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04-26-2011, 03:48 PM   #106
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Sharpness issue? ha!



04-26-2011, 07:55 PM   #107
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I've been through each page of this thread and I have not seen an objective definition of sharp. It reminds me of employees in an office arguing over whether it is hot or cold in the office with nary a thermometer in sight. I believe that an objective, concise, jargon-free definition of sharp is the only way to meaningfully discuss whether or not a photo is, in fact, sharp. Otherwise, it's all just noise and feelings. It's fine to have both a subjective and objective definition, but objective seems to be what is lacking.

I don't feel qualified to offer a definition myself. Any takers?
04-26-2011, 08:49 PM - 1 Like   #108
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QuoteOriginally posted by Designosophy Quote
I've been through each page of this thread and I have not seen an objective definition of sharp. It reminds me of employees in an office arguing over whether it is hot or cold in the office with nary a thermometer in sight. I believe that an objective, concise, jargon-free definition of sharp is the only way to meaningfully discuss whether or not a photo is, in fact, sharp. Otherwise, it's all just noise and feelings. It's fine to have both a subjective and objective definition, but objective seems to be what is lacking.

I don't feel qualified to offer a definition myself. Any takers?
I'm going to give it a try.

And I want to state(on record) that I can't so much as EXPLAIN what it is as I can identify what it is. And here's how that works...
When I take a camera in the studio, I have familiar expectations of what good images are and should look like at 1:1
In fact... everything relative to sensor performance/sharpness is founded on the condition of the pixel quality. What is that you may ask?
Well... a good image is an image that translates to clear and accurate pixels in processing with as little distortion as possible.

One example of this is where an image proves to sharpen well in contrast to a poor quality image. This translates to little or no distortion around specified areas such as patterns and/or colors that are usually subject to distortion(ie. high contrast edges sharing similar colors etc etc).

Another good example of image quality can be found in the grain or noise patterns. And though most controlled images are shot at low ISO, lets not kid ourselves into thinking they are noise free! And so this plays a major part in the overall IQ of an image as well. Because "everything" and I mean everything, counts when we get to the development of our images.

My last and final attribute with regards to image quality and sharpness is as much a controversial one as it is a relative one. And that's where the image is balanced between pixel sharpness and accuracy. One good example of this can be found when comparing D7000 RAW images with the Pentax K-5. Which at first glance may seem sharper(at the pixel level) than the K-5(true story). However, the D7K will introduce artifacts far sooner than its K-5 counterpart insofar as edge masking goes.
In fact, in many of the RAW files, I've found the D7K images already contained edge artifacts whereas the K-5 did not. Now this may not bother the casual shooter as were talking on a 200% canvas. However... when we get down to processing, it matters.

Likewise... the trade-off the D7K makes in pixel sharpness comes at the expense of moire artifacts which are very difficult(if not impossible) to deal with.
And in many cases, not worth the trade-off. (see: AA filter etc). And so for me, the term sharpness is a term I use to define how well an image responds to detail and color extraction(fidelity). So in short, I'd say it all comes down to how well the files respond to processing. Or the initial quality and fidelity of the RAW files.

PS. if you really want to get your hands dirty on what good quality files can do. Try downloading some RAW images from the 645D and compare them to the K-5 in terms of push processing. The detail one can extract from a 645D RAW file is nothing short of staggering. And by detail, I don't mean in resolution(that's expected). What I'm refering too is the amount of sharpening one can apply to the image before it begins to produce artifacts.

Hope this helps.

Last edited by JohnBee; 04-26-2011 at 09:02 PM.
04-26-2011, 11:31 PM   #109
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Here's Mine

04-26-2011, 11:54 PM   #110
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how soft?.......K5 and Sigma 28-70 EX
04-27-2011, 02:09 PM - 1 Like   #111
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QuoteOriginally posted by Designosophy Quote
I've been through each page of this thread and I have not seen an objective definition of sharp. It reminds me of employees in an office arguing over whether it is hot or cold in the office with nary a thermometer in sight. I believe that an objective, concise, jargon-free definition of sharp is the only way to meaningfully discuss whether or not a photo is, in fact, sharp. Otherwise, it's all just noise and feelings. It's fine to have both a subjective and objective definition, but objective seems to be what is lacking.

I don't feel qualified to offer a definition myself. Any takers?
Here's my definition.

Do I like the shot? Is the detail there that I like to see? If the answer is yes, then it's acceptably sharp to me.

I'm not really kidding. Debates like this are like debating the number of angels that can dance on a pin head. Either the K5 (or any camera) is sharp enough for you, or it isn't. I don't really care what the "numbers" say as long as I like it.

IMHO, pretty much any camera these days will meet my definition, so I look for other features, like high ISO, ergonomics, SR, etc. Image quality is way down the list for me because I haven't seen a camera that doesn't have basically good image quality in the last several years. There are differences, but nothing that I'd consider a slam-dunk absolute of one over the other.

Of course, this being a gear forum, I understand the desire for a number. I'm an engineer myself, so I can appreciate the desire. I just don't necessarily agree with it.

(end rant)
04-27-2011, 04:40 PM   #112
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This one is not fair.......everyone knows Otis is always one sharp Squirrel.......
[IMG] [/IMG]

Tungsten light overhead, no flash ISO 1600
[IMG] [/IMG]
04-27-2011, 05:13 PM   #113
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QuoteOriginally posted by Couscousdelight Quote
Here are some shot i've made these last 2 weeks.
The sharpness of that dandelion pic just sliced my eyeballs.

04-27-2011, 06:03 PM   #114
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From the images posted, I see a whole lot of sharpening done during post processing... which is to be expected. That in itself muddies the waters somewhat trying to prove that the K-5's sensor isn't soft.

From my experience, there are so many variables why an image may not appear tack sharp: crappy filter, crappy lens, subject or camera movement, poor technique in holding the camera steady, jabbing the shutter button, mis-focusing, user error, etc.

Assertions about the K-5's sensor's supposed softness is pretty weak imo based on the many images that I've personally taken. Having said that, most people are probably unaware that images straight from the camera do require post processing. These can and often should be sharpened prior to processing and certainly just before final image rendering. Nik Software's Sharpener Pro 3.0 allows that option.
04-27-2011, 06:56 PM   #115
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QuoteOriginally posted by creampuff Quote
From the images posted, I see a whole lot of sharpening done during post processing... which is to be expected. That in itself muddies the waters somewhat trying to prove that the K-5's sensor isn't soft.

From my experience, there are so many variables why an image may not appear tack sharp: crappy filter, crappy lens, subject or camera movement, poor technique in holding the camera steady, jabbing the shutter button, mis-focusing, user error, etc.

Assertions about the K-5's sensor's supposed softness is pretty weak imo based on the many images that I've personally taken. Having said that, most people are probably unaware that images straight from the camera do require post processing. These can and often should be sharpened prior to processing and certainly just before final image rendering. Nik Software's Sharpener Pro 3.0 allows that option.
But isn't some degree of softness an inevitable consequence of an AA filter, which is needed to minimize artifacts, such as color moire? Fortunately, this softness can be corrected with digital sharpening techniques. The point is that one should not expect razor sharp images straight from the camera, unless one is willing to use one without an AA filter and then deal with the consequences of that. It's not for nothing that almost all manufacturers include AA filters in their cameras. There are exceptions, but they come at a price of occasional nasty artifacts.

The samples that are posted in this thread demonstrate that very sharp images can be gotten from the K-5, which is the point of the exercise. Some are clearly oversharpened, but others look fantastic.

Rob
04-27-2011, 07:16 PM   #116
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QuoteOriginally posted by Kenn100D Quote

Here's Mine
I'm not sure if this is a "sharp" example or a "not sharp" example.

To me, the boat looks soft, perhaps from a little FF based upon the way the water looks on the near side of the boat.

Ray
04-27-2011, 07:55 PM   #117
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I think no one questions that Otis is sharp? I know I won't be the one to tell him he isn't........

That aside, I expect to sharpen almost all of my shots, and have always assumed it is necessary to some degree in a DSLR for the stated reasons above. If they are decent shots to begin with, and they certainly are from the K5, then you get an image that will process and print very nicely.....which is the goal...right?
If a sensor is bad, no amount of sharpening will overcome the deficiency, but this is not a remote possibility with the K5, if you can produce, it can produce. If anything, it makes processing much easier than ever before from Raws...anyone else notice this?
Best Regards!
04-27-2011, 09:45 PM   #118
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I do not understand why there has to be a question over sharpness in this forum every time a new Pentax dSLR is released. Search for it and you'll see at least one rant about each camera having 'softness' issues. Being on my 6th different Pentax dSLR I have not experienced *any* image softness produced by any of these cameras that I cannot attribute to user error or lens limitation. Now, there may be bad copies of cameras with malaligned or defective sensors, or there may be bad lenses causing the unsharp images, but on the whole, the cameras are not the cause of unacceptably soft results.

Then there's how an image looks after processing from your own computer, and the way the image looks after being uploaded and manipulated (either by JPEG compression or resizing) by internet host sites (cf. Surfer - Pentax User Photo Gallery for my own example).
04-28-2011, 02:40 AM   #119
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QuoteOriginally posted by robgo2 Quote
But isn't some degree of softness an inevitable consequence of an AA filter, which is needed to minimize artifacts, such as color moire? Fortunately, this softness can be corrected with digital sharpening techniques. The point is that one should not expect razor sharp images straight from the camera, unless one is willing to use one without an AA filter and then deal with the consequences of that. It's not for nothing that almost all manufacturers include AA filters in their cameras. There are exceptions, but they come at a price of occasional nasty artifacts.

The samples that are posted in this thread demonstrate that very sharp images can be gotten from the K-5, which is the point of the exercise. Some are clearly oversharpened, but others look fantastic.

Rob
Well I've used DSLRs with different sensors, both CCD and CMOS and to be honest, I seriously can't validate the AA filter arguments based on the shots I've taken. So to me that discussion is more theoretical than practical. I've never experienced any so called sensor "softness" with any of my Pentax DSLRs, if there were any softness it was likely because I used a junk lens or a crap filter. Have to agree with Ash on this one... it is a non-issue as far as I'm concerned.
04-28-2011, 03:40 AM   #120
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You can get good sharp shots with the K-5

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