Drifting focus on 5D?
Discussion
I use a 5D at work, with a 1.8 50mm (cheapy one) and the 24-70 F2.8 lens.
Anyway, I'm sure they have recently started to have iffy focus in both cases. I'll use point focus on say F4, and the point focus is somewhere around 1cm ahead or behind of where I set.
I've not done a proper manual focus/live view on a tripod vs point focus on some lined paper yet, but it's clear even chimping over the images after taking them that the focus point is off.
Is there any reason for this? Damaged lenses? Damaged camera?
I'm also trying the pair on a 7D and it's doing the same kinda thing. It's only a fraction out, but it seems to be shooting beyond more often than too close.
Any really good super hard resets of all on-camera settings?
Can anyone recommend a good process to follow to determine the issue to single out the specifics? There are settings hidden everywhere on these cameras but I've tried my best to make them 'right' but still not sure if there is something going wrong.
The per-lens and global compensations for focus are all disabled/zero'd right now, first place I checked!
Thanks
Dave
Anyway, I'm sure they have recently started to have iffy focus in both cases. I'll use point focus on say F4, and the point focus is somewhere around 1cm ahead or behind of where I set.
I've not done a proper manual focus/live view on a tripod vs point focus on some lined paper yet, but it's clear even chimping over the images after taking them that the focus point is off.
Is there any reason for this? Damaged lenses? Damaged camera?
I'm also trying the pair on a 7D and it's doing the same kinda thing. It's only a fraction out, but it seems to be shooting beyond more often than too close.
Any really good super hard resets of all on-camera settings?
Can anyone recommend a good process to follow to determine the issue to single out the specifics? There are settings hidden everywhere on these cameras but I've tried my best to make them 'right' but still not sure if there is something going wrong.
The per-lens and global compensations for focus are all disabled/zero'd right now, first place I checked!
Thanks
Dave
Are you re composing? That will stuff it every time.
But its possible that theres some adjustment needed, as you use the gear you'll get to know it and see any issue s.
Use the built in ma, tripod + timed shot take a live view shot as reference target 50*focal length or at the distance you normally shoot.
Its normal for there to be slight inaccuracies on focus, check out lens rentals articles 'this lens is soft...'
But its possible that theres some adjustment needed, as you use the gear you'll get to know it and see any issue s.
Use the built in ma, tripod + timed shot take a live view shot as reference target 50*focal length or at the distance you normally shoot.
Its normal for there to be slight inaccuracies on focus, check out lens rentals articles 'this lens is soft...'
http://focustestchart.com/chart.html
Read through that page, print out the chart and do some controlled tests.
As the previous poster said, have depressing the shutter then re-composing will cause this effect.
Read through that page, print out the chart and do some controlled tests.
As the previous poster said, have depressing the shutter then re-composing will cause this effect.
When people say depress shutter then re-compose, is that where I'd point focus on the subjects eyes, and then re-frame the shot with partial button press... I take it the lens is literally drifting out of focus a bit due to the small movements etc?
I did do some tests with a moire pattern which showed lots of what I think was chromatic aberration, with the black lines blurring to a purple as the focus went out, and the heavy moire pattern disappearing.
I seemed to find that +3 > +4 achieved the best results via lots of timed tripod mounted samples against a test subject.
I'll re-do the settings on both cameras for both lenses with a quality test subject and post my findings.
We've had the lenses and cameras about 18 months to 2 years, and seemed generally fine. The went to New York recently though and came back with this weird issue, so I wonder if lots of manual focussing while AF is set (seen some people doing it with the 1.8 50mm, but I gather it's fine on the 24-70), as they are used a lot for video purposes.
Maybe it's just the lenses getting old and my expectations moving higher as I get used to the performance of them...
Thanks for the advice so far... I'll report back after more testing
Dave
I did do some tests with a moire pattern which showed lots of what I think was chromatic aberration, with the black lines blurring to a purple as the focus went out, and the heavy moire pattern disappearing.
I seemed to find that +3 > +4 achieved the best results via lots of timed tripod mounted samples against a test subject.
I'll re-do the settings on both cameras for both lenses with a quality test subject and post my findings.
We've had the lenses and cameras about 18 months to 2 years, and seemed generally fine. The went to New York recently though and came back with this weird issue, so I wonder if lots of manual focussing while AF is set (seen some people doing it with the 1.8 50mm, but I gather it's fine on the 24-70), as they are used a lot for video purposes.
Maybe it's just the lenses getting old and my expectations moving higher as I get used to the performance of them...
Thanks for the advice so far... I'll report back after more testing
Dave
Mr Whippy said:
When people say depress shutter then re-compose, is that where I'd point focus on the subjects eyes, and then re-frame the shot with partial button press... I take it the lens is literally drifting out of focus a bit due to the small movements etc?
Basically yes.Focus on someones eyes (center point, portrait orientation), then reframe so the point is actually on their stomach will put you inches out which can make all the difference.
Mr Whippy said:
When people say depress shutter then re-compose, is that where I'd point focus on the subjects eyes, and then re-frame the shot with partial button press... I take it the lens is literally drifting out of focus a bit due to the small movements etc?
I did do some tests with a moire pattern which showed lots of what I think was chromatic aberration, with the black lines blurring to a purple as the focus went out, and the heavy moire pattern disappearing.
I seemed to find that +3 > +4 achieved the best results via lots of timed tripod mounted samples against a test subject.
I'll re-do the settings on both cameras for both lenses with a quality test subject and post my findings.
We've had the lenses and cameras about 18 months to 2 years, and seemed generally fine. The went to New York recently though and came back with this weird issue, so I wonder if lots of manual focussing while AF is set (seen some people doing it with the 1.8 50mm, but I gather it's fine on the 24-70), as they are used a lot for video purposes.
Maybe it's just the lenses getting old and my expectations moving higher as I get used to the performance of them...
Thanks for the advice so far... I'll report back after more testing
Dave
New York eh?I did do some tests with a moire pattern which showed lots of what I think was chromatic aberration, with the black lines blurring to a purple as the focus went out, and the heavy moire pattern disappearing.
I seemed to find that +3 > +4 achieved the best results via lots of timed tripod mounted samples against a test subject.
I'll re-do the settings on both cameras for both lenses with a quality test subject and post my findings.
We've had the lenses and cameras about 18 months to 2 years, and seemed generally fine. The went to New York recently though and came back with this weird issue, so I wonder if lots of manual focussing while AF is set (seen some people doing it with the 1.8 50mm, but I gather it's fine on the 24-70), as they are used a lot for video purposes.
Maybe it's just the lenses getting old and my expectations moving higher as I get used to the performance of them...
Thanks for the advice so far... I'll report back after more testing
Dave
Probably jet lagged .....
You might want to get people to consider having the kit serviced - sounds like it may get quite a hard life. Or in the case of the 50mm lens maybe just get another copy and see what that does?
On the other hand if you are working with a shallow DoF the focus and re-compose technique may be a challenge. Are you using the central point and then moving? If so could you work with one of the other focus points to see what happens?
On the 5D I'm taking some head/shoulders portraits on the 50mm, and running maybe F4, taking a point focus at their cheek, then re-framing to centre their head in the image, so not really re-composing by much.
I'm probably about 90cm away from the subject though, so DOF is probably fairly shallow even at F4.
There is just an element of unreliability to the focus. If I just focus/shoot on their nose tip, then it's not in focus some times. Hopefully if I get the right compensation level in the camera setups then this problem will go away. I just need to make sure it's consistently out and not randomly out per focus event.
Yeah, servicing could be worth considering. The last thing you want is people who are not 100% with the cameras spending a day taking images to find out they are all not right. My time to check is probably more than getting them properly serviced would cost.
Dave
I'm probably about 90cm away from the subject though, so DOF is probably fairly shallow even at F4.
There is just an element of unreliability to the focus. If I just focus/shoot on their nose tip, then it's not in focus some times. Hopefully if I get the right compensation level in the camera setups then this problem will go away. I just need to make sure it's consistently out and not randomly out per focus event.
Yeah, servicing could be worth considering. The last thing you want is people who are not 100% with the cameras spending a day taking images to find out they are all not right. My time to check is probably more than getting them properly serviced would cost.
Dave
Mr Whippy said:
On the 5D I'm taking some head/shoulders portraits on the 50mm, and running maybe F4, taking a point focus at their cheek, then re-framing to centre their head in the image, so not really re-composing by much.
A cheek may not have enough detail/texture for the AF to get a good lock. Why not choose the sensor closest to the eyes/s? More detail to lock onto and less recomposing.To be totally honest, I've been using too many different SLR's recently to remember how to use each of the focus types reliably.
I've been using the 7D, 5D Mk2, and 5D mk1, and my D70s... and they are all quite different really.
I'll read up and do a hard reset on the 5D and 7D so I'm starting from fresh settings, then read up on the focussing features... there seem to be some weird and wonderful ones on the 7D especially, once you get down into the menus... I guess that is what you need for action/sports!
Perhaps some of these settings have been tinkered with, by someone, at some stage, and are messing up normal use now... gah. Novices being given SLR's and then following bloody Vimeo 'tutorials' on *cool* settings
Dave
I've been using the 7D, 5D Mk2, and 5D mk1, and my D70s... and they are all quite different really.
I'll read up and do a hard reset on the 5D and 7D so I'm starting from fresh settings, then read up on the focussing features... there seem to be some weird and wonderful ones on the 7D especially, once you get down into the menus... I guess that is what you need for action/sports!
Perhaps some of these settings have been tinkered with, by someone, at some stage, and are messing up normal use now... gah. Novices being given SLR's and then following bloody Vimeo 'tutorials' on *cool* settings
Dave
THe DoFMaster calculation tool gives the follwoing results for a 5D2 with 50mm at f4:
Subject distance 0.9 m
Depth of field
Near limit 0.86 m
Far limit 0.94 m
Total 0.07 m
In front of subject 0.04 m (48%)
Behind subject 0.04 m (52%)
Hyperfocal distance 20.9 m
Circle of confusion 0.03 mm
Not much to play with given the variable contours of faces.
I think if you are looking at relatively close up portraits the more common choices seem to be f8 (typically a sweet spot for most lense frequently used for portraiture) and then you work with the face from there taking into account its shape and the angle of the 'pose' and allowing for any movement of you or the subject from the plane of focus. If the lens is marginally out as well it could all get a bit unpredictable but to be realistic about it you really need to check the lens separately and for the working distance you plan to use in this case.
f8 will double the acceptable DoF.
Subject distance 0.9 m
Depth of field
Near limit 0.83 m
Far limit 0.98 m
Total 0.15 m
In front of subject 0.07 m (46%)
Behind subject 0.08 m (54%)
Hyperfocal distance 10.5 m
Circle of confusion 0.03 mm
Subject distance 0.9 m
Depth of field
Near limit 0.86 m
Far limit 0.94 m
Total 0.07 m
In front of subject 0.04 m (48%)
Behind subject 0.04 m (52%)
Hyperfocal distance 20.9 m
Circle of confusion 0.03 mm
Not much to play with given the variable contours of faces.
I think if you are looking at relatively close up portraits the more common choices seem to be f8 (typically a sweet spot for most lense frequently used for portraiture) and then you work with the face from there taking into account its shape and the angle of the 'pose' and allowing for any movement of you or the subject from the plane of focus. If the lens is marginally out as well it could all get a bit unpredictable but to be realistic about it you really need to check the lens separately and for the working distance you plan to use in this case.
f8 will double the acceptable DoF.
Subject distance 0.9 m
Depth of field
Near limit 0.83 m
Far limit 0.98 m
Total 0.15 m
In front of subject 0.07 m (46%)
Behind subject 0.08 m (54%)
Hyperfocal distance 10.5 m
Circle of confusion 0.03 mm
Simpo Two said:
Mr Whippy said:
On the 5D I'm taking some head/shoulders portraits on the 50mm, and running maybe F4, taking a point focus at their cheek, then re-framing to centre their head in the image, so not really re-composing by much.
A cheek may not have enough detail/texture for the AF to get a good lock. Why not choose the sensor closest to the eyes/s? More detail to lock onto and less recomposing.Ah, nice breakdown there.
I have a feeling the 50mm would be better on the 7D for these shots to get myself a bit further from the subject anyway...
7cm DOF is pretty shallow, 15cm would cover the nose back to the ears nicely however... F8 it is for future use
Still not happy the lenses seem a bit out though. I've agreed we need them servicing so need to research that a little now, then they can be sent off and checked over etc
Many thanks
Dave
I have a feeling the 50mm would be better on the 7D for these shots to get myself a bit further from the subject anyway...
7cm DOF is pretty shallow, 15cm would cover the nose back to the ears nicely however... F8 it is for future use
Still not happy the lenses seem a bit out though. I've agreed we need them servicing so need to research that a little now, then they can be sent off and checked over etc
Many thanks
Dave
Mr Whippy said:
Ah, nice breakdown there.
I have a feeling the 50mm would be better on the 7D for these shots to get myself a bit further from the subject anyway...
7cm DOF is pretty shallow, 15cm would cover the nose back to the ears nicely however... F8 it is for future use
Still not happy the lenses seem a bit out though. I've agreed we need them servicing so need to research that a little now, then they can be sent off and checked over etc
Many thanks
Dave
At the price of a 50mm it may not be worth it but the body and the zoom could be jointly serviced and calibrated. Canon (and their official service centres) seem to offer a fixed fee deal. They will re-do at no charge (in my experience) if not entirely happy.I have a feeling the 50mm would be better on the 7D for these shots to get myself a bit further from the subject anyway...
7cm DOF is pretty shallow, 15cm would cover the nose back to the ears nicely however... F8 it is for future use
Still not happy the lenses seem a bit out though. I've agreed we need them servicing so need to research that a little now, then they can be sent off and checked over etc
Many thanks
Dave
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