Hi,
Do not misinterpret the numbers, and yes they need interpretation.
Color sensitivity as measured by DxOmark, is very much signal to noise ratio and dynamic range driven. And we know that Canon sensors are not leading in that aspect. Also, the small photosites of the 5DS with their smaller 'well depth' or storage capacity will have a harder time to collect many photons. But they compensate for their small size by their large number of photosites per unit area.
Now look at the Sensitivity metamerism index (ISO 17321): 5d Mark III was 74 / 75 (for CIE-D50 / CIE-A), the 5DS is 82 / 71, and e.g. the D810 is 80 / 78. So the Daylight metamerism index has improved significantly over its predecessor.
Cheers,
Bart
It's really strange, though. The
5DsR has the exact same metamerism results as the 5D3: 74/75 (CIE-50/CIE-A). But the
5Ds is much better for daylight at 82/71, which is close to the improvement I was hoping for.
How can this be?
Did Canon tweak the 5DsR for artificial light and the 5Ds for daylight, without telling us?Or did DxO have a bad copy of one of the cameras, or made an error?
There are
three theories I've been considering.
The first is that Canon has
weakened the CFAs on their latest cameras to let more light in to get lower noise at high ISOs, compromising accurate color to do so. But Canon doesn't let on what they are doing. The metamerism scores seem to be the best indicator. The 5Ds/5DsR was rumored to have stronger CFAs.
The second is that Canon has been
tweaking the color filter arrays (CFAs) to perform better in artificial light, which has compromised daylight color.
The third is that they're tweaking the CFAs
to get "more pleasing" caucasian skin tone colors.
I'm not happy with the third theory, because I mainly shoot landscape, but that's may be unchangeable. But what about the first two? I was hoping the 5DsR would again give more accurate daylight color, like the 1Ds3 is known for, having a 86 daylight metamerism score. It's artificial light score was a really high 80 too, though.
Nikon used the same AA filter cancellation method in the D800/D800E, but DxO's metamerism scores were only 1 point different. So the AA filter can't be causing this huge metamerism score difference in these new 5Ds cameras.
Canon has been totally silent about what they've been doing to color, so I wouldn't expect them to announce color changes to these cameras (though, it would be very helpful). But why would the AA version have better daylight results than the cancelled AA version?
No one seems to have the answer at DPR or FM, so I thought I'd ask here. This is so strange to have the exact same metamerism score as the 5D3 in just one of these cameras.
The 5D3 seems to be prone to have too much purple, for example, perhaps to make up for the lack of purple in artificial light, I'm guessing.
It's so hard to figure this out, because hardly anyone has been addressing the topic of what Canon has been doing to color.
Back
in the film days, it seemed that
everyone talked about color, and knew what each film did.
But now that the camera companies are dialing in color characteristics into the hardware, there hasn't been much discussion at all. But lots of talk about DR, sharpness and ISO noise. But color isn't any less important.
A similar thing has happened in HiFi audio, in which the 'magic' is mostly now gone, to make components and audio files that are "good enough" instead of excellent and breathtaking.
This is my first post here, but I've been reading the LL forums for many years, and I've found some of your posts fascinating, Bart! Thank you, very much!
