Yi-M1 Dynamic Range There are two specific issues I have been planning on addressing since I started looking into the Yi-M1 JPEG capabilities. One is "dynamic range" and the other is "noise handling v. detail". These are related, but I am trying to address them individually. Looking at "dynamic range" here, I am only looking at the "Natural" finish. If I look at the "Vivid" finish or the others,, the results might turn out to be different. "P3030025-1b-rsz1200-C2.jpg" The golf course at Eglinton Ave. W. and Jane St. My eyesight is pretty bad. Even with my glasses I cannot see a lot of detail. So if I have a camera in my hand, sometimes I take a picture of simply to look at it later. When I was photographing the trees north of the golf course at Eglinton Ave. W & Jane St., I was looking up and wondering if there was anything interesting to see in the shadows. So I took "P3030049" [see also message #34 above]. I chose an EV compensation to get enough exposure into the shadows, expecting that I might lose some highlight areas. "P3030049-Crop02-C1.jpg" [Crop from 540,2300] This crop was all that I was really interested in seeing. After seeing it, I was satisfied that, really, there was not much of interest after all -- just some branches with pine cones and needles. That was going to be the end of that picture. I might even have deleted it at that point, but I decided to keep it for a while. As I was thinking about writing a bit about the Yi-M1's current JPEG processing, I looked through the files I had on hand and felt that this file showed a handful of issues I thought I would like to show. In particular, I was interested in the chromatic abberation issues. First, the 12-40mm kit zoom may not be wonderfully sharp but at the telephoto end in particular there was very little chromatic abberation. But there was enough to show the way the Yi-M1 handled it. It also showed a bit of the noise and resharpening issues. So I decided to use it as one of my first examples. Having used it for this, I started thinking about the other issues that it demonstrated. "Gee, it sure is too bad I didn't have the highlights covered by the dynamic range." Now that raises a couple of interesting questions. Exactly how much dynamic range does the Yi-M1 have to work with? Did I have enough that I could have "contained" the whole of this scene? Whenever I had the time, over the last few days, I chased after the the answers to those questions, and this is what I can say for now: First: If I had paid better attention to this picture, could I have set an exposure that would have covered the whole of the dynamic range in this situation? After trying my best with Corel PaintShop Pro 2018, I can say that no, it was not possible. It was close though. First, we know that I clipped the highlights. It does not look too bad. As I wrote above, I think an uncompensated exposure probably would have been enough to cover the highlights. But what about the darkest parts? I tried compressing the gamma curve using PaintShop Pro's "Histogram Adjust" capability, and then made a further fine adjustment in "Smart Fix". What I found was that there were a couple of very small patches of un-correctable "black" in the deepest shadows. Raising the levels of those areas eventually just shows noise. So that answers it. Even with the small patches of overexposed highlights at the top end, there is also unusable "black" at the bottom end. The sensor's dynamic range is exceeded at both ends. Lowering the exposure to bring down the highlights would simply have increased the black areas in the shadows. "P3030049-5c-Crop01-C1.jpg" [Crop from 540,2300] This is the best I could do adjusting the gamma curve to flatten the dynamic range and recover everything possible in the shadow area. Compare this to "P3030049-Crop02-C1.jpg" and yes, I think that I did manage to recover a bit of shadow detail, but not really much. I "think" I recovered detail? Well, if you look at it, the only thing for certain is that the noise is showing up, and there is some "greenish" area that used to be "black" in the original JPEG. I can "guess" that I am seeing more of the needles, but I am simply applying an assumption that it should be more needles. An "unbiased" analysis would conclude that "nothing was proven." But in the end, yes, you will find that there are still some patches that are definitely nothing but "black + noise". Still, the camera did pretty well. According to "YI M1 Review" by Mike Tomkins ("Imaging-Resource.com" posted: 09/18/2017) "YI M1 Review" The Yi-M1 has "... the same image sensor as in the Panasonic GX8". I do not have a reference, but I believe I also read that this is the same sensor which is used in the current Panasonic GH5. It might also be in the G9. Looking further, DXOmark had this to say about the Panasonic GX8: DXOmark GX8: Overall Score 75 Portrait (Colour Depth) 23.5 bits Landscape (Dynamic Range) 12.6 EVs Sports (Low-Light ISO) 806 ISO [Compared against Panasonic Lumix DMC-GH4 (16MP), Olympus OM-D E-M1 (16.3MP), Olympus PEN E-P5 (16.1MP), Olympus OM-D EM10 (16.1MP) their review continued as follows:] "But the difference between the sensor performance of these Micro-Four-Thirds cameras is so negligible that we can essentially say they offer the same image quality in terms of Color, Dynamic Range and ISO, despite the fact the GX8 benefits from greater resolution." I think that the sensor performance of the Yi-M1 would prove to be in this same ballpark, which is still about the same as some cameras which cost much more.