Nasty K-x mirror slap problem...

[joe_jackson4]

<p>I've been experiencing some very annoying problems with the K-x when using shutter speeds around 1/45s to 1/180s or so... Seems I'm not the only one:</p>

<p><a href="http://www.pentaxforums.com/forums/pentax-dslr-discussion/84372-we-seeing-pattern-k-x-soft-shutter-speeds-around-1-100-1-200-a.html">Linky</a></p>

<p>I wondered if the harsh mirror slap was causing vibration, so did a little tripod test at 1/90s... Here's a 100% croperoo of a tripod-mounted shot using the handy two-second timer (SR switched off and auto-MLU...)</p>

<p><img src="http://koti.welho.com/pwilkins/01.jpg" alt="" /></p>

<p>And here's another tripod-mounted effort, but this time without using the self-timer (SR switched off, no MLU...):</p>

<p><img src="http://koti.welho.com/pwilkins/02.jpg" alt="" /></p>

<p>Ya dig that...? Me neither... Most unpleasant...</p>

<p>I did precisely the same tests with the K200D with no problems at all, so it's clearly the K-x being a bit crap here... And it's VERY repeatable with my cam. I took about ten shots each with MLU on and off and the crappiness was very consistent.</p>

<p>Not impressed.</p>

 

[joe_jackson4]

<p>Those shots are with the the DA35 Ltd, BTW... (No flash for this test, obviously, so it was ISO 800 and f/2.8, not that it really matters here...)</p>

<p>Handheld shooting at 1/90s with SR on is sometimes OK, but often not... It's the "often not" part that's the problem... :) My guess is that the SR tries to correct the sudden, mirror-induced jolt as best it can but it isn't always successful. And it shouldn't even need to be trying, because handholding a 35mm lens at 1/90 shouldn't need SR at all...</p>

<p>I didn't notice it so much earlier, because I've mainly been shooting indoors at less than 1/20s with the kit lens... Seems OK at low/high shutter speeds, but who wants a camera that's unreliable at "average" shutter speeds...? Not even the most fervent Pentax fanboy would put up with that.</p>

<p>I'm not saying all K-x cams have this problem. But mine does, and it seems others are experiencing very similar issues... Check out the shots in this post:</p>

<p><a href="http://www.pentaxforums.com/forums/854724-post34.html">http://www.pentaxforums.com/forums/854724-post34.html</a></p>

<p>Does the motion blur in his house crop look familiar...? The Flickr info says "<strong>Exposure: 1/100</strong> Aperture:f/6.3 Focal Length:37.5 mm". Hmm...</p>

<p>I wonder if this could be helped with new firmware having a delayed shutter action, at the expense of longer mirror blackout time... Who knows... In the meantime, I guess it's a trip back to the shop next week.</p>

[trung_tran2]

<p>I think it would be more fair if you do a 3rd shot with timer, no SR, and no MLU. As your current test indicates it's possible that you moved the camera while pressing the shutter button -- perhaps you are shooting on carpet.</p>

[joe_jackson4]

<p>Nah Trung, no carpet... I have a very nice wooden floor, thanks. It doesn't move much...</p>

<p>I first noticed this "micro-shake" issue when I shot outside and - looking back - used a slightly higher (compared to my usual indoor settings...) shutter speed. I remember mentioning it in my little "review"... Quote:</p>

<p>"Another minor (so far...) issue is that the SR seemed to go ever-so-slightly wonky on me when I was taking a few profoundly artistic test shots of a bush in my garden a few days ago. Just for a few shots in a row. The results almost looked like it was set for the wrong focal length or something... And yet the EXIF looked OK... Hmmmmm... Some kind of funky firmware bug...? Or is the sheer clackiness of the thing causing some wacky, shutter-speed-dependent, SR-related problems...? Who knows... Anyway, the SR has been working just fine since then... Guess I'll just keep an eye on it. And hang on to the till receipt."</p>

<p>It's the camera, and it's going back ASAP. Sorry, but I for one am not paying 600€ for something that doesn't work properly. My other cameras don't have this issue, so why should I put up with it with this one...? Answer: I shouldn't.</p>

[wayne_campbell]

<p>Oh noooo...........<br>

Just when you thought it was safe to go back into the water............</p>

[miserere_mei]

<p>How about the same shot with a remote release...?</p>

<p>And then another one with SR turned ON....?</p>

[hinman]

<p>This concerns me as I do find K-x to be on the loud side with the mirror slap. I shoot for the last month with many pictures done at 1/100 of sec, some are soft but I find mostly due to user errors. My question to Paul is that why is the mirror slap problem not showing at slower shutter in 1/20 sec but in 1/90 sec for you. </p>

[hinman]

<p>Also, there is the suggestion from others that the hand-shake sign for SR is not observed in the shooting. By that I mean, user can take the shutter without knowing that the SR is not engaged. There are some discussions on SR being not engaged when user take a soft picture not knowing that SR has not been engaged.</p>

<p>Nonetheless, the mirror slap with vibration is a concern. It is noted in dpreview saying the SR is not efficient and I wonder if it has something to do with the strong vibration from the mirror slap. Other with ideas and comments, please jump in.</p>

[david_klaffenbach]

<p>Have you actually isolated between mirror vibration and vibration from pressing the shutter button? If I understand correctly you changed two things at once, so you may not know the real root cause.</p>

[michael_kuhne]

<p>This is potentially a serious shortcoming. It may share this shortcoming with other bodies, if they were so tested, especially compact models. I don't know how the Canikons compare. But I do know that after going back to my K100DS after using just my K200D and K20D for quite a long time, I was rather startled by the K100D's Ker-CLUNK sound upon every shutter release! I had gotten used to the much quieter performance of my two newer, robustly-built cameras. Upon testing, the K100D may exhibit a similar problem as the K-x under similar test conditions.</p>

<p>Would any having owned both a K100D and K-x be able to compare the noisiness from each as being similar?</p>

<p>Any mechanically-induced vibration will likely be worse when the camera is used on a tripod. It must be recognized that effective vibration is different under the circumstances of what else is connected to the camera body, which includes your hands and also various lenses. Your hands on the camera would, to some significant degree, absorb and damp out vibrations. Larger lenses with greater mass also have some damping effect. The highest amount of vibration has been shown to change in amount, and with different shutter speeds when having different mass added to a camera body. It is noteworthy that dpreview still did arrive at very fine IQ results in their test of the K-x.</p>

<p>This is something Pentax should look to improve in their next K-? lightweight compact model that will supercede the K-x. Certainly, with this camera, the MLU feature will be of great importance when using on a tripod. At least it HAS a MLU feature- more than can be said for some other brands' entry-level cameras.</p>

[ray_brown3]

<p>Seems to be an issue with a "few" kx kits.</p>

<p><a href="http://www.pentaxforums.com/forums/pentax-dslr-discussion/84372-we-seeing-pattern-k-x-soft-shutter-speeds-around-1-100-1-200-a.html">http://www.pentaxforums.com/forums/pentax-dslr-discussion/84372-we-seeing-pattern-k-x-soft-shutter-speeds-around-1-100-1-200-a.html</a></p>

[hinman]

<p>I went back home tonight and try to pay attention to both the SR and mirror slap just to be sure on my copy. K-x though a bit loud as compared to my K20D, I think s actually quieter than K100D. I do note around half a sec delay in between focus confirmation and the handshake symbol. I normally shoot upon the beep and not paying too much attention to the hexagon. Some soft pictures need to be reviewed in the exif and see if SR is activated or not.</p>

<p>But Paul's problem is not related to SR as his test shots are trying to iron out the vibration from the mirror snap. I hope he reports back if can further test with remote control or other newer findings.</p>

[shots worth sharing]

<p>Hmmmm, there really does seem to be a pattern here. A couple of "disappointed w/K-x " threads have popped up on Pentax Forum which may be related. All this simultaneous with the positive dpreview-<em><strong>arghhh!</strong> </em> . Pentax had better get on this fast and hard.</p>

[michael_kuhne]

<p>I am encouraged by the recent dpreview K-x test regarding SR. They use 4 categories of performance- sharp, slightly soft (mild blur), very blurred, and extremely blurred.</p>

<p>Their test with SR "OFF", using a 50mm Pentax lens, handheld shots, shows that at 1/60 sec the number of shots that are sharp come in at 80%. The remaining 20% come in as slightly soft (mild blur). Under the old standard rule for shutter speed, this is what one would expect for a 50mm lens. In fact, for a DSLR it could be transposed as 1/75 or 1/90 sec being the minimum standard for consistent sharpness of a 50mm lens on an aps DSLR. The test also reveals virtually 100% sharpness at 1/125 sec shutter speed.</p>

<p>Just how effective SR is in this model is another matter. By their test, it looks to be close to the K100D in this aspect.</p>

<p>Years ago, Pop Photo, under Herbert Keppler, ran a series of tests as to the effects of MLU on IQ. In general, as I recall, more sturdily-built camera bodies produced less vibration when mounted on a tripod than did bodies of lighter construction quality. Especially if the sturdier camera's mechanism was engineered to be quieter as well and produced less impact to begin with. This was not always predictable. The large, heavy Nikon F5 produced more vibration without MLU than did some smaller, lighter models. It is also not a very quiet camera. At the other end of the weight scale, I have noticed my small, ligtweight ZX-5n to be an exceptionally quiet-operating body, which has no MLU but may have little need in that regard. My ZX-L and MZ-S are pretty quiet also, but of course the MZ-S has an MLU feature anyway. So sturdier, thicker construction is a plus for less vibration, as is a quieter, more damped mechanism.</p>

<p>As the old Pop Photo study indicates, it is hardly surprising that a Pentax DSLR body with exceptionally sturdy construction, AND having a quieter mechanism- the K200D, would produce far less vibration when mounted on a tripod with no MLU than does the K-x, or the K100D for that matter.</p>

<p>Nonetheless, dpreview's excellent test shows that the K-x does indeed perform easily within the standard in handheld use.</p>

<p> </p>

[joe_jackson4]

<p>OK folks, I've taken more outdoor shots and this thing definitely has a distinct case of the jiggles... Having to sometimes retake an outdoor handheld shot five or six times to get a decent one (with a 35mm lens at 1/90s...!) is extremely irritating, as you can imagine... I mean, this particular example would be the world's worst stopped-down, low-ISO, scenic-shooting camera... It would ruin many a nice holiday snap, that's for sure.</p>

<p>Having said that, it's been behaving itself well when picked up for its intended use (indoor snapping at low shutter speeds...), so I'm currently in two minds whether to bother with the hassle of returning the bloody thing or just hang onto it as my indoor "junk cam"... Well, that was the old K100D's job, but yep, this one is much faster to use and is better (well, in some ways...) in low light. In fact, it's been so easy to use indoors that it would be a real shame to get rid of it now, I must admit.</p>

<p>BTW, the most convenient, lightweight indoor setup I've found (for my personal purposes...) is to use the DA35mm, two-star JPEGs, B&W mode, Auto ISO, max contrast, shadow and highlight correction on, NR off, high key +1, fine sharpening, daylight white balance, and Tv mode at 1/10s. And just leave it like that. Well, unless it's very, very dark, in which case it may be better to pop on the chunky Sigma 30/1.4.</p>

<p>Anyway, this has been giving the much-appreciated "P&S convenience with low light capability" I was looking for... Just point camera, focus and press button... With the settings above, the K-x keeps the aperture wide open and just ramps the ISO up and down in 1/3 stop steps as required... Excellent. I never have to touch the rear dial... :) And it gives acceptable-to-me, gritty, grainy B&Ws at silly ISOs that are making my G11-owning mate weep into his RAW files... :) Just a shame it doesn't work in my garden...</p>

<p> </p>

[michael_kuhne]

<p>Thanks for your report, Paul. There does appear to be some problem going on if you have trouble getting a good quality shot at 1/90 sec, of a still, solid subject using a fine 35mm lens! I am also looking forward to Hin's reports coming through, both with and without SR, for hand held shots.</p>

[r.t. dowling]

<p>I recall that there were similar reports about the Olympus EP-1 producing good results at high and low shutter speeds, but blurry results at mid-range shutter speeds. The major difference is that the EP-1 doesn't have a mirror.</p>

[mike_robillard1]

<p>I just performed the same testing on my k-x. I did <em><strong>not</strong> </em> see the issues the OP is describing.<br>

I used a Pentax k-x at 1/80sec with the kit lens at 55mm.<br>

I performed 3 tests:</p>

<ol>

<li>tripod mounted, SR off, no MLU</li>

<li>tripod mounted, SR off, with MLU</li>

<li>hand held but <strong>very</strong> well braced, SR on, no MLU</li>

</ol>

<p>I evaluated at 100% and couldn't tell the difference between test #1 and test #2. While I could see a noticeable difference between the hand held shot and the tripod mounted shots, I did not see anything like the effect reported by the OP.<br>

<strong>I think there is a very real possibility that the OPs camera is defective</strong> .</p>

[joe_jackson4]

<p>I just got around to downloading a few outdoor snaps that I took a few weeks ago, when I first had the cam and was messing around with this and that... Here's a good example of the jiggly effect that I'm seeing way too much of when I look closely at the pics...</p>

<p><a href="http://koti.welho.com/pwilkins/IMGP0586.DNG">http://koti.welho.com/pwilkins/IMGP0586.DNG</a></p>

<p> </p>

[joe_jackson4]

<p>BTW that pic is just one example of many shots I have here that look like that...</p><p>Sure, we're all free to sit around pondering the reasons for this effect - as are the people at Pentax, of course - but the end result for me is that pics at these middling shutter speeds have around a 25% success rate... I guess common sense says I should just return the thing ASAP, and hopefully get a copy which actually works properly.</p>

[jeremy_corbin]

<p>Paul, not sure if I missed something, but that raw file you posted just a bit ago was 160x120. When I tried to zoom in to see it better it wasn't helpful to say the least. Got a bigger file (pixel-wise) I can take gander at?</p>

<p>I vote return your K-x for another copy. You have the benefit of the warranty by purchasing something new. Why not use it? :-)</p>

[joe_jackson4]

<p>Jeremiah, not sure what the problem is there for you with that RAW file, but here's a full-size JPEG, extracted courtesy of the handy little "<a href="http://www.rawworkflow.com/instant-jpeg-from-raw-utility/">Instant JPEG From RAW</a>" utility:</p>

<p><a href="http://koti.welho.com/pwilkins/IMGP0586.jpg">http://koti.welho.com/pwilkins/IMGP0586.jpg</a></p>

<p> </p>

[michael_kuhne]

<p>Since in the course of multi responses and reports, it has been shown that some K-x owners have this problem, but most do not, I have to assume this is a QC issue. I am not an engineer, but knowing that SR requires a movable sensor, without careful assembly it would be reasonable that the movable sensor might be more susceptible to vibration from the mirror. Evidently, design engineers have taken this into account, as other Pentax models have not had this problem, and likewise with most K-x samples out there. </p>

<p>I'd get a replacement ASAP, and if that does not pan out, if it were my camera I'd contact Pentax and have them fix it. When it comes to their attention, presumably they will tighten manufacturing QC to address this issue.</p>

[joe_jackson4]

<p>More K-x jiggliness:</p>

<p><a href="http://forums.dpreview.com/forums/readflat.asp?forum=1036&thread=34086647">http://forums.dpreview.com/forums/readflat.asp?forum=1036&thread=34086647</a></p>

<p>One of the respondents there claims to have had the same issue and solved the problem by resetting the camera... I'll give it a try... :)</p>

[joe_jackson4]

<p>Well, as for the OP in the DP Review thread above, resetting didn't seem to help here... Still getting jiggly pics...</p>

<p>I'll give it one last try outside tomorrow and if the results are still rubbish then I guess it's going back to get sorted out one way or another.</p>