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10-30-2008, 05:29 AM   #1
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off-topic ("just")

Canon EOS 50D Review: 31. Conclusion: Digital Photography Review

On the one hand, I try not to care about either competing reviews or about the whole K10D "just" brohaha. On the other hand, I can't help but grin.

10-30-2008, 06:09 AM   #2
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Eos50D versus K20D conclusions

And here's the their conclusion for K20D:

Pentax K20D Review: 34. Conclusion: Digital Photography Review

You right dpreview likes K20D more as its highly recommended yet they have cons to say about it too.



QuoteOriginally posted by mattdm Quote
Canon EOS 50D Review: 31. Conclusion: Digital Photography Review

On the one hand, I try not to care about either competing reviews or about the whole K10D "just" brohaha. On the other hand, I can't help but grin.
10-30-2008, 06:19 AM   #3
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On Topic

QuoteOriginally posted by mattdm Quote
Canon EOS 50D Review: 31. Conclusion: Digital Photography Review

On the one hand, I try not to care about either competing reviews or about the whole K10D "just" brohaha. On the other hand, I can't help but grin.
It JUST tells that no one can make a better DSLR but JUST a worse one in APS-C format with a pixel density of around 15MP.
10-30-2008, 06:30 AM   #4
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Original Poster
from the 50D review, on the K20D

Comments from the review on the K20D:

Canon EOS 50D Review: 24. Compared to (JPEG): Digital Photography Review
QuoteOriginally posted by dpreview jpeg comparsion:
Despite the fact that the nominal resolution of these two cameras is very similar their output has quite different characteristics. While the amount of resolved detail is broadly comparable, the K20D image looks much more processed, with stronger sharpening and contrast and more accentuated colors - though it also has a touch more detail too. While Pentax' approach to processing certainly has more 'consumer appeal' the Canon output gives you more latitude in post processing.
Ironic, of course, given that the K20D's defaults are tuned this way largely in response to reviewers not liking the K10D's less-processed defaults. Can't win.

Canon EOS 50D Review: 28. Compared to (RAW): Digital Photography Review
QuoteOriginally posted by dpreview raw comparsion:
The EOS 50D and Pentax K20D offer nearly identical nominal resolution and after taking the in-camera processing out of the equation by shooting RAW there is not an awful lot between them. Having said that the Pentax image shows just a tad more detail, especially in crops close to the edge of the frame (coins on label, batteries). It becomes obvious that at 15.1 megapixels nominal resolution the 50D is limited by the performance of the lens while the Pentax prime lens is still capable of resolving the K20D's 14.6 megapixels.


10-30-2008, 06:38 AM   #5
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It is becoming very evident Samsung hit the sweet spot for an APS-C sensor for both resolution and noise. Add LV, a killer LCD, faster AF, and a low light assist lamp to the K20D for $1,200 and I'm back to a one camera system.

Ken
10-30-2008, 06:57 AM   #6
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QuoteOriginally posted by RiceHigh Quote
It JUST tells that no one can make a better DSLR but JUST a worse one in APS-C format with a pixel density of around 15MP.
Still stuck on pixel density.. Obviously mavericks can't read (or since their maverics refuse to read and believe)...... Give it up. Pixel density increase is a good thing.
DP Review's "belief" in pixel density problems is a myth...

Think you should read this thread and learn what pixel density really means.. Be sure to follow all the links.
Pixel density revisited: News Discussion Forum: Digital Photography Review
As for the evidence, Emil (http://theory.uchicago.edu/~ejm/) has pointed you to a post of his, there's a long series of posts which you didn't follow, but did discuss and present the evidence in some detail, there's John Sheehy's demonstration under the title 'the joy of pixel density' , and finally there have been extensive discussions of the physics behind it, which back up the position that in theory there is no causal link between pixel density and final image noise content at any given image size (with the caveat that there are noise effects such as random telegraph noise, which come into play at very small geometries). These discussions included a number of people who are research physicists (not me, I hasten to add), and included Eric Fossum.
Your urban legends are showing again.
Re: No really, it isn't: News Discussion Forum: Digital Photography Review
When one does this exercise, it becomes apparent that the main factor in image noise is sensor size. The result is largely independent of MP count for a fixed sensor size. Pixel density, which is sensor area divided by MP count, is poorly correlated to noise because both MP count and sensor size will vary from camera to camera, but only one of those factors is tied to noise level.
Read carefully and you may yet learn weedhopper......
https://www.pentaxforums.com/forums/pentax-dslr-discussion/40091-could-someon...vantage-2.html

Last edited by jeffkrol; 10-30-2008 at 07:16 AM.
10-30-2008, 01:28 PM   #7
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Jeff, I believe part of the problem here is that DPR is still measuring noise-per-pixel in its 100% crops, in which case any sensor with a greater pixel density and the same sensor tech will show greater noise, noise being a function of sensor area, because they're constantly looking at smaller and smaller areas in their crops.
10-31-2008, 12:41 AM   #8
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Maybe it's the end of the "add 2mpx on the sensor and 0.5 inches on the LCD and say it's brand new" era

10-31-2008, 04:45 AM   #9
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As long as manufacturing costs keep coming down, they'll keep adding megapixels, and maybe people will start to realize why that's not a bad thing, and maybe dpreview will learn not to base conclusions about the viability of higher pixel densities on a single camera.
10-31-2008, 04:50 AM   #10
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Samsung definitely hit the sweet spot. I am amazed that Canon has lost it's lead in low noise specs.

Ben
10-31-2008, 05:02 AM   #11
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Lucky that I did not put my money on 50D...

Surely this is a first though
10-31-2008, 08:25 AM   #12
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Well, I understand from this that many pixels means more diffraction and therefore less lens aperture usable (no well usable f:11, maybe in future not even f:8 ) Diffraction Limited Photography: Pixel Size, Aperture and Airy Disks . Check out the calculator and the sample with a 8Mpx sensor
Why the same lens 70-200 VR f:2.8 from Nikon produces a worst image on a crop camera sensor than on a FF camera
dpreview.com - Lens Review - Fullscreen
Both cases : 12 MPX but at higher f numbers the D300 is less good than D3 . Why is that ?
Thank you.

PS. More, remember that the cop camera uses more the center of the lens no the entire surface like the FF one (therefore vignette is more present).
10-31-2008, 01:11 PM   #13
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Diffraction and pixel density are a bit misunderstood. Diffraction is a property of the lens, unrelated to pixel density. Any lens is sharper at wider apertures than at extremely small apertures, that's what diffraction does. Sensors with higher pixel counts are able to display that effect at smaller apertures. On a 6mp sensor you might not see the effects of diffraction until f16, but the effects are still happening. The sensor just doesn't have enough resolution to show the difference. By contrast, a 14mp sensor might show diffraction at f8. This doesn't mean that you'll start seeing worse performance from the 14mp sensor than the 6mp sensor between f8 and f16; it's just that the 14mp sensor is outresolving the lens at that point. At f16 you'll get the same resolution you would have gotten with the 6mp sensor, but again, that's a limit of the lens, not caused by the pixel density. So really, you're not losing anything due to diffraction with higher pixel densities, but you're certainly gaining resolution when you have the lens on a wider aperture.
10-31-2008, 04:13 PM   #14
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Yes, but it's more a physics law than a lens problem (or both in the same time). An expensive and/or a cheap lens will have the same diffraction problem at less wide apertures and makes the sensor less usable, at least at the marketed resolution . This means a more expensive lens can not resolve anything in this matter. So, what's the point in having more pixels (meanig more money to spend) and less apertures available at the theoretical sensor's resolution. In that case presented with the same Nikon lens on different Nikon bodies and same resolution but different pixel density, why the results are not in the favor of the D300 regarding the resolution ? I think the solution is a bigger sensor or not to increase the crop sensor's resolution (meaning less pixel density) which already is high (maybe too high). On film one can use apertures from the widest to f:16 without much problem , if any. So you have a wider range of apertures to select from meaning also more creativity. The 4/3 system is even worst in this concern , having a sensor surface of about a quarter of the 35mm film frame.
10-31-2008, 11:54 PM   #15
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As you stated, it's a physics problem. And the laws of physics don't change for pixel density.

The point in having more pixels is so that we can fully use the resolution of the lenses at any aperture. The difference in the case you provided between the D300 and the similar-resolution full-frames is due to the fact that the lens doesn't have to work as hard to resolve for the same field of view. The lens on the full-frame sensor simply doesn't have to resolve as much, so the softening effects of diffraction don't show up until even smaller apertures are reached. This is a function of sensor size, not pixel density. So you're right in thinking that a larger sensor would be beneficial in this case, it's just that pixel density doesn't have much to do with it. Diffraction effects were perfectly visible with film as well, but it's worth remembering that popular film formats started at 35mm and went up from there, so the effects of diffraction would be seen even less, again as a result of format size and the demands placed on the lens by each.
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