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01-18-2014, 06:25 PM   #16
dms
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Assuming you were focused on the 13, the camera seems to be focused properly. At m=0.5 (which is about where you are at I believe) the depth of field is equal before and after the focus point--which is what you are seeing.

But the resolution (and contrast) is terrible! Hopefully it's just in the macro range--and indeed you should not expect a zoom to do well wide open at m=0.5. (I cannot say if this is what to expect from a consumer macro zoom at m=0.5--although since the f/8 is no better/actually maybe worse I rather doubt it will improve markedly if you stopped down to f/16-which ideally it should do.)

01-18-2014, 07:36 PM   #17
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QuoteOriginally posted by dms Quote
Yes shimming, The viewfinder should show the same focus as what the screen "sees." To do that the screen is adjusted till they are within spec.

Moving the sensor forward or backward (which Contax I believe tried for AF) is not easy/viable, nor is moving the mirror relative to the prism, so the screen is shifted by shims. But there is some tolerance, and it may be off. That's what I argue is the first/most basic thing to check. And then go to the AF from there.
ok, got ya, but i never use the lcd screen. in Florida sun its useless, and I would have to wear strong reading glasses to see it. with the viewfinder i dont need glasses because the diopter is adjusted for me. I can see distance for my subjects fine, just cant see anything closer than 15"

DeWolf
01-18-2014, 07:46 PM   #18
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QuoteOriginally posted by dms Quote
Assuming you were focused on the 13, the camera seems to be focused properly. At m=0.5 (which is about where you are at I believe) the depth of field is equal before and after the focus point--which is what you are seeing.

But the resolution (and contrast) is terrible! Hopefully it's just in the macro range--and indeed you should not expect a zoom to do well wide open at m=0.5. (I cannot say if this is what to expect from a consumer macro zoom at m=0.5--although since the f/8 is no better/actually maybe worse I rather doubt it will improve markedly if you stopped down to f/16-which ideally it should do.)
That was shot at about 6 ft distance using the standard, not macro mode on the lens.
The setting is one of the default settings in the camera modes,, vibrant perhaps, I didnt look.
Normally I shoot with the Muted setting with toning turned off, by default toning is turned on and set to red. I could re-shoot those again at macro, however many of my macro shots are sharper, It is the distant shots that suffer. A good example is Pine trees. At 500 ft the needles are all a mess and almost not distinguishable, this happens with the sigma, the pentax 28-80, and the pentax M 75-150. With all 3 lenses distant detail is lost. Shots done at 100ft are not so bad, but still not as focused as I would expect considering how well it does close up.
Not being savy I am not sure what m=0.5 means. Sorry for my ignorance on the technical side.

DeWolf
01-18-2014, 08:13 PM   #19
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m=0.5 means magnification of 0.5 =1/2 = 1:2. i.e., the scene you shot is 1/2 it's actual size on the sensor. Well anyway, assuming you were focused on the 13 the focus is likely OK. But the lens is very low in contrast/unsharp. Not really acceptable IMO. But that was your conclusion also.

But about the distance shots--are you using manual focus (MF) or is it AF? If it was AF do it carefully w/ manual focus. (Now that you see the lens screen/manual focus is OK) this is the 2nd step in figuring out what is wrong.

Basically the lenses should do better at a far distance, than very close. Some lenses do somewhat better at moderate distance, but generally best at far distances. If the manual focus shots are good (at distance) then it means the AF needs to be adjusted for each of your lenses. If it is not OK (not sharp) w/ manual focus, that means the lens(es) are unsatisfactory for your purpose.

01-18-2014, 08:28 PM   #20
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One other thing--if the lens is wide open at f/5.6, you would not expect it to be very sharp there. However, at f/11 (or possibly f/16) it should be the sharpest. And then at f/22 it will not be sharp.
01-18-2014, 08:28 PM   #21
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QuoteOriginally posted by dms Quote
m=0.5 means magnification of 0.5 =1/2 = 1:2. i.e., the scene you shot is 1/2 it's actual size on the sensor. Well anyway, assuming you were focused on the 13 the focus is likely OK. But the lens is very low in contrast/unsharp. Not really acceptable IMO. But that was your conclusion also.

But about the distance shots--are you using manual focus (MF) or is it AF? If it was AF do it carefully w/ manual focus. (Now that you see the lens screen/manual focus is OK) this is the 2nd step in figuring out what is wrong.

Basically the lenses should do better at a far distance, than very close. Some lenses do somewhat better at moderate distance, but generally best at far distances. If the manual focus shots are good (at distance) then it means the AF needs to be adjusted for each of your lenses. If it is not OK (not sharp) w/ manual focus, that means the lens(es) are unsatisfactory for your purpose.
understood, I have used both with AF and MF, both looked sharp in viewfinder, but not in actual image.
The other 2 pentax lenses, are the same as far as detail in distance. more a lack of definition.

I guess a better lens is in order then.

DeWolf
01-18-2014, 08:39 PM   #22
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To be sure--when you manually focus and then take the picture--it is not sharp? And this is with the lens set at f/11 of f/16? If that is the case, then yes I think a better lens is your next step.
01-18-2014, 08:47 PM   #23
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yes, manual focus, sharp in the viewfinder, soft in the image. the sweet spot on this lens seems to be F8. It is rare I have enough light for F16, but F11 is doable if i relent to 800 ISO.

DeWolf

01-18-2014, 09:17 PM   #24
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I suggest you use iso 1600 and try to use f/11 or f/16. And turn off noise reduction, as it kills the sharpness. A little noise does not detract from a good picture. Look at the pictures at a reasonable size on your monitor (ideally well below 100%, and certainly not above 100%). If the lens is not usable at that condition or you really want to be able to use f5.6 and lower iso, then consider a new lens. Not much more I can say. Good luck.
01-18-2014, 11:01 PM   #25
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QuoteOriginally posted by dewolf Quote
read the reviews on the DA*60-250, and certainly seems like the best option for me. Question is, will the internal motor work on the K-30, or will it revert to the cameras focus motor?

DeWolf
Yes the K30 has SDM contacts for SDM autofocus motors

I've been very happy with the DA 55-300 WR, and at your budget you could get another lens also, maybe something wide angle
01-19-2014, 05:28 AM   #26
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QuoteOriginally posted by dms Quote
I suggest you use iso 1600 and try to use f/11 or f/16. And turn off noise reduction, as it kills the sharpness. A little noise does not detract from a good picture. Look at the pictures at a reasonable size on your monitor (ideally well below 100%, and certainly not above 100%). If the lens is not usable at that condition or you really want to be able to use f5.6 and lower iso, then consider a new lens. Not much more I can say. Good luck.
Thanks for all your help by the way, quite informative. ISO 800 is pretty nasty on this camera unless in bright light. I will try turning off the noise reduction. I thought the noise reduction settings only applied to JPG format. I always shoot raw.

Thanks again.

DeWolf
01-19-2014, 05:30 AM   #27
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QuoteOriginally posted by ToyTank Quote
Yes the K30 has SDM contacts for SDM autofocus motors

I've been very happy with the DA 55-300 WR, and at your budget you could get another lens also, maybe something wide angle
Good to know, I had found other Sigmas with motors for other camera brands, but the motor was removed for the Pentax version.
I will be looking into both the 300 and 250 Pentax lenses.
Thanks
01-19-2014, 08:30 AM   #28
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QuoteOriginally posted by dewolf Quote
ISO 800 is pretty nasty on this camera unless in bright light.
ISO800 performance on that camera (K-30, right?) is among the best for any APS-C camera ever released by any manufacturer, FWIW. Whether best-in-class is 'good enough' or not is a matter of opinion of course so yours is as valid as anyone else's.

Personally I wouldn't call it 'nasty' but there certainly improvement by going to ISO100.
01-19-2014, 08:49 AM   #29
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QuoteOriginally posted by ElJamoquio Quote
ISO800 performance on that camera (K-30, right?) is among the best for any APS-C camera ever released by any manufacturer, FWIW. Whether best-in-class is 'good enough' or not is a matter of opinion of course so yours is as valid as anyone else's.

Personally I wouldn't call it 'nasty' but there certainly improvement by going to ISO100.
Speaking about the K5, with the same resolution sensor, I think you do lose a little more between 400 and 800 than between lower settings. For distant landscapes, at 800 you seem to lose some of the fine foliage definition that makes the picture look sharp, but 800 works for me for close-up images of a single leaf or flower, for example.

Up through 400 it seems the 16mp sensor holds up a little better than its 6 and 10mp predecessors, even at 100%. Since 100% is, by definition, more demanding as the mp increases, the 16mp sensor is actually quite a bit better than its predecessors when you compensate for how much more effective magnification you're viewing with.
01-19-2014, 12:41 PM   #30
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QuoteOriginally posted by tibbitts Quote
Speaking about the K5, with the same resolution sensor, I think you do lose a little more between 400 and 800 than between lower settings. For distant landscapes, at 800 you seem to lose some of the fine foliage definition that makes the picture look sharp, but 800 works for me for close-up images of a single leaf or flower, for example.

Up through 400 it seems the 16mp sensor holds up a little better than its 6 and 10mp predecessors, even at 100%. Since 100% is, by definition, more demanding as the mp increases, the 16mp sensor is actually quite a bit better than its predecessors when you compensate for how much more effective magnification you're viewing with.
I try to shoot below 640 ISO, granted that's not always possible. Birds in flight are the troublesome shots, the sky, for some reason, is always purple, but easily corrected, but the ISO noise in the sky can get pretty bad, and a problem when you want to remove it without losing the texture of feathers. I am using NeatImage for now. I have tried Noise Ninja, and for some shots it is much better. Photos with a lot of texture, ie city and woodlands, are usually fine with no noise reduction, as it gets hidden. For me, the sky is the biggest issue, and getting the faces of moving birds sharp, thats a bugger at best lol.

DeWolf
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