Crop Factor, Low Light and Aperture with m4/3 lenses? Part 2

Started Jun 16, 2014 | Discussions thread
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knickerhawk Veteran Member • Posts: 4,899
Re: Reply to Just another Canon shooter

Just another Canon shooter wrote:

knickerhawk wrote:

The nature of the noise (the "pattern") is a property of the spatial distribution, which is a completely different property. I was talking exactly about that.

While spatial distribution is a factor to consider when examining noise, it's not the only consideration.

It is, for me, which was the whole point I was trying to make. I was saying that the color pattern looks non Poisson to me.

Looks can be deceiving, especially when you don't know what to look for. That's where the std. dev. numbers can be helpful.

Does the crop on the lower right look NR'd to you or no? If it does, this is an indirect confirmation that the St.Dev. is not a good metric of what you see.

To sum up, the std. dev. measurements

Let me repeat that the St.Dev. cannot tell you anything at all about the character of the noise or even if it can be qualified as noise.

Nonsense. The Std. Dev., especially when broken out in LAB tells you a lot about the character of the noise for what is ideally a uniform patch with 0 deviation. We do not disagree that the number tells you nothing about the spatial distribution of the noise, but spatial distribution is only one element of noise.

and my own two eyes confirm that the character of the noise (the look) is different between these two cameras and the two converters but that's hardly a surprise and certainly not evidence that Adobe is somehow inappropriately tipping the scales in favor of the Oly (and only the Oly) with respect to noise reduction. Your speculation on that point is meritless.

I did not say "inappropriately". And you did not answer the question, which was very simple. Does the lower right square look more NR'd than the rest or no? As simple as that.

I answered your question in detail. It's just that my answer wasn't the admission you were looking for. To repeat, there is less luminance variation in the LR Oly patch but more color variation relative to the DXO Oly patch. The spatial distribution and color "pattern" you keep referring to is very similar between the two patches. This conclusion is supported by the Std. Dev. numbers and examination of the individual channels for the two patches in LAB. Your characterization that LR "clearly...applies more NR (or whatever you want to call it to the color to the Oly than DXO" actually has things turned around. The character of the noise is more luminance influenced in the DXO rendering and more color influenced in the LR rendering. The opposite of what you claimed. Unfortunately, your refusal to utilize readily available objective information to enhance your initial subjective impression (which is apparently weighted strongly toward better discrimination of luminance differences than to color differences) has biased your observational skills.

By the way, according to DXO, the red channel is the least sensitive for both the 6D and the EM1.

What we see depends on the three RAW channels, on the values of the color matrix, etc. Canon's blue color filters tend to be not so "pure".

You said, "[Blue] is the noisiest color for the 6D." Now that seems to be evolving to "not so pure" whatever that means.

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