Stripes artifacts while recovering lights Sony A7IV

[Michele Caminati]

Recovering highlights from a Sony A7IV causes strange stripes artifacts on the overexposed areas, and just on those. (see image attached)

It happens with every raw type, compressed, uncompressed, and lossless compressed. Shot with mechanical shutter. The same problem shows on the Sony A7SIII while old Sony A7rII and A7S cameras don't show the problem.

I tried editing the image on the Sony imaging Desktop software (which is total crap of course) and the problem didn't occur. So I bet there should be a way of getting past the issue. Has anyone else found this strange behaviour with new sony cameras?

[TheDigitalDog]

Upload a DNG (which bakes your edits) using something like Dropbox or similar so others can examine the raw and the settings.

[Michele Caminati]

Here is a raw file straight from camera, never seen anything like that happen with any camera in my life!

https://www.dropbox.com/s/b9e7p4z4e3mn7tt/A7403899.ARW?dl=0

[TheDigitalDog]

I got the raw (NOT a DNG WITH YOUR EDITS) and indeed, you've got a scene where the dynamic range is way, way greater than the camera can capture so you have both clipped highlights and shadows. To the degree that no converter can recover the highlights (all three channels are blown out). RawDigger shows this with blue (black clipping) and red (highlight clipping) below. All you can do is target the exposure for highlights if that's important, you'll block up even more shadows. Or you need to look into multiple exposures and HDR but there isn't anything unusual here in terms of ACR; it can't produce data or details where none exists. Highlight recovery is very limited in the product, and only if one or two channels are clipped (one channel has some data). Again,  in your capture, all three channels are clipped:

[Michele Caminati]

I understand it's a photo where dynamic range is wider than what the camera can capture, it was indeed a test to see what the sensor could actually do. I was quite surprised when I saw the stripes, I have never seen such a behaviour. A clipped portion of an image should just be presented as pure white, without introducing artifacts that ruin also a part that is not entirely clipped. The Sony A7rII image can be recovered up to a certain point, and all is left is pure white, as it has always been and as it should be. I post a couple of edited jpgs and a link to the original A7rII file that is handled correctly by Adobe Camera Raw.

Sony A7IV:

Sony A7rII:

Original A7rII raw file:

https://www.dropbox.com/s/p5c8i2mteq62mjy/A7R03860.ARW?dl=0

Thanks for your time,

Michele Caminati.

[TheDigitalDog]

When I crank Recovery as far as it can go, I too see the stripes but again, the real issue is, there's nothing to recover. I suppose it might be useful for the Adobe team to view the raw and this ugly striping but striping or not, you're going to simply end up with totally clipped whites so moving Recovery is kind of pointless.

Adobe Highlight recovery has always been a work in progress. You might view your raw and set it to say Process Version 2; now that's going to be really ugly.

[TheDigitalDog]

FWIW, here's an old Canon 5D, two stops overexposed, Highlight Recover set to max (I used LR but its the same as ACR): I see no such strips. Can you capture a similar image with differing shapes and see if the strips show up? This could all depend on the camera (that 5D is very old). It could be any number of other issues; just wondering if you see this oddity with all captures this blown out.

[Michele Caminati]

To be honest I tried recovering the sun and nothing strange did happen, just regular blown out details, no weird stripes. I think horizontal lines and details such as the radiator in the picture and a shelf of books in another sample I took help to exagerate the probelm. I would be nice to examine the cause of the problem and try to fix it, it would be a decent recover of details if the stripes didn't occur. The Sony A7rII file doesen't seem to have more information left compared to the A7IV file, just seems to be treated better by ACR.