See the in-depth review of the Ricoh GR.
More blog coverage of Ricoh GR using Search: link, just above.
No camera/brand is without some issues. The Ricoh GR is remarkably coherent in its design and performance, but it shipped with the circular ring artifacts issue, apparently caused by vignetting correction, even for raw images, causing irreversible damage to the original raw image. See examples further below.
Context: the frequency of the Ricoh GR circular ring artifacts issue is very low (seen only a few times in thousands of my images), and it pales in comparison to the far more damaging and commonplace shutter vibration in the Sony A7R.
Ricoh contact and response
I first contacted Ricoh about the circular ring artifacts behavior on 2013-09-06.
On 2013-09-12, I uploaded two DNG files showing the issue to the Ricoh FTP server. An express condition of supplying those files to Ricoh (which I made explicit in bright red type) was that a timely response to my inquiry was expected.
With some persistence and insistence, I have finally received on Feb 20, 2014 a response to my inquiry. That is a ~6 month delay. As both a customer and a member of the press, that kind of delay is unacceptable. Moreover it was/is a violation of my terms in supplying the files to Ricoh.
But the good news is that Ricoh has delivered a firmware update that seemingly addresses the issue (not yet confirmed with field use).
Firmware update 3.00 for the Ricoh GR adds a feature to disable apparently vignetting correction, or at least that’s the way I interpret “Ambient Brightness”. I have applied the update to my Ricoh GR, but I have not retested the camera as yet. And of course it doesn’t fix the circular ring artifacts (“Ring shadow effect”) in images already shot.
The response below suggests that the circular ring artifact issue was/is caused by vignetting correction. I have not confirmed that it works, but it seems likely.
Ricoh has evaluated the images you submitted and this is what they advise.
1) Update the GR firmware to version 3.0 available from.
2) Firmware version 3.0 (along with other enhancements) adds an [Ambient Brightness] to the [Setup] menu.
3) Go to the [Ambient Brightness] setting and select [Original] rather than [Normal] (Default setting) in this menu.
This should reduce the appearance of the "Ring shadow" effect when shooting in DNG RAW and attempting to recover deep shadow detail in difficult lighting situations such as your sample images.
DIGLLOYD: a behavior that irreversibly alters raw image file data is not a “setup” setting; it’s a shooting parameter that belongs in themenu.
A permanent alteration of raw data is not analogous to the choice of color space or other JPEG settings; those are all post-processing settings for raw images having no effect on the raw file.
Hence the Ambient Brightness setting which does alter raw data belongs under the
Corrections for raw with other brands
Other cameras and brands have lens corrections; the question is whether these apply to raw files, e.g., whether the raw file is permanently and irreversibly altered. The only really correct solutions are to either give the user the choice (I favor this one), or to never alter raw data (fine, but has a few drawbacks in some cases).
- Sony cameras do not alter raw files, but some raw converters apply corrections during conversion (silently, see also), while others do not. But at least the original files are unaltered.
- Fujifilm X cameras are the worst case: vignetting and distortion and probably color fringing are always corrected and the user has no choice in the matter.
- Leica M offers optional lens corrections via coded lenses. The correction is for color shading and vignetting only. Your author has not observed ring artifacts.
- Canon silently corrects brightness for its EF lenses at wide apertures. This is not vignetting correction but another kind of EV matching algorithm.
- Nikon does not alter raw files for its DSLRs.