide for me.
Hopefully GIMP has saved the exif data but if not:
Pic 1: F11, 1/80, 32mm focus
Pic 2: F8, 1/100, 40mm focus
Pic 3: F10, 1/125, 55mm focus
Now it seems to me that with those sort of focal lengths and shutter speeds I should be able to get pretty sharp details, even as a beginner. All the pictures were taken using centre point focusing, and I've verified that SR was enabled for each one. This hasn't been an issue with all my shots but as far as I can tell I haven't had any issues with pictures shot at 1/160 or faster, irrespective of focal length (I also have the 50-200mm kit lens).
I know this has been gone over before, but what would be the best way of verifying if the fault lies with the camera? Taking dozens of hand-held shots at 1/80, 1/100 and 1/125 using the 2-second timer and comparing them to normally-taken pictures? Live view vs non-live view? Tripod (which I don't have, and may possibly dampen vibrations) vs hand-held? I'm going overseas in a few months so if I do have a problem that would be repairable under warranty I'd like to sort it out now, but I don't want to send the camera away if I don't have to.
Let me know if you'd like me to post further samples, and thanks in advance.
Edwin
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