Pixel Density is GENIUS!

Started Jul 13, 2008 | Discussions thread
John Sheehy Forum Pro • Posts: 21,743
Re: No really, it isn't

RRJackson wrote:

Roland Karlsson wrote:

Sure - the optics is a part of the equation. But - it does not add
noise - just unsharpness.

Sure, but part of his presentation concerned the overall image
quality and he talked a bit in his post about the sharpness of the
image.

Exactly how sharp do you think anti-aliased pixels from the sharpest lens could be at 289%?

Part of the problem with demonstrations such as mine is that I am assuming a base level of knowledge of what the givens are in RAW imaging, a base knowledge that the vast majority of readers lack. RAW data is VERY simple, but it is different, and you need to get used to the differences.

Of course, the noise is another issue that really needs to be
tested using color charts as well as some real three-dimensional
targets under several temperatures of lighting at a variety of
contrast levels to see what's really happening and when.

Again, the RAW data is very simple. Barring unequal noise reduction, there is no way the ratio of noise between these two images can change with any homogeneous change of subject, white balance, contrast, etc, as they are both completely in the read-noise dominated tonal ranges.

I could do a color checker, but color checkers are suspect, because they contain no detail, so noise reduction is easy to hide, as well as the effects of sharpening or blurring, especially with the existence of edge-preserving algorithms. That's why I prefer doing scenes with some detail when comparing two cameras or pixel density's performance. If you sharpen or blur, it's easier to see, and the detail vs noise varies somewhat together.

These two cameras clearly have almost exactly the same color response, so barring IR or UV influence, change of light source is only going to change the two images in tandem.

The idea of testing

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John

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