Still loving the M6II, even more with new DXO

R2D2 wrote:

Larry Rexley wrote:

I took a crack at a comparison using one of my most difficult images: I shot this image of two CSX conductors I call 'Bert & Ernie' riding the front of a train, back when I was still using Canon DPP 4 in June 2021.

The image was terribly underexposed, about 2.5 stops, and was shot with a 'hazy' vintage Vivitar 100-200mm zoom on the Canon M6ii. As a result the image was totally washed out with low contrast.

To look normal, the image must be pushed over 2 stops, shadow exposure bumped up, contrast ratcheted up to near 100%, and color saturation and vibrance increased quite a bit. Doing all that brings out horrible grain with extreme chroma noise.

Here's the image processed for everything except de-noise in DxO PL6 using the classic color profile. All images are cropped to about 70% of original size, then downsampled to 4k monitor size (my standard display and posting size).

DxO PL6, no de-noise, classic color, unsharp mask Threshold 0, Radius 1.1, Intensity 100

As seen in the next image processed in Canon DPP 4, the image is basically unrecoverable with DPP. By the time you get the de-noise high enough to clean up the grain and chroma noise, shadow detail is lost in the mud. Back when I was using DPP4, I though this image was lost forever, and darktable's better denoise options couldn't fix it either.

Canon DPP 4, my best shot at a usable image

Here's my processed image using PL6 with the original Deep Prime (not XD) and classic color profile, this matches my PL5 result. I increased the unsharp mask sharpness settings to reach a good compromise between grain and detail, this was my typical workflow with Deep Prime:

DxO PL6, Deep Prime de-noise Intensity 69, classic color, unsharp mask threshold 0, radius 1.2, Intensity 178

The next image is PL6 with the new Deep Prime XD. After a bit of experimenting, I found that I do not need to increase the sharpness with Deep Prime XD the way I did with standard Deep Prime - I tried to get both images to show comparable levels of detail. Also I found you have to be less aggressive with the Deep Prime XD intensity setting to get a similar result to the original Deep Prime --- here I used Deep Prime XD Intensity 59 instead of Intensity 69 that was used with the original Deep Prime in the previous image.

DxO PL6, Deep Prime XD de-noise intensity 59, classic color, unsharp mask threshold 0, radius 1.1, Intensity 100

Finally, I processed the image the same way as the PL6 Deep Prime XD above, but chose the 'Wide Gamut' color option that is new to PL6 instead of Classic color:

DxO Pl6, Deep Prime XD de-noise intensity 59, wide gamut color, unsharp mask threshold 0, radius 1,1, Intensity 100

Thanks for the samples.

My opinion (YMMV) is that I prefer the Deep Prime XD image.... my feeling is it has the same level of detail as the Deep Prime image, is still natural-looking, but does not have the grain. If I increased the original Deep Prime intensity enough to eliminate the grain, the image looked unnatural. A little grain in a 'Deep Prime' image seems to give it a little texture and keeps it natural looking.

Deep Prime XD seems to be able to keep detail and eliminate the grain better, leaving an image that looks more like it was shot at a lower ISO, with less grain than the original Deep Prime could.

Yes, I figure all in all I'm getting an extra stop out of DPXD. That is darn substantial.

I just did some of my own tests, based on your comments and Alastair's assertion that he feels the M6ii is capable of usable ISO 25k shots.

https://www.dpreview.com/forums/post/66710955

My findings support what you both say: My feeling was that with DPP4 I could only go to about ISO 3200... I was getting pretty messy results at ISO 6400. With DxO PL4 and PL5's Deep Prime I felt that I could get consistently good results to about ISO 12,800 -- about two extra stops.

With PL6 I think you're right --- I'm getting usable full-resolution images at ISO 25,600 or so! Above that the shadows start losing too much detail --- although Deep Prime XD can still clean up the noise, amazingly, and if you're careful, you can still get images that don't look like they were shot at such extreme ISOs with an APS-C camera.

I've been having fun going back to some "challenging" previous images and reworking them with XD.

However, the settings to get to that optimal 'balance' point seem to be with less aggressive sharpness and Deep Prime intensity settings.

The actual settings are indeed completely different. It's fascinating finding the right balance. Some types of photos such as birds and bugs can be slammed hard. Others such as people need a gentler approach (as MAC pointed out).

With further tests I found the DeepPRIME XD settings at 'full pixel resolution' weren't as different as I thought. I was getting good results by switching from DeepPRIME to DeepPrime XD, bumping the DeepPRIME luminance down by 5 points, and changing to Wide Gamut color space. I did not change my sharpness or any other settings.

The fact that you can use a lower luminance setting might reflect that the DeepPRIME XD is capable of a wider range of denoise, so they readjusted the scale?

I also find that I prefer the new 'wide gamut' color space over the Classic color space: the colors seem a bit richer, with a more natural-looking tonal gradation. and overall the image appears to have more 'depth' and detail due to more color contrast.

I'm going to have to try the new "wide gamut" color space. I used to use a HUGE color space in the past (ProPhoto), and that had a positive effect esp with some colors.

I'm also finding that the pixel-dependent extreme processing that astrophotography of the Moon, planets, and deep sky objects demands definitely benefits from PL6's slightly better Deep Prime XD de-noise, and the PL6 Wide Gamut color space.

So at the end of the day, for my needs, I'm glad I did the PL6 upgrade.

Definitely glad I did the upgrade. I don't see grain anywhere in the natural world. Only what my own rods and cones produce, and that's enough for me.

R2