misunderstandings...

[Audionut]

You want to discredit me somehow, but you are to lazy to explain yourself or you actually don't know what you are talking about. Either way, I challenge you. Explain yourself or be quiet about it.

It was a simple question.

http://www.nikonusa.com/en/Learn-And-Explore/Article/gy43mjgu/moir%C3%A9-false-color.html

In many D-SLRs an OLPF—also known as an anti-aliasing filter—prevents false color and moiré that can ruin a picture. The trade-off to using an OLPF is slight softening of the image. To counteract the softness, in-camera sharpening is used and can be further adjusted by the end user. In addition, photographers who shoot the NEF (Nikon Electronic File) RAW file format can add more sharpening in post-production.

Do you have hard evidence to to describe the amount of in-camera sharpening applied on the cameras in question?

I will even give you a hint. DXO's sharpness test are just another way of presenting the same data that has always been used to express the resolution of an optical system. Go ahead and make my day.

Sharpness

Sharpness is a subjective quality attribute of an image or a lens. Sharpness indicates the visually perceived quality of details of an image or details reproduced by a lens. It is associated with both resolution and contrast of reproduced details (within an image or by a lens).

The DxOMark score for Sharpness is based on the Perceptual Megapixel (P-Mpix) concept that weights the Modulation Transfer Function (MTF) of the lens with the human visual acuity. Read more about Perceptual Megapixels.

I question DxO marks measure of sharpness, as a valid indicator, of the performance of an OLPF.  Subjective measurements are not necessarily accurate.


Now I challenge you.  Lose the smug arrogant trolling attitude, or go away.  Your choice!

[eoshq]

What I said from the very beginning was that the 5D3 does not have a stronger OLPF than the 5D2 and  I want people to stop saying that it does, because that simply is not true. And it certainly is not the reason that it does not suffer from moire and aliasing as much as many other DSLR's.

I used DXO's testing as one example of solid, scientific evidence about the 5D3's OLPF. What DXO is testing is the combined MTF performance of a lens and camera together as an optical system. They present it as Perceptual Megapixel (P-Mpix) and call it sharpness to be easier for most people to understand. They really should call that score resolution because that is what they are measuring. When they say that the 5D3 achieves 18 P-Mpix with the 40mm f/2.8 and the 5D2 achieves 15 P-Mpix with that same lens, they are just saying that the 5D3 reaches a higher MTF score.

"The Perceptual MegaPixel (P-MPix) is a proprietary ranking of lens-camera combinations, created by DxO Labs. It is intended to express the resolution a camera produces when paired to a particular lens."

DXO has tested 108 lenses on the 5D3 and 5D2. In every case, the 5D3 reaches a higher score. And this increased resolution can be also seen when comparing images in print or on screen. Full stop, that should be the end of the discussion about the relative OLPF strength of these two cameras. What more evidence is needed?

But wait, there is more:

We know that the 5D3 does not have any change in its optical system or sensor between still photo and video modes. There is no magical OLPF that moves in and out from the in front of the sensor.

We know from the folks at VAF who make addon OLPF's specifically to reduce alaising and moire of the 5D2 and other cameras in video mode, that these filters utterly destroy the full resolution image and must be removed for photography.

We know that early on a few people removed the OLPF filter from the 5D3 in hope that it would increase video resolution and this did not work. If they had thought to compare full resolution still images with the 5D2 beforehand they would have known this would not work.

We know that the 5D3 in raw video mode has increased resolution, again with no change in the optical system.

We know that the 5D3's full resolution is 5760x3840 or 5760x3240 in 16:9 ratio for a good reason. That reason can simply be expressed as 5760/3=1920, 3240/3=1080

We can speculate about the video processing inside the 5D3 that creates h.264 and why it is not as sharp as we would like, but I would guess that the reason is a lack of processing power and concerns with heat dissipation.

[Audionut]

I agree that your analysis seems solid.  However, you cannot conclusively say that the filter is stronger, weaker, or the same, based on a subjective measurement.  You can advise that the results suggest something, but you cannot be adamant.

You should consider this before accusing others of spreading BS, or otherwise expressing any opinion, that differs from yours.

Attack the post, not the poster. 

[eoshq]

Thank you. I tried to make my analysis in an objective manner. I am basing my conclusions on actual MTF measurements made by DXO and my own analysis of images taken with both cameras in fully controlled tests.

Food for thought:
1. Both the A7R and D800 achieve maximum DXO P-Mpix scores of 29 megapixels even though they are 36 megapixel cameras. With each camera that score is only with one exceptional lens. The vast majority score much lower. Could it be that somewhere around 30 megapixels is the maximum usable resolution of a 24x36mm sensor and only with a nearly perfect lens? Why is it that lower megapixel cameras such as the D600 and 5D3 can achieve scores much closer to their full resolution?

2. Canon has made decent gains in resolution over the last few years even with zero or very small increases in megapixels. Witness the 1D-X, 5D3 and 6D's gains over the previous generation 1DMIV, 1DsMIII and 5D2 as well as the increases of the 70D/700D/100D over the 7D. What is Canon doing differently now with their sensors versus a few years ago?

[eoshq]

I am not good at being diplomatic but really all I wanted to do is give the information that I had found. Thank you for listening and for your contributions to the Magic Lantern and DSLR video communities.

[ted ramasola]

I concede that my previous observations regarding the behavior of the 5d mkIIIs image may have contained invalid conclusions.

eoshq's analysis on the image quality contains some important information that has provided me with better understanding.

[Audionut]

Could it be that somewhere around 30 megapixels is the maximum usable resolution of a 24x36mm sensor and only with a nearly perfect lens? Why is it that lower megapixel cameras such as the D600 and 5D3 can achieve scores much closer to their full resolution?

Pixel size is something that immediately springs to mind.  I would assume that smaller pixels can capture smaller detail.
There's obviously a defined limit, based on the sensor size.  No idea what that is.

2. Canon has made decent gains in resolution over the last few years even with zero or very small increases in megapixels. Witness the 1D-X, 5D3 and 6D's gains over the previous generation 1DMIV, 1DsMIII and 5D2 as well as the increases of the 70D/700D/100D over the 7D. What is Canon doing differently now with their sensors versus a few years ago?

Processing IMO.
Better processing could mean a reduction in sensor filtering, resulting in increased detail.

Everything is a game of pros vs cons.  IIRC, the new Sigma 50/1.4 could have had much greater sharpness, but the result was increased CA, and something else I cannot recall atm.  So they choose to reduce sharpness, for a better overall product.
I'll add a link when I find it.

Same with pixel size.  Smaller pixels may produce finer details, but they also capture less light.  When the manufacturers do away with antiquated RGB filtering, this won't be so much of a problem