p.2 #1 · ['NEW Fix' UPDATE!] - MkIII AF still broken
Jeff wrote:
Thinking more about this, I'm now wondering if if the AF 'problem' is worse when shooting vertically, compared to horizontally...
I just took a look at the 'static' AI Servo series, which was shot horizontally. Interestingly, the 'motion blur' (for lack of a better descriptive term) tends to be in the same axis, in the same direction, e.g. it shows as ghosting to the right of the 'Brooks' logo.
p.2 #2 · ['NEW Fix' UPDATE!] - MkIII AF still broken
And, the last thing I took a look at tonight was prompted by DavidP's thread, and relates to accuracy of comparison sequences. In the 'slow' series, I was able to find the runner in virtually identical positions, in nearly the exact same spot on the track. The bottom 'loupe' view shows two things: that the focal plane was in a nearly identical position, and the runner was no more than 1 to 2 inches fore/aft of the exact same position in both images (note the slight softness of even the specular highlights in the MkIII image).
More importantly, the upper loupe view shows a significant discrepancy in the sharpness of the runner's face, even giving some wiggle room for the runner being up to 2" off in distance to the camera. It's this kind of result that MkIII owners familiar with the MkIII's AF problems readily admit to being anything but 'normal' for any camera. There is simply no logical explanation for it, other than some technically complex hardware issue.
p.2 #3 · ['NEW Fix' UPDATE!] - MkIII AF still broken
Jeff wrote:
Note in the screen grab below that (which at 1/8000th, I'd think is unlikely on RG's part).
I have no idea what component in the system could be moving, whether it is a result of the new anti-dust mechanism, due to the sensor moving (which seems unlikely), or some sort of overall 'looseness' in the parts of the camera that is exacerbated by the MkIII's extremely fast shooting rate.
Here are some more ideas, but I cannot check their validity as I don't own a 1D III. I hope, though, there is some idea in them that might give some spark to people who have a lot of experience with the camera.
1) try reducing the frame rate and check whether the problem still persists,
2) maybe the camera expects the lenses to be (slightly) faster in focusing but when the camera is taking the next frame, the lens is still settling for the latest focus change? After all, with the higher frame rate, there is less time for focus changes. Maybe not all lenses are fast enough to change their focus and freeze all movement before the next image is taken (being still in slight oscillation, which, with the ultrasound motors, would be of high frequency).
3) or maybe it is simply a timing issue in the firmware (sending the focus change command too late or opening the shutter too early)?
4) short exposures might actually make the problem more visible. If the unstable period is of a fixed length, it will be a much larger proportion of the whole exposure time. Therefore it would appear more often in bright conditions (as you get a shorter exposure time).
p.2 #4 · ['NEW Fix' UPDATE!] - MkIII AF still broken
Can anyone confirm if the anti-dust filter is bonded to, or part of the the same assembly as the bayer filter?
My thinking is that if the bayer filter is indeed part of the anti-dust assembly and there is an electronic glitch with the anti-dust filter control electronics, (or the assembly is mechanically loose to where high frame rates cause it to oscillate), maybe that is causing the odd "motion blur" that appears in a particular direction in relation to camera orientation.
p.2 #5 · ['NEW Fix' UPDATE!] - MkIII AF still broken
Jeff's conclusions are very interesting. I have no idea why ghosting appears in the out of focus shots but I too am concerned why -1 is dialled in on a perfectly calibration matched body and lens. I mean I have heard of athletics photographers having their bodies intentionally front focussing to catch the face in focus for the lean over the finish line but having to have -1 microadjust dialled in for every action shot in AI-Servo seems frankly ridiculous!
p.2 #6 · ['NEW Fix' UPDATE!] - MkIII AF still broken
I also see these strangely unsharp pictures.
In some cases like the logo on the t-shirt maybe there can sometimes be other explanations though, the edges of the stitching/printing is perhaps not all that sharp, maybe there's lens CA at the high contrast edge between blue and white, maybe there's sensor blooming because of local overexposure (though CA and blooming usually have a color to it). Just some ideas, I'm not saying this explains anything or everything of course.
p.2 #7 · ['NEW Fix' UPDATE!] - MkIII AF still broken
This is the 4:
1D, 1D2, 1D2MKIIn, MK3 = looks like number four to me, despite it's badge ...
Melor wrote:
I fully anticipate the production run of 1D3's to be the shortest in the 1D series. We will find out soon enough. I wonder if the next body will be a 1D3N, 1D4, or possibly skipping an unlucky "4" go right to the 1D5?
Paul
p.2 #8 · ['NEW Fix' UPDATE!] - MkIII AF still broken
It would be real interesting to do these shots at a small aperture, with great depth of field. If the ghosting still occurs, and there is a great range of front/back in-focus area, then we know for sure that the problem is something other than a focus problem. Perhaps as others mentioned, something mechanical/vibrating/processing inside the body that has nothing to do with the focusing system.
p.2 #9 · ['NEW Fix' UPDATE!] - MkIII AF still broken
Before reading this thread I thought I was the only one seeing that effect.
Looks really strange, but I remember that I noticed it on the first sample shots from the Mark3 that I saw on the internet.
p.2 #10 · ['NEW Fix' UPDATE!] - MkIII AF still broken
hfillmore wrote:
It would be real interesting to do these shots at a small aperture, with great depth of field. If the ghosting still occurs, and there is a great range of front/back in-focus area, then we know for sure that the problem is something other than a focus problem. Perhaps as others mentioned, something mechanical/vibrating/processing inside the body that has nothing to do with the focusing system.
Harvey
I agree and disagree, if you set your aperture smaller your shutter speed will decrease/slower. if this is caused by vibration in the shutter, then it may not show with slower shutter speeds 1/2000th or there abouts.
I would like to see this same sequence shot at a lower ISO, say ISO 50 or so, get the shutter down to where the camera can handle, 1/8000th shutter thats the max the camera can do. lets see these at 1/4000th or so and see the results. This too may rule out shutter vibration/ghosting/blur.
Jeff, thanks for pointing out your findings in the images , I agree there is still a serious problem, and I'm leaning toward something internally shaking/vibrating when the shutter is activated.
p.2 #11 · ['NEW Fix' UPDATE!] - MkIII AF still broken
I agree but you may want to be careful what you post.
Quote from the bottom of the article
"These photos are for personal viewing and printing only. They may not be republished in any form without the permission of the copyright holder. This includes the posting of these photos onto another server."
p.2 #12 · ['NEW Fix' UPDATE!] - MkIII AF still broken
72chevelle454 wrote:
I agree and disagree, if you set your aperture smaller your shutter speed will decrease/slower. if this is caused by vibration in the shutter, then it may not show with slower shutter speeds 1/2000th or there abouts.
I would like to see this same sequence shot at a lower ISO, say ISO 50 or so, get the shutter down to where the camera can handle, 1/8000th shutter thats the max the camera can do. lets see these at 1/4000th or so and see the results. This too may rule out shutter vibration/ghosting/blur.
Jeff, thanks for pointing out your findings in the images, I agree there is still a serious problem, and I'm leaning toward something internally shaking/vibrating when the shutter is activated. ...Show more →
I consistently see this at lower shutter too, with the overcast days I usually shoot at 1/500 to 1/2000 and it is still there. Not that my test is as consistent as RG but just shooting numbers of frames I still see it.
p.2 #13 · ['NEW Fix' UPDATE!] - MkIII AF still broken
Jeff - I know you're on to something here!
I was in yellowstone a couple weeks this september. I have several series of coyote where I was shooting at 1/2000th, F7.1, on a tripod where nothing in the photo is sharp. After looking at the ghosting, I can say for sure my camera is exhibiting this problem. It was not "hot" out, but bright and sunny when I took the photos in question. Despite f7.1, not a single item in the frame is sharp. Looking at some of the grass blades at 100%, I see the same ghosting effect.
I do use IS, I wonder if higher speeds with IS are causing the problem? Very strange.
p.2 #14 · ['NEW Fix' UPDATE!] - MkIII AF still broken
samd12 wrote:
I agree but you may want to be careful what you post.
Quote from the bottom of the article
"These photos are for personal viewing and printing only. They may not be republished in any form without the permission of the copyright holder. This includes the posting of these photos onto another server."
The "fair use" copyright exemption specifically covers "critique". I think Jeff is using these photos to critique the camera. However, I wouldn't want to make RG unhappy considering all he has done for Canon MKIII owners.
p.2 #15 · ['NEW Fix' UPDATE!] - MkIII AF still broken
Jeff wrote:
I did exactly that this morning as soon as I took a look at his images. Something tells me Canon will be a little less 'proactive' in running this one down. I think the submirror certainly fixed some issues with the jumpy/errant AF points, but this is clearly something different. And odd.
Maybe, but frankly I was impressed with the consistency of Rob's images between the two series. Gives credence to his shooting skills and methods, to be sure.
I too am impressed, but ideally the shooting skills of the person should not be a factor in the testing.
p.2 #16 · ['NEW Fix' UPDATE!] - MkIII AF still broken
John Ferguson wrote:
The "fair use" copyright exemption specifically covers "critique". I think Jeff is using these photos to critique the camera. However, I wouldn't want to make RG unhappy considering all he has done for Canon MKIII owners.
I agree John, I appreciate greatly both of their work ( I own a MKIII). I thank them both immensely. Please do no misinterpret my post.
p.2 #17 · ['NEW Fix' UPDATE!] - MkIII AF still broken
Steve Perry wrote:
I do use IS, I wonder if higher speeds with IS are causing the problem? Very strange.
Steve
Steve, I think there are some tests on pbase kicking around on this subject and as far as I remember they conclude that images are softer with High Speed Shutter with IS, I turn IS off if shooting above 1/400th probably should turn off above 1/250th
p.2 #18 · ['NEW Fix' UPDATE!] - MkIII AF still broken
if the lens had any focus movement during the process of an exposure it would cause the blurring, maybe the lens cant put the brakes on and stop the movement fast enough for ten frames a second. I would like to see Rob compare the two cameras dialed down to equal speeds 8 frames a second.
p.2 #19 · ['NEW Fix' UPDATE!] - MkIII AF still broken
I think it is a combination of longitudinal spherochromatic aberration, and one very slightly skewed lens element. Possibly an issue with a reflex from the front filter (if present).
Notice in the sharp picture, how there is a dark ghost text just where the bright ghost text is in the OOF picture. That is tell-tale of longitudinal spherochromatic aberration.
I´m pretty sure that if the camera was on a tripod, set on manual, lens focused manually using love view, and the lens then rotated in the bayonet lock, the resulting picture would reveal the ghost image to follow the lens rotation.
David
Edited by David Svensson on Dec 11, 2007 at 06:59 PM GMT
Edited by David Svensson on Dec 11, 2007 at 07:03 PM GMT
, I agree there is still a serious problem, and I'm leaning toward something internally shaking/vibrating when the shutter is activated.