p.47 #1 · ['NEW Fix' UPDATE!] - MkIII AF still broken
Hrow wrote:
Joe, According to Canon, the distance from the rear flange of the lens mount to the sensor was wrong. The lens mount was shimmed to make it correct so I have to assume that the distance between the two was too short. Remember that this is on an 8 month old camera whose performance was getting worse and the problem got worse each time it went in to Canon. After the last trip in I couldn't even pretend anything was in focus. The problem I am having with the explanation is this progressive deterioration as there was no slop in the lens mount.
From discussions I had with the Canon guy, their test equipment measures the distance at all four corners and the center. My camera was off on all measure points. I asked specifically if one point could be off and he said yes. As we discussed the repair procedure in such a case he indicated that they would use shims to bring that one side into compliance. The question was asked specifically for Jeff and several others who has been experiencing odd focus plane issues where one side is fine and the other side is totally OOF. So to answer your question, yes, people are experiencing problems that are almost certainly caused by asymmetrical distances between the mount and the sensor.
Combine this with the off-axis problems being reported by 1DsMkIII owners and you now have a situation where all planes of the sensor/mount relationship have had problems. ...Show more →
Thanks for the feedback. Sigh, bottom line, things don't look/sound very good if Canon actually tilts one corner of the lens mount relative to the other corners; this has to be extremely time consuming and therefore expensive (and I doubt any technician is going to get too excited about performing the task correctly).
Regarding Jeff, if ( big "if") I remember correctly Jeff had two problems with his non-BD body. One side of a shot could be in focus while OOF on the other. Also, he (Jeff) experienced situations where he couldn't even find the plane of focus (if Jeff is reading and I'm wrong perhaps he can re-calibrate my memory). Jeff's experience was very confusing to me and I never could make sense of what the heck could be wrong with his camera (apparently Canon couldn't either and they eventually replaced it with a BD body).
p.47 #2 · ['NEW Fix' UPDATE!] - MkIII AF still broken
This is ridiculous. The 1Ds MK II's sensor is larger than the 1D MK III and has the same pixel size, so focus distance errors would be worse. Canon managed to achieve appropriate tolerances on the 1Ds MK II back in 2004. I still wonder if the added complexity of the anti-dust system if responsible for some of the problems. Nikon may have known the pitfalls and therefore omitted an anti-dust system from the D3.
p.47 #5 · ['NEW Fix' UPDATE!] - MkIII AF still broken
EB-1 wrote:
This is ridiculous. The 1Ds MK II's sensor is larger than the 1D MK III and has the same pixel size, so focus distance errors would be worse. Canon managed to achieve appropriate tolerances on the 1Ds MK II back in 2004. I still wonder if the added complexity of the anti-dust system if responsible for some of the problems. Nikon may have known the pitfalls and therefore omitted an anti-dust system from the D3.
Apart from the Nikon part, I was thinking that too.
p.47 #7 · ['NEW Fix' UPDATE!] - MkIII AF still broken
Pixel Perfect wrote:
Why doesn't it affect the D300 with the exact same AF as the D3 then? It's got a dust buster.
I think the AD-system is one of the probs, not the problem. I think it could be the source for the problems of the ghosting artefacts as stated somewhere else in this forum. I don't think it's the source for the inconsistent focus behavior, but I could be totally wrong.
Never liked the idea of the AD-system in the 1D MarkIII. It didn't work for the 400D, so I didn't expect it to work for the 1D MarkIII.
p.47 #9 · ['NEW Fix' UPDATE!] - MkIII AF still broken
Yakim Peled wrote:
Then why it has no effect on the 40D?
Happy shooting,
Yakim.
Because that's the nature of speculation. Those who have hated the dust-buster feature are eager to jump on the bandwagon. It is certainly not at fault for either ghosting or focus issues.
p.47 #10 · ['NEW Fix' UPDATE!] - MkIII AF still broken
jvarszegi wrote:
Because that's the nature of speculation. Those who have hated the dust-buster feature are eager to jump on the bandwagon. It is certainly not at fault for either ghosting or focus issues.
I think that "certainly" as used in this context, might be too strong a word. Perhaps "probably" would be more accurate, since we haven't seen a definitive answer to some of the problems that some are experiencing. Short of a proven cause, many possibilities exist, all of which can be suspect until shown otherwise.
p.47 #11 · ['NEW Fix' UPDATE!] - MkIII AF still broken
jvarszegi wrote:
Because that's the nature of speculation. Those who have hated the dust-buster feature are eager to jump on the bandwagon. It is certainly not at fault for either ghosting or focus issues.
I have found the anti-dust feature on the 1DMkIII to work exceedingly well. That said, I don't know how you can make so definitive a statement that it is not responsible for ghosting or focus issues. Do you know something that you might want to share with us?
p.47 #12 · ['NEW Fix' UPDATE!] - MkIII AF still broken
I will shoot tomorrow. I'll let everyone know my results. I will try to post some bursts of 8-10 frames and we'll all get to see if the problem I have been experiencing is corrected. If it isn't it will be front focusing by 3 to 5 feet. Of course if they fiddled around with the sensor, it might now be back focusing by 3 to 5 feet. I am hoping the focus is right where its supposed to be.................ON THE SUBJECT!!!!
p.47 #13 · ['NEW Fix' UPDATE!] - MkIII AF still broken
Tom_W wrote:
I think that "certainly" as used in this context, might be too strong a word. Perhaps "probably" would be more accurate, since we haven't seen a definitive answer to some of the problems that some are experiencing. Short of a proven cause, many possibilities exist, all of which can be suspect until shown otherwise.
And I think you are right to say that it is all not certain.
I never said it IS, I said I think...
But it is all speculation so far... Although some here are very certain in their statements...To me these are the narrow minded...
Hrow wrote:
I have found the anti-dust feature on the 1DMkIII to work exceedingly well. That said, I don't know how you can make so definitive a statement that it is not responsible for ghosting or focus issues. Do you know something that you might want to share with us?
I have found it didn't work at all...
And I don't think he can share some info we're not aware of right now. He would be king of the hill if he did.
p.47 #14 · ['NEW Fix' UPDATE!] - MkIII AF still broken
dIggO wrote:
And I think you are right to say that it is all not certain.
I never said it IS, I said I think...
But it is all speculation so far... Although some here are very certain in their statements...To me these are the narrow minded...
I have found it didn't work at all...
And I don't think he can share some info we're not aware of right now. He would be king of the hill if he did.
dIggO
Not to be argumentative, but mine worked exceedingly well - at eliminating dust but it has had all sorts of focus problems. If your dust removal didn't work, did you have excessive focus problems? Who knows, maybe there is a correlation. I don't recall anyone asking a poll question that would lead one to determine a possible relationship.
On the dust issue. In eight months, I have never had to clean the sensor and never had more than a spec or two at a time. I'm not even blowing it out and I don't think twice about changing lenses in the field.
p.47 #15 · ['NEW Fix' UPDATE!] - MkIII AF still broken
I have focus problems as wel in AIS as in One Shot, AND I have dust problems, but that's the least of my concerns. I change lenses often, so I can live with some dust. When needed I use my rocket blower and sensor brush to take care of it. Never needed wet cleaning...
p.47 #16 · ['NEW Fix' UPDATE!] - MkIII AF still broken
dIggO wrote:
I have focus problems as wel in AIS as in One Shot, AND I have dust problems, but that's the least of my concerns. I change lenses often, so I can live with some dust. When needed I use my rocket blower and sensor brush to take care of it. Never needed wet cleaning...
dIggO
Well, so much for that theory.
Unfortunately, I think that the problem is much more fundamental than the anti-dust. I know (assuming Canon is telling me the truth) that in my case that it has to do with the distance from the flange to the sensor.
p.47 #17 · ['NEW Fix' UPDATE!] - MkIII AF still broken
Hrow wrote:
I have found the anti-dust feature on the 1DMkIII to work exceedingly well. That said, I don't know how you can make so definitive a statement that it is not responsible for ghosting or focus issues. Do you know something that you might want to share with us?
Sure, I know the elementary basics of the setup of SLR cameras, which anyone can know with a quick Google search or two. For starters, the anti-dust vibration system doesn't vibrate the sensor, much less the focus sensors. Even if the vibration system were active when the shutter was open (which isn't happening), it would be physically impossible for the clear plate that is vibrated to cause ghosting. Photons aren't trapped within the glass...
p.47 #18 · ['NEW Fix' UPDATE!] - MkIII AF still broken
Below is a link that shows how the how and where the lens mount is attached. This is from a 1DsMkIII but from what I understand the 1DMkII is very similar if not identical. From the drawing I can see how they could shim it but I can't figure out why they would have to. Looks like it is pretty much designed to be a non-movable location and not designed to be a test and adjust item on each camera. Thoughts on the subject?
Please add "http" to the front of the string. It was removed to avoid a direct link.
p.47 #19 · ['NEW Fix' UPDATE!] - MkIII AF still broken
Hrow wrote:
Looks like it is pretty much designed to be a non-movable location and not designed to be a test and adjust item on each camera. Thoughts on the subject?
My thought is that your problem was an isolated incident. If this was an issue in all cameras, all shots would be out of focus under all shooting conditions and shooting modes (one shot or servo mode).
p.47 #20 · ['NEW Fix' UPDATE!] - MkIII AF still broken
OK, so I apologize for being out of the loop for the last 8 days (was in Puerto Vallarta), but looking above, it would appear that we are all still speculating about all of this? No word from Canon yet? (I'll get through the last 5 pages, but don't have time right now )
