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05-24-2010, 12:40 PM   #16
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Your aperture is at least part of the problem

See this review of the 18-55 kit lens in Lenstip.com and you will see that shooting at 18mm with a wide open aperture is one of the least optimal settings for this lens.
Pentax smc DA 18-55 mm f/3.5-5.6 AL II review - Image resolution - Lenstip.com
Expect significantly lower resolution at this setting. Also notice the relatively poor performance at f5.6 at 55mm. I try to keep my aperture in the sweet spot of f8 whenever possible. I recommend you switch to aperture priority to better control lens performance. If you are shooting a subject close up and wish to isolate it using a wide aperture, then go wide by all means. But you will do better to use a 35mm setting and back up a bit. And just don't expect to make 100% blowups of it and have it look great. As for your line ghosting, not sure why that is, but try your test again with settings your lens likes.

05-24-2010, 02:57 PM   #17
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QuoteOriginally posted by Ira Quote
AF-A didn't detect any real motion to change the focus, so it didn't go into AF-C.

When I use autofocus, I always use AF-S. This way I get my focus point, but can reframe the shot the way I want.
Yeah, that's kind of what I was trying to say. I know the camera didn't focus on something different as I focused on the paper and did not move the camera. Sorry if I wasn't clear and thanks for the helpful advice.

QuoteOriginally posted by sterretje Quote
Just a note:

The manual advises to switch SR off when using a tripod. The same will apply when having the camera on a flat surface. That will explain the bad results in that specific test; the camera is trying to compensate movement that is not here resulting in blur.
Agreed. As I read, this is what I'm finding out. So, in this instance, user error accounts for the blur. Again, thanks for the insight.

QuoteOriginally posted by lectrolink Quote
See this review of the 18-55 kit lens in Lenstip.com and you will see that shooting at 18mm with a wide open aperture is one of the least optimal settings for this lens.
Pentax smc DA 18-55 mm f/3.5-5.6 AL II review - Image resolution - Lenstip.com
Expect significantly lower resolution at this setting. Also notice the relatively poor performance at f5.6 at 55mm. I try to keep my aperture in the sweet spot of f8 whenever possible. I recommend you switch to aperture priority to better control lens performance. If you are shooting a subject close up and wish to isolate it using a wide aperture, then go wide by all means. But you will do better to use a 35mm setting and back up a bit. And just don't expect to make 100% blowups of it and have it look great. As for your line ghosting, not sure why that is, but try your test again with settings your lens likes.

I will try the test with more optimal settings. I was just trying to do a worst case scenario and, from what I gather, the issues with the double imaging are more prevalent in the wide angle settings.

On a side note, I did some less formal testing in my room by the light of an incandecent bulb (much worse conditions than the previous test). My results were nearly flawless in about 20 pictures of some text from across the room with various settings in the "trouble range." I just don't get it. All I could see was some slight blur that looked more like your standard motion blur rather than the double imaging. Quite peculiar.

On another side note, I will be trying my uncle's D90 this week just to see what kind of results I get from it. This would be the only other camera I'd consider over the K-x, but if my results are significantly better, I may end up going that route. I'd hate to spend twice as much for a camera, but it's the only other camera I'd consider that's remotely in my price range.
05-24-2010, 10:26 PM   #18
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Just an update, and a rather pleasant one that has made me a happy man.

After reading around some more, I found a suggestion to reset the settings to factory defaults. This seems to have completely eliminated my problem. I haven't done real extensive testing, but now, in about 30-40 shots in the "problem zone", I have yet to see a single instance of double image. Even general blur has been reduced. Even if it isn't completely eliminated, it is good enough for me.

Also, through testing (after some advice from a poster here), I've verified that the lens definitely isn't as sharp at 18mm as, say 35. I think that was part of my issue as well. Thanks to all who helped and participated. Looking forward to becoming a full-fledged Pentaxian.
05-24-2010, 10:40 PM   #19
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Congratulations and welcome to the club.

05-24-2010, 11:42 PM   #20
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QuoteOriginally posted by Steve_B Quote
Just an update, and a rather pleasant one that has made me a happy man.
After reading around some more, I found a suggestion to reset the settings to factory defaults. This seems to have completely eliminated my problem.
Well done and glad that you solved the problem.

The Pentax dSLRs have two nice features that may interest you also: the Green button and the Green mode.

The GREEN button is very useful with the Pentax dSLRs: https://www.pentaxforums.com/forums/pentax-beginners-corner-q/60081-usage-green-button.html

The Green button will reset your settings. For example, In HyperProgram (P) mode you can change the settings using the front and rear dials. By pressing the Green button, the camera settings return to the P mode defaults.

The Green mode (mode dial Green) is the very basic settings that is completely fully-automatic. Nothing can go wrong .... and it is full proof.

Hope that the comment will help.
05-25-2010, 07:12 PM   #21
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The problem resurfaced today in bright light outdoors. But, it only seems to be occasional and I have to zoom in to 14X or 16x to see it on my playback screen. I saw it in some electrical wires against a blue sky.

I figure I can live with it though. If it's something I have to really pixel peep to see (aside from general softness it may cause an image) and only happens 10-20% of the time in the "problem zone," I can live with it because of the great pictures this camera puts out in low light and some of the other things it does really well.

Also, I can't totally rule out user error despite my attempt at controlled tests. The fact that none of my shots taken from a stable surface with SR off showed this must mean it is something I'm doing that affects this particular camera in a specific way. I can take hand held shots with other cameras (like a D90 I tried at Best Buy yesterday) at 1/100 with good results. Maybe it's the small size of this camera or something. In any case, it is capable of taking perfectly good shots when my hands are taken out of the equation.

Now, I'm off to buy the 55-300mm and the FA 50, unless there are other suggestions for around the same prices. From what I gather, these two lenses are good value and pretty good lenses.
05-25-2010, 07:27 PM   #22
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It could be a 'halo' effect due to overexposure in some situations. Try a different lens. Use exposure compensation. Also, sufficiently magnified, any image will look 'blurry'.

A couple of shots taken with a d90 in a store simply can't be your term of comparison...


QuoteOriginally posted by Steve_B Quote
The problem resurfaced today in bright light outdoors. But, it only seems to be occasional and I have to zoom in to 14X or 16x to see it on my playback screen. I saw it in some electrical wires against a blue sky.

I figure I can live with it though. If it's something I have to really pixel peep to see (aside from general softness it may cause an image) and only happens 10-20% of the time in the "problem zone," I can live with it because of the great pictures this camera puts out in low light and some of the other things it does really well.

Also, I can't totally rule out user error despite my attempt at controlled tests. The fact that none of my shots taken from a stable surface with SR off showed this must mean it is something I'm doing that affects this particular camera in a specific way. I can take hand held shots with other cameras (like a D90 I tried at Best Buy yesterday) at 1/100 with good results. Maybe it's the small size of this camera or something. In any case, it is capable of taking perfectly good shots when my hands are taken out of the equation.

Now, I'm off to buy the 55-300mm and the FA 50, unless there are other suggestions for around the same prices. From what I gather, these two lenses are good value and pretty good lenses.
05-25-2010, 08:02 PM   #23
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QuoteOriginally posted by causey Quote
It could be a 'halo' effect due to overexposure in some situations. Try a different lens. Use exposure compensation. Also, sufficiently magnified, any image will look 'blurry'.

A couple of shots taken with a d90 in a store simply can't be your term of comparison...
Good points. However, I did slightly underexpose the photos purposely so I'm not sure that would be it.

Also, I never had a noticeable problem with my Panny FZ-7 (or other cameras) with that shutter speed either, especially at wide angle. Realistically, you don't have to be very steady to get a good 1/100 wide angle shot without any stabilization.

I will definitely try another lens when I they come in (just ordered them) so I'll just go from there. Currently, I only have the kit lens and, admittedly, I don't see the problem at 35mm at all. It could very well just be poorer IQ because the lens is at it's limit when the problem seems the most noticeable.

05-26-2010, 03:26 AM   #24
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There's sample variation among lenses, and you might have a not-so-good kit lens.
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