p.13 #2 · ['NEW Fix' UPDATE!] - MkIII AF still broken
Not motion blur, the boys in the image are all critically sharp. This is a bit behind the plane of focus, perhaps it has something to do with reflections on/from the sensor?
Not sure David, I wasn't really looking for it, I just stumbled on it and it reminded me of RG's images.
p.13 #3 · ['NEW Fix' UPDATE!] - MkIII AF still broken
Alan321 wrote:
The IS operates by moving a lens group off-axis far enough and fast enough to redirect the light that is coming from a now-off-axis viewpoint back to where it was on the sensor. That way we keep the old view on the sensor even though the lens is actually pointing at a slightly different view. This assumes that the lens motion is mostly angular rather than purely "sideways". i.e. the camera and lens face a new direction and the sensor initially sees a different scene from the new angle of view. The IS corrects that by restoring the original scene, within the mechanical limitations of the IS group to respond.
If the IS group has incorrectly moved to turn that scene when there has been no corresponding turning of the camera then in effect you have a sort of tilt-lens effect that can shift the plane of focus so that it is no longer parallel with as well as coincident with the sensor plane. It will now be at an angle to but probably cutting through the sensor plane. The IS group has not changed the focus distance, but just turned the focused image plane off-axis.
In the early days of IS it was a plastic bag full of fluid held between two flat pieces of glass - one fixed and the other twisting without actually moving off-axis - so that it was in effect a variable prism lens ("vari-prism"). Nowadays it is more like a double-concave lens that moves sideways off-axis without twisting. The middle bit of the lens has less optical turning effect than the outer bit because it is more like a flat piece of glass. The farther it moves the more significant the optical turning effect becomes due to the shape of the lens.
- Alan...Show more →
I would have thought that for the small changes in "angle of aim" that result from our natural trembling (i.e., what we're trying to correct) the IS system would work best by offsetting a lens group from the axis but minimizing any resulting tilt of the focal plane. I can see, however, that it could be difficult to perfect the optical design, and even a perfect axial shift could result in a tipping of the focal plane just because the curves of the various lens elements are no longer aligned. I have neither the expertise nor the software to do a ray trace experiment to verify this.
It also seems to me that since IS works so well when things are right, it must not induce significant tilt of the plane (barring some problem) or we wouldn't be able to get such sharp hand held images of brick walls!
p.13 #4 · ['NEW Fix' UPDATE!] - MkIII AF still broken
Photon wrote:
Could that one be motion blur? It looks as if the boy and the rope were moving down and to our left, and the brightest areas are what show the blur. Okay, I'm just fishing for an explanation that's not as mysterious as the MkIII problems. Motion blur sometimes shows up as ghosting in highlights, while darker details can seem sharp.
It isn't motion blur. Please notice in Jeff's example that the ghosting occurs only at the higher contrast transitions in the picture (but not necessarily at all high contrast transitions).
Other shooters have also noticed the ghosting issue with a 1DmkIII (e.g Wally Jarrett, the guy that owns and runs the forum for 1-Series cameras. Here is the URL for Wally's forum - http://www.1dseries.com/1d/index.php - please note, registration is required to participate in the forum.
I've also noticed a few posts at DPR regarding ghosting; however, it isn't a commonly reported problem.
p.13 #5 · ['NEW Fix' UPDATE!] - MkIII AF still broken
I don't think any of these 'additional' issues are going to be widely reported until there are a majority of 'fixed' cameras in the field. We can cross fingers that the submirror will fix some of it, but I don't see how it could.
p.13 #6 · ['NEW Fix' UPDATE!] - MkIII AF still broken
[Posted this separately, as well, but thought I'd get the info here. Will try to test camera focusing tomorrow, and get back to this thread...]
Contrary to current reports, MkIII's repaired for the submirror assembly do indeed get marked inside the battery case... yes, with a 'Blue Dot' (believe it or not; note the image below)). My paperwork also contained the canned language about "adjustments being performed, firmware updated", one of which is patently false (the firmware was already updated), the other of which is essentially a lie of omission, at best.
==> Can anyone with an unfixed, pre-Blue Dot camera confirm that this marking in my battery case is NOT also in theirs? I wish I could remember, but that spot on the right side sure looks like a 'blue dot' to me.
I called Canon to inquire what actually was done to my camera, and he confirmed that the 'stopper submirror' was replaced, even though my repair form did not contain any indication of a hardware replacement whatsoever. We argued about the ethics of that for awhile, but their take is pretty much that they are returning the camera to original Factory Specifications, thus we, as customers, have no 'need to know'.
I would strongly suggest that anyone who receives their camera back from VA with no indication that a hardware replacement was made call Canon Service (800-828-4040) to inquire what actually happened to their camera, and request such documentation.
I personally think, after all that we've been through, the absolute least we deserve is the truth as to what is happening to our cameras. Yes, I realize "they don't do that", but it doesn't make it right.
p.13 #8 · ['NEW Fix' UPDATE!] - MkIII AF still broken
You might be lucky Jeff, as it looks like you have TWO blue dots ...the repair may be twice as effective Either that, or Canon has you in their books as a "marked" man
Edited by deadeyedick on Dec 21, 2007 at 02:28 PM GMT
p.13 #10 · ['NEW Fix' UPDATE!] - MkIII AF still broken
Could the lens mount itself on the 1D III not be seated parallel to the sensor? I'm guessing it only need be out a small amount ~ few hundred um (not enough that we would ever notice it to look at it) to cause a problem.
This is one of those problems where there's a lot of different potential sources.
p.13 #11 · ['NEW Fix' UPDATE!] - MkIII AF still broken
My guess would be that Canon repair has a gauge that can be attached in such a way that it can measure mount-to-sensor distance and variation. I'm not sure, however, that the special setup in Virginia would have such a tool since they seem to be geared to deal with a specific set of problems.
p.13 #12 · ['NEW Fix' UPDATE!] - MkIII AF still broken
Jeff wrote:
==> Can anyone with an unfixed, pre-Blue Dot camera confirm that this marking in my battery case is NOT also in theirs? I wish I could remember, but that spot on the right side sure looks like a 'blue dot' to me.
Jeff, if you count the white dots and the one new blue one you got, that adds up to 13 dots, you know they leave that number off of elevators for a reason don't you
Just kidding, I checked my Trade-in blue dot camera (one that canon took off the shelves and fixed) new fixed one. and I have no blue dot in my battery area.
p.13 #13 · ['NEW Fix' UPDATE!] - MkIII AF still broken
@Jeff: Nice catch!
My pre-fix MIII didn't have any marking in the battery compartment.
My fixed MIII has a whitish dot, right where yours is.
Repair sheets over here in germany also state "stopper, sub mirror" replaced.
Costs for the part 0,58 eur, and labour for "sub mirror issue" is 128,00 eur.
Obviously you don't have to pay that.
p.13 #14 · ['NEW Fix' UPDATE!] - MkIII AF still broken
OK folks, as requested, post-repair test results, fairly informal, but similar to the initial testing I did, i.e. my son running at me. The only difference was the weather conditions, which one would presume would 'favor' the MkIII. Bear with me here for a few posts...
----------------------------------------------------------
AI Servo at 10 FPS, 70-200/2.8L IS at f/2.8, center point (no expansion), AI Tracking Sensitivity set to default (the middle). Pretty much stock settings. Took a 21 frame sequence, light capture sharpening just to better evaluate focal plane, viewed at 1:2 in the screen grab.
Here is what I considered to be 'in focus':
Edited by Jeff on Dec 28, 2007 at 12:09 PM GMT (Reason: fixed 2:1 reference)
p.13 #17 · ['NEW Fix' UPDATE!] - MkIII AF still broken
Here's a few more. This one was AI Servo because they were walking at me, same settings as before, though single shot (note that these two images are also center-point only, no expansion):
Edited by Jeff on Dec 22, 2007 at 07:49 AM GMT (Reason: added center-point comment)
p.13 #20 · ['NEW Fix' UPDATE!] - MkIII AF still broken
Needless to say, I am not amused. Either I suck, or this camera sucks. It's performing exactly as it was before I sent it in. It's going back right after Christmas, and someone's going to get an ear-full tomorrow...
Since mine only got the 'stopper, submirror', I'm guessing I needed at least one more new part for it to perform like some of the other repaired cameras. This doesn't give to too much confidence that they are able to determine which cameras need what.
Either that, or Canon has you in their books as a "marked" man 
