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12-18-2013, 10:40 PM   #31
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QuoteOriginally posted by normhead Quote
People tend to forget how much camera movement affects, sharpness. .
What about at a high shutter speed.? For example 1/1000 handheld and 1/1000 rock solid tripod 2s timer. Would there be a visible difference?

12-19-2013, 02:04 AM   #32
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QuoteOriginally posted by timo Quote
I find decentering more annoying than a lack of sharpness in general. Much more difficult to deal with, and more obvious. Doesn't seem to worry a lot of people, who concentrate on centre sharpness only.
Well, there is true decentering, which essentially means your lens is broken and should be serviced -- fairly rare -- and then there is field curvature, which is a natural property of most lenses. If you want a flat-field, stick to macro lenses or stop down enough to cover it. Full-frame lenses used on APS-C might also maintain sharpness more towards the corners. And as a very general observation, I think that might be a design preference between between German lenses and Japanese lenses -- Germans are more concerned with edge-to-edge sharpness whereas the Japanese seem to go for maximum center sharpness at the possible expense of the edges not measuring up to the center.
12-19-2013, 02:29 AM   #33
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QuoteOriginally posted by vonBaloney Quote
Well, there is true decentering, which essentially means your lens is broken and should be serviced -- fairly rare -- and then there is field curvature, which is a natural property of most lenses. If you want a flat-field, stick to macro lenses or stop down enough to cover it. Full-frame lenses used on APS-C might also maintain sharpness more towards the corners. And as a very general observation, I think that might be a design preference between between German lenses and Japanese lenses -- Germans are more concerned with edge-to-edge sharpness whereas the Japanese seem to go for maximum center sharpness at the possible expense of the edges not measuring up to the center.
Yes, I understand the difference. Unfortunately I have had three major decentering episodes: one factory-serviced 55-300, which Pentax declared within spec (it was unusable); one Sigma 17-70, which the distributors replaced without quibble; and a second-hand FA28, on which Keh gave me a refund. It does happen. Primes seem less susceptible. As you might expect. Field curvature is common, but at least it tends to be symmetrical.
12-19-2013, 03:08 AM   #34
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Turning off SR helps improve sharpness A LOT too. This is probably what causes most of the improvement when using the 2 second delay option; SR automatically disables then. It's for a good reason that they were able to use it to blur the moiré out of the K-3 images with it. When using very high shutter speeds it's safe to use SR though.

12-19-2013, 03:13 AM   #35
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QuoteOriginally posted by Clavius Quote
Turning off SR helps improve sharpness A LOT too. This is probably what causes most of the improvement when using the 2 second delay option; SR automatically disables then. It's for a good reason that they were able to use it to blur the moiré out of the K-3 images with it. When using very high shutter speeds it's safe to use SR though.
You must have extremely steady, tripod-like hands. In most cases SR is a plus for me when hand-holding at normalish shutter speeds and an absolute must at shutter speeds equal to the focal length or slower...
12-19-2013, 04:55 AM   #36
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QuoteOriginally posted by vonBaloney Quote
You must have extremely steady, tripod-like hands. In most cases SR is a plus for me when hand-holding at normalish shutter speeds and an absolute must at shutter speeds equal to the focal length or slower...
No, I just carry a tripod.
12-19-2013, 05:03 AM   #37
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QuoteOriginally posted by Clavius Quote
No, I just carry a tripod.
Well of course turning off SR when on a tripod improves sharpness as it is not designed to be on when mounted and ends up correcting phantom vibrations. The question is does it improve sharpness when hand-holding...and it definitely does. But I see what you really meant is "use a tripod for maximum sharpness". Fair enough.
12-19-2013, 07:43 AM   #38
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I'm finding at my age and hand-steadiness a monopod has become an essential shooting companion for anything other than snapshots - and for the snapshots I'm using the K-01 or Q anyway so lens sharpness is an infrequent consideration.

Sorta rules out street as a category though.

12-19-2013, 08:05 AM   #39
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QuoteOriginally posted by everydaylife Quote
What about at a high shutter speed.? For example 1/1000 handheld and 1/1000 rock solid tripod 2s timer. Would there be a visible difference?
Yes, at prints sized 11x14 and above critically, but still noticeable even up to that point.

QuoteOriginally posted by Clavius Quote
Turning off SR helps improve sharpness A LOT too. This is probably what causes most of the improvement when using the 2 second delay option; SR automatically disables then. It's for a good reason that they were able to use it to blur the moiré out of the K-3 images with it. When using very high shutter speeds it's safe to use SR though.
I actually find SR most useful at slow shutter speeds. But that's for candids etc. On a tripod your camera automatically turns off the SR when you set your camera to a 2 second delay, for good reason. However, when I'm using my ball head and don't have time to lock the tripod, for small birds etc. SR is still useful. On the other hand if you're panning SR will ruin you images.
12-19-2013, 09:32 AM   #40
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QuoteOriginally posted by everydaylife Quote
What about at a high shutter speed.? For example 1/1000 handheld and 1/1000 rock solid tripod 2s timer. Would there be a visible difference?
There can be in my hands, especially with a telephoto. I do a good bit of water bird shooting from a kayak. I initially figured I was pretty safe on bright sunny days with fast shutter speeds and f/8. Most of my shots were poor and the best were mediocre. A short, telescoping monopod that I could use from my sitting position instantly improved every shot, regardless of shutter speed.

Before replacing a lens you think isn't "sharp", mount it on a tripod and if you're using a UV filter, take it off. Also, use a lens hood. It can make a big difference in whether a shot appears sharp. Veiling flare is often confused with softness. We all hand hold our cameras most of the time but many of my shots that aren't as sharp as I like are usually my fault. I have quite a few lenses and many came in batches of camera gear I found a garage sales. Some are no-name cheapies with rather poor reputations but I have had some pretty good results from all of them once I learned where the sweet spot was and used them for the shots they handle best.
12-20-2013, 10:45 AM   #41
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QuoteOriginally posted by normhead Quote
Side by side, you can tell when an image has been corrected for CA or distortion.
I have never found that to be true (at least not with CA corrections in Lightroom). I cannot see any difference between an uncorrected and corrected image, even at 1:1 resolution. The Lightroom corrections are very good, and they don't have any visible side effects. I can't say the same for corrections of contrast. Contrast corrections mimic, but don't precisely duplicate, what you get in a lens with excellent microcontrast.
12-20-2013, 11:18 AM   #42
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QuoteOriginally posted by northcoastgreg Quote
I have never found that to be true (at least not with CA corrections in Lightroom). I cannot see any difference between an uncorrected and corrected image, even at 1:1 resolution. The Lightroom corrections are very good, and they don't have any visible side effects. I can't say the same for corrections of contrast. Contrast corrections mimic, but don't precisely duplicate, what you get in a lens with excellent microcontrast.
So I assume , that you have images taken with a corrected lens, right off the camera to share, and an another image, taken with a similar but less corrected lens, that needed correction, that has been corrected in light room to compare it with? And you found that the cheaper less corrected lens was made just a s good as the more expensive corrected lens by Light Room? I would be really interested in seeing that comparison.
12-20-2013, 11:45 AM   #43
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QuoteOriginally posted by normhead Quote
So I assume , that you have images taken with a corrected lens, right off the camera to share, and an another image, taken with a similar but less corrected lens, that needed correction, that has been corrected in light room to compare it with? And you found that the cheaper less corrected lens was made just a s good as the more expensive corrected lens by Light Room? I would be really interested in seeing that comparison.
Wouldn't you also need those files for your claim that one looks better than the other? (Or else upon what basis did you make it?) Wouldn't different lenses always be involved, making it a tricky and subjective claim either way?
12-20-2013, 12:40 PM   #44
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QuoteOriginally posted by vonBaloney Quote
Wouldn't you also need those files for your claim that one looks better than the other? (Or else upon what basis did you make it?) Wouldn't different lenses always be involved, making it a tricky and subjective claim either way?
I'm just trying to clarify how he came to the conclusion he did. From my perspective, maybe he's on to something. We all know a corrected lens will perform better than an uncorrected lens. That's why we pay the big bucks for the corrected one. Saying you don't need them and can do the same thing in Lightroom, to me , that's an extraordinary statement that would require proof to be believed.

And yes the proof would be fraught with dangers… but if you're going to make the claim, you need to support it, or at least have some reason for making it. I doubt that it's true because if for no other reason, in my experience more correction leads to higher resolution, and I doubt Lightroom can replace lost resolution. It would be very unlikely that someone would put the effort into doing a correction on a lens without putting some effort into making things superior all around. But practically all we want to know is what gives us an better image, a heavily corrected lens, or an uncorrected lens corrected in Lightroom. I'd certainly be interested in seeing an evaluation of that, despite the difference in lenses. Another usual feature of heavily corrected lenses is very smooth bokeh, so that brings up another point. Does the bokeh in the cheap lens, with Lightroom correction, match the bokeh in a corrected lens of simlar focal length?

I'm just trying to make this assertion into something that might be useful to me. As I said, it's an extraordinary claim.
12-20-2013, 01:18 PM   #45
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QuoteOriginally posted by normhead Quote
I'm just trying to clarify how he came to the conclusion he did. From my perspective, maybe he's on to something. We all know a corrected lens will perform better than an uncorrected lens. That's why we pay the big bucks for the corrected one. Saying you don't need them and can do the same thing in Lightroom, to me , that's an extraordinary statement that would require proof to be believed.

And yes the proof would be fraught with dangers… but if you're going to make the claim, you need to support it, or at least have some reason for making it. I doubt that it's true because if for no other reason, in my experience more correction leads to higher resolution, and I doubt Lightroom can replace lost resolution. It would be very unlikely that someone would put the effort into doing a correction on a lens without putting some effort into making things superior all around. But practically all we want to know is what gives us an better image, a heavily corrected lens, or an uncorrected lens corrected in Lightroom. I'd certainly be interested in seeing an evaluation of that, despite the difference in lenses. Another usual feature of heavily corrected lenses is very smooth bokeh, so that brings up another point. Does the bokeh in the cheap lens, with Lightroom correction, match the bokeh in a corrected lens of simlar focal length?

I'm just trying to make this assertion into something that might be useful to me. As I said, it's an extraordinary claim.
Yeah, but he was responding to your claim that side-by-side the image that comes from a lens the "did it right" rather than post-corrected will be better. So how did come to that conclusion? What side-by-side image files are you looking at? (Point being is although you have a different conclusion, you'd need the exact same set of evidence to show support for your assertion.)
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