EOS M50 - Sensor or CR3 Data issue? Vertical Banding & Color Loss

[AiDon]

Hi,

I have attached a couple of images that show a distinct problem with RAW images from the EOS M50, unfortunatly it is 3 years old so there will be very little will to look at these and I belive expensive to correct.

The first issue is the inability to recover shadow detail from an image shot at -2EV either in DPP or in other RAW processors and the vertical banding can be seen distinctly.. The general consensus amongst the commercial RAW image processors is that there is simply not enough data available in the RAW image to recover the detaill. Note that the attached screenshot showing the banding is from DPP.

This second image shows skintone missing in the areas noted. It is also missing from the RH side of the actual image and shows up as a grey blotch on the skin. Again it cannot be recovered because there is no color detail.

These are just examples of some problems with the images coming out of the EOS M50 and seems to be mainly associated with backlit images. Note I also have other camera brands that don't exhibit the same symptons in similar situations, and Canon mirrorless or DSLR writing CR2 images don't have the same issues.

Note it is easily repeatable. Is there any way that I can correct this issue as it doesn't seem limited to the M50 as I have also seen similar issues with the EOS R & RP reported here and on other forums.

Is there any way the engineers can explain this issue? I am also willing to send the images so they can examine.

Regards, Don

[AiDon]

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@ebiggs1 wrote:

"The general consensus amongst the commercial RAW image processors is that there is simply not enough data available in the RAW image to recover the detaill."

I agree with these folks. There is just so much you can do. Everything has its limits. DPP4 is a capable program but I prefer Photoshop.  I think you will have much better luck recovering any possible detail with PS. The skin tone thing, I think you  might be too critical and that is likely just how the camera saw the portrait.

The banding issue will be worse in extreme conditions. Don't go crazy with the editing sliders especially clarity.

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Yes, obviouslty the skin tone issue is a dead loss and Clarity is not an issue with the other image (actually I have lots with the vertical banding) as it is not used. Simply using Shadow recovery accentuates the banding. And adjusting blacks doesn't help.

These issues are not there in images from 5DsR, 5D Mk3, 7D or my wife's M100, but they all use CR2 and different sensors except for the M100. Note not there in my Sony work cameras either, but that is neither here or there.

[ebiggs1]

"These issues are not there in images from 5DsR, 5D Mk3, 7D or my wife's M100,..."

You are correct because these are all different sensors and have different characteristics. They are going to have differing IQ. The M50 was/is not a top of the mark camera like a 5 series.

[AiDon]

It seems that the issue is mainly concentrated in the Red channel with a little in the Blue channel.

RED Channel

BLUE Channel

[Peter]

So...you disagreed some days ago and now you can't even show any proof of dynamic row noise removal in PS. Instead you tell me to buy a book. Does this book about dynamic row noise removal in PS even exist? What is the name of the book? Which page is about dynamic row noise removal?

[ebiggs1]

It is not my job nor intention to defend PS or to teach you how to use it. My gut feeling is you don't like PS because it isn't free. I have read some of your earlier replies to folks.  I do use Darktable and a few other open source software so I am aware of their capabilities. If you want to learn how to use PS to its full ability you need to do as I have done.  Take a class or buy an instructional book.

PS. Now before you go off on the freeware programs and how they are so much better, I simply mentioned Darktable because it is the best of them but it is in no way as good as Lightroom.

[Peter]

I am looking forward to see your PS correction of dynamic row noise. You know how to get in touch. I will wait.

[ebiggs1]

" I will wait." 

My advice, don't hold your breath and buy the book or go to school. I am not going to teach you how to use PS and/or LR.