X-trans… no actual advantages, a big pain.

Source: I develop raw processing software.

X-Trans has a color sampling pattern of 3x3 pixels instead of 2x2 for bayer. This means that color for X-Trans is sampled from a 50% larger area, which 1) reduces noise 2) makes noise look slightly "better" than bayer noise (according to many including me).

It also has a downside in that it reduces fine detail somewhat compared to Bayer. In practical terms it also has a downside in being less supported by software, maybe because raw processing software developers consider it a big pain. ;)

I'm happy they made X-trans also for the 40mpx, it should improve the details (which is a weak spot due to the 3x3) significantly and still maintain the benefits of a 50% larger color sampling area.

> This means that color for X-Trans is sampled from a 50% larger area, which 1) reduces noise 2) makes noise look slightly "better" than bayer noise

X-Trans has less color sampling per unit area, so you get more chroma noise.

So the demosaicing either gets lots of color artifacts, or it has lots of baked in chroma noise reduction.

On Bayer, you can simply choose a different demosaic method (IGV or LMMSE, for example), or apply additional chroma noise reduction, and the playing field is leveled noise-wise.

Have a look at the color patches on dpreview's studio shot comparison and compare any X-trans sensor with a bayer sensor with the same size and pixel count. Use RAW and high ISO to clearly see the difference. X-trans is clearly better for noise, and also clearly worse in detail.

It's just a function of the way the demosaicing works. You can apply noise reduction to Bayer to achieve a similar noise-detail tradeoff to X-Trans, but you cannot effectively turn it off on X-Trans and get the detail back.

That's a good point and surely correct when considering pure SNR. Visually it might look different but that's a matter of preference.

However, since we are now at 40mpx I suspect the level of details will be limited by other things than the color filter anyway. If someone makes a similar camera with bayer (they haven't yet), it might not be able to resolve any more details.

If so, wouldn't that eliminate the downside of less details, while keeping the benefit of sampling from a larger area?