See the review of the Sony A7 / A7R.
The Ricoh GR had/has circular ring artifacts if the vignetting correction is not disabled.
But credible, indeed worse instances seem to be popping up with regards to the Sony A7R, namely in even relatively bright lighting.
Dominik W writes:
This is not the first report that I’ve received. I deem it highly credible.
I recently traveled to Antarctica with the Sony A7R and on top of the camera simply dying in what were reasonable working conditions, a lot of my images exhibit a circular purple banding problem to add insult to injury.
Sony should really learn how to listen to the needs of professional photographers and stop crippling an otherwise great sensor + lens combo with compressed raw output and fragile support electronics.
My Pentax 645D has taken abuse in jungles, a typhoon, harsh winters and in hot deserts and has kept on ticking. I have purchased the A7R as a backup for the Pentax assuming it was due to finally fail after all the hard service over the last few years, yet the Sony is the camera that has given up after very little use.
There is simply no excuse to dropping the ball on important details of an otherwise great camera. Shame on Sony.
PS: The image below shows one example of the banding. The top of the unprocessed raw, the bottom is treated to enhance the visibility of the issue. Even with minimal processing, the purple shows up in prints. I can send some raws upon request.
I had the vignetting correction off but perhaps it could have turned on at some point. At the moment the camera is dead so I can't check what the setting is. Maybe the raw has that info in the EXIF ? Would be interesting to know if the rings are always in the exact spot or if they shift depending on the colour in the image. I will go through more images and find some that are a vastly different palette, but from what I can skies show this issue more than things such as street scenes.
DIGLLOYD: I’ve examined the raw images in 16-bit ProPhotoRGB, converted in ACR and Iridient Digital and viewed also in RawDigger—the effect is visible in all, suggesting a baked-in problem. The first effect one notices is a magenta cast developing to the edges/corners. Accentuating color saturation in the blue channel makes a series of wide concentric rings clearly visible.
I’m inquiring about details, such as cameras settings and filter. Lens is the FE 35mm f/2.8 shot wide open at 1/3200 sec @ f/2.8, ISO 100. It is an excellent exposure with no loss of highlight or shadow detail, according to RawDigger.
If it’s not vignetting, it could be related to Sony’s 11 + 7 lossy compression scheme. Or maybe even distortion correct, as pixels are stretched. Between such issues and the unacceptable shutter vibration issue, Sony has some homework to do to be taken seriously.