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12-16-2010, 01:15 AM   #1
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Is it the camera or the lens?

Having some issues with my K20/Tamron 17-50. No matter the FL, aperture, speed or object distance all the images appear soft to me. I've run the usual BF/FF test with the chart, and there's so little variation front/back that it can't be significant. This image is an example out of 82 similar natural light images that are all soft (Av 100 ISO spot metering, lens set at 30mm at f/11 @1/30th). I'd expect everything from 10 feet to infinity would be sharp . I got the same results with a borrowed 18-55wr, otherwise I would have assumed it's a lens issue. In this case, could it be the camera?
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12-16-2010, 05:57 AM   #2
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Have you tried using a tripod? It could be motion blur. Just a suggestion.

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12-16-2010, 06:20 AM   #3
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Are you in the habit of using a UV or protection filter on your lenses? So many of those are simply crappy quality and cause problems like softness (and worse).

Also - what happens if you set the camera on a sturdy tripod, manually focus at say f5.6 on a flat test target (eg the ISO 12233 test chart), and use the self timer to let off a shot?
12-16-2010, 06:38 AM   #4
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Focus manually and stopper down!

Tripod is a good suggestion........How about a setting in your K20.....?
The image looks OK to me...the distance...looks naturally detailed no more or less. Can you beg, borrow or steal a fixed focal length length lens and repeat the experiment. Focusing manually rather than auto focus. Stopper down to F22 or slower.................................

12-16-2010, 08:42 AM   #5
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With that size jpg it is hard to make a judgment about any unsharpness. Since you have the problem with multiple lenses, then it would seem to be an issue with the camera or its use.

Here is what I would check:

1) Is shake reduction on?

2) Does the problem exist at all shutter speeds?

3) What is the point of focus? In the shot displayed, the thorny plant in the foreground may be too small to lock reliably with autofocus.
12-16-2010, 09:02 AM   #6
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I don't see softness, just dullness. In fact it kind of looks oversharpened. I agree though, it's pretty hard to see softness at this resolution. Some thoughts:
- The Tamron 17-50 has a reputation for back-focus front-focus, regardless of camera make.
- If you're using Natural image tone, try switching to Bright or Landscape, especially for nature photos. My all-purpose default with the K20 is Portrait. It's a nice balance between dull looking Natural and the punchier Bright and Landscape settings.
- Do you see any difference between raw and in-camera jpeg?
- Try posting a full sized photo or some 100% crops so we can see the issue more clearly.
- Already mentioned, but does a tripod and 2s lockup make a difference?
- Have you tried shooting any test charts or newspaper?

Last edited by audiobomber; 12-16-2010 at 09:09 AM.
12-16-2010, 09:46 AM   #7
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I would try manual focusing to rule out the lens. Taking pictures of a piece of paper is fun for about 1 second and then it gets old and gets you nowhere. With an 18-55 lens (any version) I wouldn't expect Anything at infinity or anywhere near it, to be 'sharp'.

I'm going by memory here so don't think I'm stating this as fact. Some of the early Tamron 17-50 lenses did have problems, perhaps it seems, decentering.

I don't remember specifically about the K20d but the K10d would sometimes miss focus depending on the WB. That was in Tungsten light though when using AWB. It's a long shot but you might try adjusting that and see what happens.

12-16-2010, 11:16 AM   #8
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QuoteOriginally posted by GeneV Quote
3) What is the point of focus? In the shot displayed, the thorny plant in the foreground may be too small to lock reliably with autofocus.
That's why I would set up a different test, where you can identify the point of focus. If you're at an angle to a brick wall and shoot at f2.8 on a tripod, you can see the place where the lens has focused. Manually focus to help get a nicely detailed part of the wall for a target. Keep the camera in manual focus so it doesn't refocus on you. Then change to an aperture where everything should be sharp and reshoot. Now you can look at the first image to see the point of focus, and the second image to see the (hopefully) maximum sharpness. Yeah, you'll have some boring, non-real world shots, but you don't have to submit them to contests.

12-16-2010, 01:03 PM   #9
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Thanks for all the input. Taking the various suggestions, here are two images @ 100% crop of the same 35mm shot f/5.6 @ 1/40th, ISO 100 ... on the left with IS off/2 second delay on the tripod and the other with IS on and handheld. It looks like operator error to me,
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12-16-2010, 02:12 PM   #10
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QuoteOriginally posted by FHPhotographer Quote
It looks like operator error to me
This might be a useful read then:
Reducing Camera Shake with Hand-Held Photos
12-16-2010, 02:24 PM   #11
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I don't know that lens, but sharpness varies widely from lens to lens.

But I totally dismiss the idea of a tripod:

For 99.99999% of your shots, you're not going to use one. And with SR, you don't have to, ESPECIALLY for shots focused to infinity.
12-16-2010, 02:38 PM   #12
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Tripod needed for testing

Actually it is really important to use a tripod for testing. It elimainates one of the variables affecting sharpness. It is possible to use the camera in a way that will give poor sharpness no matter what kind of image stabilization or SR you use.
12-16-2010, 04:47 PM   #13
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QuoteOriginally posted by pentaxus Quote
Actually it is really important to use a tripod for testing. It elimainates one of the variables affecting sharpness. It is possible to use the camera in a way that will give poor sharpness no matter what kind of image stabilization or SR you use.
I agree. If you want to see if a lens is sharp, you want to do it under ideal circumstances. If you find that the lens is sharp under ideal circumstances, then the next thing to figure out is what you are doing wrong that is causing the softness.
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