As various owners report problems with their Ricohs I will add them here so others may know if what they experience is an easy self fix or a warranty fix.
R3 Flash unpredictable and usually overexposing.
Would never give a reliable result, so returned for warranty fix. Came back "calibrated" and now works like the manual says. Keep to Auto ISO and the ranges stated in the manual. It is a tiny flash and easily obscured by the fingers, so don't expect miracles.
R3 Shutter Button Worn "Chrome"
The shutter button after one week of busy use looked like it had 10 years of busy use. Button replaced under warranty. New button also wore the "chrome" off after a short time, I give up! Also the R% shutter button was wearing out after only about 1,000 shots.
R3 lens sticking at extended position, or not retracting fully. Same for R3/4/5.
Mechanism most likely jammed by sand grain, workshop fix, but may be a charge and not warranty fix at workshop's discretion as it really is a fault caused by the user, like dropping a camera. If no sand is found inside and it is a genuine mechanism jam then it will be a warranty fix.
R3 lens sticking closed, won't extend when turned on. Same for R3/4/5.
Lens barrel most likely sticking because of gunk buildup on outer lens barrel. Make it a habit of keeping the lens barrels very clean and wipe off dust and grime before it accumulates into a sticky mess. By sticky mess, I mean only a few tiny spots of dust accumulation caused my lens jam. And yes, if jammed shut it may take a dozen tries at turning on and off to get that lens to extend so it can be cleaned.
R4 top right corner severe vignettingCurrent problem yet to be answered, most likely lens cover leaves sticking. Yes, was lens cover sticking and that was caused by a hair caught in between the lens and the cover. Removed hair and problem fixed.
R4 severe vignetting, very obvious round shaped interference
Warranty fix for internal lens assembly not sitting in correct place as lens extends. Internally it seems that two small extra lenses drop into place when the lens comes out of the body, if one does not sit properly then severe vignetting occurs. Also seen once only on my R3, never happened again.
R4 banding in images
Banding seems most likely to occur with lens at max tele and a contrasty scene and usually with lens flare due to sunlight hitting the front element, but I have even had one occasion of banding on an R3 with an average scene and no flare. Some complaints have been fixed by a complete replacement of the camera, others by a replacement of the lens assembly. No clear answers as to why it occurs, but it should not occur at all.
R5 bad zoom lever
The R5 zoom control is a bad design and everyone seems to complain about it, why didn't they leave it as the easy to use R3 and R4 had it. This change for change sake was a definite backward step. Meanwhile at least one person has had an R5 repaired and it came back with a better feel to the zoom control. There may be a bad batch of early zoom controls out there. Later, I now have an R5 and the zoom control is no problem to get used to. There's just too much hysteria when things change. But still, the R3/4 zoom control is a better design. It's also a giant pain when using two cameras like the R3 and the R5, as inevitably I reach for the wrong button. Why the hell did Ricoh change that zoom control? Now the R6 zoom control is wrapped around the shutter button where it should have been in the first place, just like a pair of my Olympus digicams had years ago.
R5 focus errors
Many people are reporting R5 focus errors. My first tests at home showed that all was OK, but when on my holiday it did play up badly, maybe giving about 30% failed focus at full tele or near to full tele and also all focal lengths at times. That percentage fits with another user's reports about the same problem. So far after warranty fix my R5 seems to be focusing better, but I suspect it spends more time than it used to in the alternative focus mode where the CCD is used instead of the fast focus detector. Later use showed that the focus is still randomly unreliable so my camera was returned to swap for an R4.
R6 fuzzy top right corner
Some examples of the R6
are reporting that the top right corner is too fuzzy. All examples seen
by me do exhibit some top right fuzziness, but most are no worse than
the bottom left fuzziness of my R3.