FZ200 Diffraction Limit - Panasonic Tech Service

Started Aug 27, 2013 | Discussions thread
Detail Man
Detail Man Forum Pro • Posts: 16,789
Re: Does the Panasonic FZ50 violate the laws of Physics ?

Stephen Barrett wrote:

Detail Man wrote:

Stephen Barrett wrote:

Something is wrong with my last post. The test result of 1.3 pixels per line-pair for the FZ50 doesn't make sense. Either the test is too good or I blundered in my calculation. Too bad i have to go out now. It's going to drive me nuts.

Two photosites cannot be enough - simply because of the spatial frequency spectrum of periodic line-pairs (a "square wave" containing higher order harmonics as well as a fundamental spatial frequency), the Shannon-Nyquist sampling theorem, and the random-phase of aligning projected periodic line-pairs onto an image-sensors array of photosite locations. It's that simple.

Thanks Detail Man.
That is the reason that I said something was wrong with my previous post.
The question is:
How can you explain J C Brown's and Cameralab's test results?
By my calculations in my previous post, they seem to be resolving above the Nyquist freqency.
Cameralabs claims a resolution of 2100 line pairs per picture height for the Panasonic FZ50. The sensor height has 2737 pixels ==> 1.3 pixels per line-pair, so how do they get that resolution? If you click on the Cameralabs link that I posted, you can see the evidence. Also J C Brown's test is similar, claiming slightly less resolution, corresponding to 1.5 pixels per line-pair. So, what is going on? Did I drop a factor of 2 somewhere? Or, does the Panasonic FZ50 sensor violate the laws of physics to get twice the resolution of the sensor in my Canon SX30?

Well, (somehwere) I recently posted that such numbers games were more a subjective and variable "art" than a science. Bear in mind that (in-camera, RAW, or post) processing (with Sharpening and NR) are also most frequently involved. All proprietary parameters and methods. No way to compare the processing-chains of any of the individual units tested. Completely muddy.

Jimmy publicly raised a prime example of the unreliability of such subjective "judgement calls" here:


If I recall correctly, there was zero response in return.

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