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Author Topic: On Landscape Review the Canon 5DS/R  (Read 12470 times)

timparkin

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Re: On Landscape Review the Canon 5DS/R
« Reply #20 on: July 20, 2015, 08:32:56 am »

I haven't actually reproduced any classical MTF curves. I've only put up curves for the resolution calculated and 5% and 9% contrast. I have included one resolution versus contrast curve but I have explained why you get resolution above nyquist (and it's nothing to do with aliasing!).
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timparkin

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Re: On Landscape Review the Canon 5DS/R
« Reply #21 on: July 20, 2015, 08:34:53 am »

The sharpening was applied as a 'proof' there was detail still available, not to show some absolute value of increased resolution due to sharpening (which I agree would be pointless). The test was just to show that sharpening increase contrast at the pixel level, which it does. The absolute values don't really matter. If the MTF5 was below nyquist then sharpening is unlikely to improve it.

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timparkin

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Re: On Landscape Review the Canon 5DS/R
« Reply #22 on: July 20, 2015, 08:35:52 am »

Which is why we did a lot of test on real world images at comparable sharpening levels to prove that it worked in the real world..
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timparkin

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Re: On Landscape Review the Canon 5DS/R
« Reply #23 on: July 20, 2015, 08:39:10 am »

Hi,

With sharpening we get some egocentric MTF. This would essentially be OK and perhaps even relevant if there was a standard sharpening. So, it may be best to use like DCraw to decode the raw files.

I recall that Jim Kasson was doing some testing and found that the Sony he was using produced better MTF at large apertures than the Nikon. Stopped down they were pretty close. What Jim found out that although sharpening set to zero, LR was still applying significant sharpening, and that differed between the Nikon and the Sony. On the Nikon EXIF detected the lens in use. The adapter on the Sony gave no information on the lens. So, on Nikon LR had little sharpening as it knew that the Otus was very sharp, with the dumb adapter on the Sony LS assumed a mediocre lens and applied more sharpening.

Talking to all you gentlemen  gives great insights in weaknesses of testings and turn opinions into humble opinions. IMHO, that is.

Best regards
Erik


Perhaps you should ask first before commenting on the weakness of the test :-) We used dcraw for the test raw conversions for all examples.. Lightroom sharpening was used on top of dcraw demosaicing because Lightroom seems to be what most people are using. Finally we use these levels of sharpening on real world images.
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timparkin

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Re: On Landscape Review the Canon 5DS/R
« Reply #24 on: July 20, 2015, 08:41:37 am »

I found that last statement in the conclusion to be quite an underhanded swipe at MF. "Price" Canon Wins, "Usability" Canon Wins. Performance "?"

But the biggest take away IMO was the performance of the new range of Canon lenses. Superb.

I would have thought the fact we're talking about a 'completely different ballgame' would imply vast differences.

And yes for Price and Usability Canon wins and obviously on Performance MF wins (at least the highest end MF).

How is this a swipe at MF? Do you disagree?
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