Sailor Ted said:
With all due respect and a fair amount of conjecture, cars do have fender benders. If this car has had such a mishap perhaps it was repainted on the bumper, or around the bumper? If so the repair could have hit the color spot on when viewing straight on but could show a different cast when viewed from a different angle. I had just such a problem on a car of mine involved in a bender some time back and I did not notice it until a couple of years later when this was pointed out by an auto body repair guy.
Again just conjecture but possible?
With mutual respect, certainly it's possible. Usually, though, these mismatches are pretty easy to see, especially in good light. You probably would have noticed yours if you had parked the car out in the sun and taken a close look at it, moving your eye around to check how the metallic particles reflect from different angles.
No, normally I don't look at my car that closely either (I'm not a very good painter, so I don't
want to look all that closely!) but professional body men and car-show judges notice this kind of stuff immediately. You'll be looking at a car that you think looks absolutely sensational, and then a judge or an old-timer will walk up to it and immediately wave a hand at a certain area and grunt, "Ungh! What happened there?" Once you get used to looking for it, it's not hard to see.
(Those people look at cars kind of the way all of us look at pictures. You know how it goes -- a non-photographer will show you a picture he's taken of his kid or whatever and say, "Wow, isn't that a great shot?" and you'll think, gee, the horizon is tilted and there's a tree growing out of her head and the color balance is 'way too cyan and it looks like he focused about two feet behind her. But of course if you're smart, you smile enthusiastically and say "Great! What a cute kid!")
Anyway, even if the photographers didn't notice it at the time -- which I agree is plausible -- I think the EOS 5D would have had as good a chance to pick up such a paint variation as the M8 would.
So to figure out why it would show up in the M8 picture but not the 5D picture, we have to look at what the M8 has that the 5D doesn't or vice-versa, that might cause this type of effect.
I think the two most likely candidates for producing this kind of artifact are:
1) aliasing -- the 5D has an antialiasing filter and the M8 doesn't, so the M8 would be at risk to produce this effect via the subject detail interacting with the sensor.
2) noise -- this one just occurred to me as I was writing this. The pattern of flecks in metallic paint does look a bit like the pattern of pixel noise, and it's possible to imagine a camera with aggressive noise reduction "thinking" that the paint speckles are noise pixels that need to be suppressed. There's a pretty broad consensus that the 5D has stronger noise reduction than the M8, so it might have smoothed out the paint pattern to a greater extent. (In this case, it would be the M8 that was producing the more "realistic" rendition and the 5D that was producing the more "processed" rendition.)
As to why the speckled effect is visible only in the highlight area and not in the other areas, I suspect that's because of a characteristic of metallic paints. In a good metallic paint job, the metal flecks lie more or less parallel to the car body (you have to wait a certain amount of time between coats to let them settle) and that causes the metallic appearance to vary depending on the angle at which the light strikes it -- that's what gives a metalllic such a "lively" appearance, the way it changes as you move around the car. (There are even some finishes now with dimensional particles that provide different colors of lustre when the light strikes the car from different angles!)
Anyway, I wouldn't categorize this particular effect as an M8 "defect" -- I'd call it more of a "quirk." I suspect every digital camera has some quirks in how it renders particular types of "extreme" subject matter, types that a different camera might render completely normally. We normally don't notice them because these types of anomalous subjects are rare, but somebody who does a lot of one specific type of photography might find that a particular otherwise-great camera has trouble with that subject matter, while another does not.
It's kind of like the situation that arises with slide films, in which (for example) a particular kind of flower looks great on Film A but looks "off" on Film B... which in turn does a better job on a different kind of flower than Film A does. We've gotten used to it over the years with films... with digital, everyone's still crawling up the learning curve!
