p.5 #1 · ['NEW Fix' UPDATE!] - MkIII AF still broken
Hmm... Interesting, it does look very similar. Do you have any images shot at the same time that does not exhibit this phenomenon? i.e., is it random? If not, I might expect this to be some sort of more typical optical quirk (similar to the 'longitudinal spherochromatic aberration' that someone referred to earlier in this thread). Does it move around the image, or is it never shown in the center?
p.5 #2 · ['NEW Fix' UPDATE!] - MkIII AF still broken
My further guess....
Could it be 'longitudinal spherochromatic aberration', caused by the AF kicking in too quickly at high shutter speed.
While the glit is still sliding over the sensor, AF is getting more and more away from the in focus pont. Just maybe AF alogritm assumes exposure is ready in 1/8000 second, wheras in reality the sthutter travels in about 1/250 sec accross the sensor (and 1/8000 behind that, the 2nd blade closes)
on 2nd tought... would the direction of tis blur than 90 degrees from what we see now.. not sure
Could this also happen with another cam if put to MF and turn focus ring while making an exposure? Due to lack of time during daylight, I cannot test myself.
any valonteers to test?
p.5 #5 · ['NEW Fix' UPDATE!] - MkIII AF still broken
Okay... I am a bit confused on how the AF fails...
Does the OOF shots typically only happen when shooting sequences in AI-Servo with a long lens? Or is it just using AI Servo in general? What if I am using AI-Servo with a wide lens?
p.5 #6 · ['NEW Fix' UPDATE!] - MkIII AF still broken
aaronlam wrote:
Does the OOF shots typically only happen when shooting sequences in AI-Servo with a long lens? Or is it just using AI Servo in general?
Mine fares no better with an 85mm f1.8 which works perfectly on my Mark IIn so the problem is certainly not limited to very long lenses.
p.5 #7 · ['NEW Fix' UPDATE!] - MkIII AF still broken
Jeff wrote:
Hmm... Interesting, it does look very similar. Do you have any images shot at the same time that does not exhibit this phenomenon? i.e., is it random? If not, I might expect this to be some sort of more typical optical quirk (similar to the 'longitudinal spherochromatic aberration' that someone referred to earlier in this thread). Does it move around the image, or is it never shown in the center?
Interesting, though...
Yes there were others that day that did not show this effect with this lens, plus there were more with it. I was doing a pre-purchase test of this lens to compare with my 17-40.... so the FL was was being varied and this could explain the with and withouts.
I did do some more test shots the day after these (and after noticing the effect) to double check and I could reproduce the results quite easily.
With AF and IS out of the picture and the fact that this happens with no other lens (so the body is OK), it really only leaves an optical issue or an iris problem?
At first it looks like motion blur or perhaps a shift in focus, but this was shot AF off, 1/1000 sec, tripod mounted, mirror lockup and shutter delayed. It's not even a corner crop, as it comes from the middle-top of frame.
p.5 #10 · ['NEW Fix' UPDATE!] - MkIII AF still broken
Jammy Straub wrote:
Hopefully Jeff will contact RG with his analysis of the photos Rob posted. I'd say there's no reason to believe RG's coverage of this is over. He knows there's still a problem, and if someone presents the problem in a well thought out manor, he has no reason to not bring it to the public eye.
So yeah.. um anyone got Rob's number for Jeff?
I've heard back from neither RG nor CW, though it's only been 24 hours since I e-mailed them. I can't say that I expect to hear back from Chuck, but I'd certainly expect Rob to respond.
p.5 #13 · ['NEW Fix' UPDATE!] - MkIII AF still broken
DavidP wrote:
Jeff, a guy over at DPR (Pix-something) has stated that he sees this weird "ghosting" even in the 1D2 shots on RobG's site.
Have you looked for them there, and if so, have you seen them?
I did look in one of the MkIIn's 'fast' series, and did not see them. DPR has a similar thread going on about the 'ghosting' issue? I'd be curious to see a link if you have one..
PS: Maybe it's the "pix-something" who posted the brick pictures above?
p.5 #14 · ['NEW Fix' UPDATE!] - MkIII AF still broken
pixelpix wrote:
What does this mean in relation to RG's images? Probably nothing, but it is interesting that a VERY similar effect can be seen in an image where AF tracking and IS was not even involved.
I'd guess your issue is indeed entirely un-related. My basis for that guess is that it's only seen in an isolated area of the frame with only one lens on a different camera body. Perhaps it's some flaw in the manufacturing of your specific lens, a bubble in the glass or some such thing.
I'd send the lens in for service with example prints of the problem. Cheers.
p.5 #15 · ['NEW Fix' UPDATE!] - MkIII AF still broken
Jeff wrote:
I've heard back from neither RG nor CW, though it's only been 24 hours since I e-mailed them. I can't say that I expect to hear back from Chuck, but I'd certainly expect Rob to respond.
-Jeff
Thank you for being so pro-active Jeff. It's appreciated.
p.5 #16 · ['NEW Fix' UPDATE!] - MkIII AF still broken
My Mark 3 too often produces fuzzy ghost images.
Some people mentioned the Antidust thing as a possible cause for the problem. I noticed the same soft images effect on a 400D I used for a few weeks.
Edit: Now that I've compared several of RG's series I wonder, is the DOF smaller with the Mark 3? When the Mk3 focuses properly on the shirt the face is OOF - not so with the N, with which both face and shirt are in focus.
p.5 #17 · ['NEW Fix' UPDATE!] - MkIII AF still broken
Jeff wrote:
I did look in one of the MkIIn's 'fast' series, and did not see them. DPR has a similar thread going on about the 'ghosting' issue? I'd be curious to see a link if you have one..
PS: Maybe it's the "pix-something" who posted the brick pictures above?
p.5 #18 · ['NEW Fix' UPDATE!] - MkIII AF still broken
Jammy Straub wrote:
I'd guess your issue is indeed entirely un-related. My basis for that guess is that it's only seen in an isolated area of the frame with only one lens on a different camera body. Perhaps it's some flaw in the manufacturing of your specific lens, a bubble in the glass or some such thing.
I'd send the lens in for service with example prints of the problem. Cheers.
Luckily it was not my lens... it was on loan from CPS for evaluation purposes. I was considering upgrading the 17-40 and there were about 6 members on my site considering buying one also.... needless to say that Canon got no sales from us.
p.5 #20 · ['NEW Fix' UPDATE!] - MkIII AF still broken
Steve Perry wrote:
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.
I had exactly the same issue in Alaska in July shooting otters on overcast days at moderate/slow shutter speeds (1/500 -1/2000). Some shots of large floats at f4 or f/5.6, there is nothing in focus at all.
?
- I think you'll probably just see more MarkIIn's instead.
It's appreciated.