The Black Dot problem with the 5D Mark II had been brought up in the main 5Dmk2 thread. Unfortunately, with over 178 pages... it was barely discussed and eventually drowned by numerous other trivial discussions (memory cards, shutter sounds, availability announcements, etc). I thought the problem warranted more attention than that.
The issue has been discussed in this thread at DP Review. Clusters of black dots mysteriously appear on the right side of blown highlights from small light sources, visible even in normal prints. What's disturbing is that the black dots are not a JPEG artifact, but instead it's recorded in actual RAW data. This problem has been seen in many samples at DP Review, at Photo.net, and even at Vincent Laforet's website.
Why would these black dots only appear on the right side? Why are they even there at all? Does this look like something that could be fixed with a firmware update?
I'm hoping that someone with a technical background could offer some theories on the possible causes of this phenomenon.
maybe i'm being simplistic but this should definitely be something that will be handled in the firmware. even if its something hacky along the lines of the camera averaging the colour of the pixel from nearby ones
i doubt this will warrant any replacement programmes when software (cheap to distribute) could solve it
As to probable cause - it smells of some number overflowing and going from a very large number (white) to a 0 (black) but again this is just an ubstantiated hunch
This looks somewhat similar to the issue that was present in 1D II when it was released. There was, as far as I know, a firmware update that took care of it.
So is this an issue for super blown highlights only?
I was out taking photos of plenty of neon-lighting fixtures last night where there was a lot of very sharp contrast between light and dark and, while I didn't blow any of the neon highlights, I didn't see any black dots anywhere either.
jcbenner wrote:
Looks like it might be a Raw processing issue.
It's not a RAW processing issue. As I wrote in the original message, the black dots appear in the RAW data itself. There's a link up there showing the black dots in the actual RAW file before any demosaic process is even done.
I remember Chuck Westfall saying that Canon altered the way signal readouts are done in the 5Dmk2 sensor (compared to the 1Dsmk3 sensor). Perhaps this black dot phenomenon is a unforeseen side effect of that. I really hope this is something that could be fixed in a simple firmware update, as some people have already implied. Otherwise if it's a hardware problem, then Canon will have another embarrassing 1Dmk3 fiasco in their hands. Two major blunders in two years may be enough to put the final nail in their coffin, as far as the Canon's quest for redemption is concerned.
It does sound like it could be an easy firmware fix as long as the idiots in canons management pull their heads out of the sands and don't do a mkIII over this. It's such a shame given how the chip in the 5D mkII is potentially the worlds best in any DSLR.
Any estimate on the actual number of people who have observed this with THEIR 5DII bodies?
I propose a "Chicken Little" forum where threads like this can go until the "issues" they refer to are confirmed, in some objective and convincing manner, to be real and widespread.
this one will be a little harder for canon to dispute if it is wide spread,, seemed the 1dIII af thing they tried to continue to dismiss as it was so hard to rule out user error,
