7D and front focusing problems

[pmack]

I've read lots of topics regarding 7D focusing issues, and a lot of the time it turns out to be user error. others not.

For the last 5 odd years, i've been using a 350D, followed by a 40D, and have had very little focus problems. I typically always use the center focus point.

Yet i got the 7D several months back, and have simply been unimpressed with it's autofocus.
particularly seeing as the focus system was one of its selling points.


First dissapointment, was when i took some group photos of visitors at work.
With a wide angle lens, i had it on 19 point AF (i used to like using all points with a wide angle).
The points it said it chose were not in focus, and ruined most of my shots.
I've since learnt to avoid the 19 point AF like the plague (have seen so many terrible examples of it not working on the net)


second time was shooting some small surf with tony abbot, using the 100-400L
not a great shot, but newsworthy (was front page image the next day from the camerman next to me), yet it comes up OOF. A lot more shots from this day were the same.

I had it on single center point. AI servo. first 3 in the burst were like this, final one found focus. so yes it is possible this is normal operation, but i have had many many shots like this, not just the first few from a burst.

exif data should be in all the crops



water in front is in focus



The next time was shooting a performance for a family member.
i used the 50mm f/1.4
was very unhappy with the results. many of the shots were OOF, mostly all front focussing.
I was shooting at f/2 the whole night.

This one was from about 10-12 consecutive (not continuous) shots, all front focussed. although this time it was set to "one shot" autofocus, my focus is activated by my shutter button so was not possible to be user error (finger was pumped not held down)



fairly clear where it is focused:



I shot some more surf today to further check the cameras (or my) performance.
Today i set it to center point expansion, just incase it was having trouble with the one point.

Results were not terrible, but it was certainly not consistant.
Def seemed to be front focussing here and there.

this is probably not the best example, as it is trying to focus with some shadow, but the previous shot in this sequence was in focus.










I've done some basic testing with the 100-400L and it seems to focus correctly for stationary subjects. but when i need it to perform with the 7D, i have been very unsatisfied. it's like a third of the time the shots are good, a third the focus is sorta ok, and the other third are bad.


i tested out my 50mm f/1.4 this avo, and discovered it CONSISTANTLY front focuses.

focused on the corner of the post, shot wide open to help show where it focussed:


all the shots focused about a foot in front of where it was supposed to be focussed:


I suppose i could try a "micro" adjustment for this lens, but yeah regardless i think that is pretty terrible.


I dunno, feeling pretty disheartened about the 7D. has done little but dissapoint me because of all this.

Should i get it checked out with canon?
unfortunately i got it grey imported so will be a pain if i go through the place i bought it from (plus they would likely just hold onto if for a few months and likely say that everything is fine - so not worth my time)

thanks

[SnowA]

I noticed some front-focusing with my 7D and EFS 17-55. As you say, it was a bit of a let down, as there had been none with the 30D.

Did a not particularly scientific newspaper test on a tripod and then tried the micro-adjust. It seemed to fix it.

I must get around to testing with my other lenses some time, but I haven't noticed any gross mis-focusing with those.

[pmack]

it's like this new micro adjustment feature means canon can now release cameras and lenses that are hopeless.
they should all work from freekin factory!

whatever happened to quality assurance?

[I @ M]

pmack, I really think that you should sit down and investigate a few ways of doing some more "scientific" focus testing with your body and lenses.
The shots that you have posted might be a little challenging for the cameras AF system to totally rely on them as an indication of focus problems.
You will need a stable tripod, a bit of space, pretty good lighting and some reasonably high contrast objects to focus on. Then you can spend some time examining all the focus options varying from letting the camera decide which focus point to use, through to very carefully manually focussing, live view will help you a lot with that.
After doing all that and if you are still convinced that the camera is misbehaving then I am sure Canon service will be only too happy to inspect it for problems. If it is still under ( Australian ) warranty they will make any necessary adjustments as part of normal warranty service and if it is no longer within the warranty period it shouldn't cost an arm or a leg to have it fixed.
All cameras are just like most other mechanical devices, they are built to a certain tolerance level and the micro adjust feature of modern cameras is a very useful tool to individually fine tune your lenses to the body and vice versa, it is not a feature that allows camera makers to build bodies to "sloppier" tolerances.
Canon are no different to any of the other manufacturers when it comes to QC, their standards are pretty high and I don't think that accusing them of being hopeless is either a fair or educated comment to make on a public forum.

[ricktas]

Agree with Andrew, without doing some good old scientific based focus tests, it is hard to know if this is operator error, camera body, or lens causing this. If it is camera body or lens it is correctable, either using the micro adjust features of the 7D or taking it all to Canon and getting it calibrated.

Saying Canon are hopeless, doesn't quite cut it, for me, either. All mass manufactured items are done so with a 'fault tolerance', which is a known variation point within the manufacturing process, where an item is deemed 'correct' as opposed to one that is rejected. I am sure Canon would have this in place, like any other large manufacturer. It may be, here is the perfect model, anything outside 5% variation from this is rejected. Its standard manufacturing policy, and usually relates to what can be 'fixed/adjusted' to bring the item up to close to perfect, via the user, or a service centre. Anything outside the policy is a reject.

So you are having a whinge to the wrong people, we cannot fix this, you and Canon can!

PS, good to see you posting some photos!

[etherial]

Have to agree with the above. Have a look in the forums, there are a couple of threads on microadjust, I posted one as I was having all sorts of issues with my brand new 70-200/2.8 and focusing on the 7D. I too thought the camera was rubbish in this department. After my lens was serviced, and I did a thorough microadjust on it (and my others) I am pretty happy with what I get now. Make no mistakes though, it is a different beast to my other cameras the 450 and 50D.

The 7D has a huge amount of settings surrounding focus; I assume you would have read the manual regarding the AI servo rates that you can adjust in the custom menu's, they might be of help for the surf shots to get your hit rate a little higher. The others sound like consistant front focusing that a microadjustment would likely fix. And if it doesn't fix it, at least you have some examples you can send to Canon to show them what the issues are. (I did this and it meant that we could cut through all the initial "Have you tried..." stuff and straight to the point of the problem.

[pmack]

Guys i see your points, but I personally see it as a cop out to say "user error". As i said, I have already tested the 100-400L on a tripod, using liveview, manual focus, autofocus etc etc, and it performed as it should. So it is when it is having to actually perform under real conditions that it faulters.
If a camera (and lens) is being operated as it should, but is failing to produce many in-focus shots, then that comes down to the camera being the fault - regardless of whether or not there is something wrong with it. Of course you could say that if it is having focussing issues that you should use manual focus, but for such an "advanced" focussing system, i hardly see what i've been shooting as overly difficult. Yes it is not perfect subject matter, but the real world isn't. Cameras are not designed to just work under lap conditions!
I have had these focussing issues just about every second time i've used this camera, to say i am doing it wrong or using it in difficult conditions is not good enough IMO.
As I said, i've not experienced problems with my previous bodies (with the same lenses), yet with the 7D i am consistantly getting inconsistant results.

This is a grey import (but still under warranty), but as it is so inconsistant (except for the 50 f/1.4 which seems consistantly OOF), i don't fancy my chances returning it the the grey importers third party warranty service. I'd be more inclinded to send it to canon and pay for a calibration and/or diagnosis.

"I & M", i wasn't accusing of them BEING hopeless, I said it "was LIKE" they are allowed to be hopeless


anyway take enough shots and you eventually get some sharp ones... *rolls head*




oh and to further the point i was making with micro adjust, i had previously not heard of people having all these problems with front or back focussing problems.
yet these cameras with micro adjustments, many people seem to be having the problems.
so it's just a general observation that i've made. what if it didn't have it? people would be furious!

[agb]

There are plenty of examples of sharp focus with the 7D out there on the internet. The POTN web site has a heap of examples, so the camera does work. There are probably some instances where the camera has been sent back to canon for adjustment, so I would not definitely say that yours is not one of those, but in my view the first example, Tony Abbott in the surf, would not have been in focus when you pressed the trigger, as the focus point is not on Abbott. Can I suggest that you change the way you have set up your camera and give it another try. What I would do is firstly change your focus to one of the back buttons, I have mine set on the * button because it is more convenient for me that way.
Then if you have not already done so register the spot focus point, and deregister the 19 point. Then for a photo such as the abbott one, use the joy stick to move the focus point to one other than the centre, so that when you are doing the shot it is easier to frame the photo, in the example it would say be the one to the right of centre,with your thumb on the button and in AI servo you would have continuous focus, then the trigger can get the exposure and take the shot.
Being a cautious person myself I would do some testing with it in single shot instead of AI servo on some stationary subjects for a while to see if I could get it to focus.At least in single shot you get the beep and the green spot to confirm focus.

[Kym]

If you need to get scientific and check for front/back focus use this: http://pentaxdslrs.blogspot.com/2008...or-pentax.html (The test applies to any brand)
Until you set up a controlled test there is not way of knowing what is wrong.

Any mechanical device has manufacturing tolerances. A lens + camera is mechanical !

[MarkChap]

Wow, Canon actually provide the tools to correct these small errors in AF and it is still not good enough ??

What more do you want from Canon ?

This is also a good example of what can happen when you buy Grey imports, had this been a Canon Australia unit, you shoot it straight into them and get them to have a look at it.

Can I be blunt, Micro adjust your focus to suit each lens and then get on with shooting rather than worrying about front focus

[MarkChap]

oh and to further the point i was making with micro adjust, i had previously not heard of people having all these problems with front or back focussing problems.
yet these cameras with micro adjustments, many people seem to be having the problems.
so it's just a general observation that i've made. what if it didn't have it? people would be furious!

A quick and nasty google search suggests there were plenty of examples of 40D's Front Focusing
http://www.flickr.com/groups/40d/dis...7602780321680/
http://www.fredmiranda.com/forum/topic/608998
http://forums.dpreview.com/forums/re...ssage=26632115

[Speedway]

Guys i see your points, but I personally see it as a cop out to say "user error". As i said, I have already tested the 100-400L on a tripod, using liveview, manual focus, autofocus etc etc, and it performed as it should. So it is when it is having to actually perform under real conditions that it faulters.

I think you have answered your own question here Pmack. If it performed as it should with all external problems removed then it must be an external (user) problem. I had problems with action shots until I went from the multipoint to single point focus, which I select for where I want the focus point to be. Even with multi point for static shots, I never use all points, this gives me the control over where the camera focuses. The 7D is not a point and shoot camera and as such it is set up with a large number of user settings to get the most out of it.
Keith.

[MarkChap]

Don't forget that in the custom functions you can select whether you want the priority on Focus, Tracking, or shooting speed, when in continuous shooting AiServo
Maybe have a look at that also

[Art Vandelay]

There's really 2 seperate issues here.

If your getting focus sometimes and not others, it's not a micro adjustment issue. it's an AF issue (either camera or user). A front focusing problem will be there across the board, (with the same lens) it wont pop up every now and then. From that handrail shot, You may have to do that with your 50mm f/1.4 if you test it as descibed earlier up the page.

The surf shots with the 100-400 look and the dance shots with the 50mm are an AF issue as, as you say, some are OK. they're not an MA problem.

Adding to what mark said on the custom function of selecting AF priority, you can also adjust the tracking speed. i.e. how long it holds a point before switching to another. That maybe worth experimenting with, as some of those shots the area of focus is in a different area to where you expected them to be. The point may still be tracking that front wave instead of tripping to the surfer as you moved the camera. I wouldn't totaly rely on the DPP software showing which point was used, I've seen some anomalies in this, it doesn't also show the difference if it's used the main point or an expansion point in those modes).

from the canon site,


C.Fn III -1 – AI Servo tracking sensitivity

This Custom Function has five levels, from slow to fast. The levels are:

0 = Standard sensitivity. AF will momentarily pause if the AF point sees another subject while tracking.
-2 = Slow. Tracking will pause for a longer period when AF is disrupted to allow you to find the original subject with the AF point.
-1 = Moderately slow. Pause length will be between -2 and 0.
+1 = Moderately fast. The AF system will respond faster to a change in subject position.
+2 = Fast. AF system will not pause. If the subject escapes the AF point, the camera will instantly re-focus on the area the AF point is currently covering.
The focus tracking sensitivity refers to how the camera responds and switches to another subject during focus tracking. This response sensitivity refers to how long the camera waits before switching to a new target subject when the current target subject escapes an AF point. It doesn’t adjust how quickly the autofocus tracks. The shorter the response time, the faster it will switch subjects to track a new subject. Therefore, if you want to quickly track changing subjects, set the sensitivity to a faster level.

However, if you want to track the same subject as much as possible without switching to another subject, set this sensitivity to a slower level to force the camera to continue tracking the same subject, even if a distracting subject enters the frame or if the subject is erratic and likely to escape from an AF point.

You should try each of the settings out to find the one that works best for you, but generally, you will find that setting -1 or -2 for fast moving, erratic subjects produces better results.


There's a full explanation of all the custom functions here

[Arg]

If you are satisfied you have done the focus checking and there is no need to micro adjust, take it to Canon for a look. Cough up bucks. Forget the grey importer: if the camera focuses on a static subject on a tripod using live view, the AF basically 'works' and they will not entertain swaps, repairs etc.

Remember, the little squares on the screen are not the actual boundaries of the focusing area, it is bigger. And since Canon says in the manual that the camera will focus on the foremost object that it can, front focusing is always likely. The fact that you are having a front focusing problem and not a back focusing problem is the biggest clue to me that the camera is fine.

I had all the same issues. All gone now. Basically I had to learn the camera better. I certainly learned not to bother with 19-point AF, it will tend to focus on the closest object in the frame.

BTW, 'pumping' the shutter in one shot mode as you did for the upside down girl photos is likely to result in non-focusing.

P.S. the internet is bulging with scathing owner reports on Nikons, Canons, Pentaxi with focus and exposure problems. The cameras are rarely the problem.

[Arg]

Adding to my post #15 above, I notice your sample photos use lenses with small depth of field (100-400mm, or 50mm at f1.4).
Read this for a reality check: http://tinyurl.com/ycqz92d.

[MarkChap]

From Art's link above to Canon Professional Services

C.Fn III -2 – AI Servo first/second image priority

For AI Servo shooting, you can adjust the priority for the first shot or the second and subsequent shots. It deals with two issues:

1. How quickly the camera will fire if you suddenly press the shutter button fully.
2. If the shutter button is held down for continuous shooting, whether AI Servo AF will always take time to ensure correct focus for each shot (which may result in slowing down the drive speed), or whether the camera will always fire at top fps speed (even if proper focus cannot be ensured for each shot in the sequence).

There are four settings:

* 0: AF priority/Tracking priority – this will give more time to achieve focus before releasing the shutter and then during continuous shooting, focus tracking will be given time to keep accurate focus.
* 1: AF Priority/Drive speed priority – like setting 0, the first shot will prioritise focusing. However, after that the camera will try to maintain the maximum shooting speed. This is useful if the subject is large and easy to focus on, or not moving over great distances.
* 2: Release/Drive speed priority – this will fire the shutter as quickly as possible for the first shot, not giving as much time to finding focus. For subsequent shots, the camera will continue to fire at the maximum frame rate in preference to giving time to focus driving. If you have to capture the moment at all costs, this is a good option to use.
* 3: Release/Tracking priority – this will work like option 2, in that priority is given to releasing the shutter, but for second and subsequent images, the camera will then pass priority to focus tracking, rather than trying to maintain the maximum frame rate.

[pmack]

There are plenty of examples of sharp focus with the 7D out there on the internet. The POTN web site has a heap of examples, so the camera does work.

I'd like to correct you, that just prooves that some (hopefully most) versions of the camera work. A moot point. I'm not saying my camera is indicitave of all 7D's, I would certainly hope not!

but in my view the first example, Tony Abbott in the surf, would not have been in focus when you pressed the trigger, as the focus point is not on Abbott. Can I suggest that you change the way you have set up your camera and give it another try. What I would do is firstly change your focus to one of the back buttons, I have mine set on the * button because it is more convenient for me that way.

well no, the square was on tony for the previous 2 photos in that sequence, and they too were OOF. He simply fell down and I did not track his movement, but regardless, it has focused for 3-4 photos where the focus point was never at (at least not at time of the shutter press). Changing to the back focus button does not improve autofocus (unless previously you would press the shutter too quickly or not maintain a half shutter press). I have actually now changed to the back button but that is for creative controll (to effectively change to one shot, or manual focus in an instant).

Wow, Canon actually provide the tools to correct these small errors in AF and it is still not good enough ??

What more do you want from Canon ?

This is also a good example of what can happen when you buy Grey imports, had this been a Canon Australia unit, you shoot it straight into them and get them to have a look at it.

Can I be blunt, Micro adjust your focus to suit each lens and then get on with shooting rather than worrying about front focus

So a shot taken ~8 feet away, consistantly focuses at 7ft... sorry I do not call that a small error, that is huge.

Yes, a lesson learnt in grey importing.

As has been said by ArtV, this is not just a micro adjust issue, my 100-400 works fine in still, lab conditions. I would like it to perform well in the real world, as it did on my previous body.

I think you have answered your own question here Pmack. If it performed as it should with all external problems removed then it must be an external (user) problem. I had problems with action shots until I went from the multipoint to single point focus, which I select for where I want the focus point to be. Even with multi point for static shots, I never use all points, this gives me the control over where the camera focuses. The 7D is not a point and shoot camera and as such it is set up with a large number of user settings to get the most out of it.
Keith.

Ummm, no. It performed as it should in static conditions. The static conditions do not test out the tracking ability of the focus system. AT ALL. And yes thank you kindly for pointing out it is not a point and shoot...... really

Don't forget that in the custom functions you can select whether you want the priority on Focus, Tracking, or shooting speed, when in continuous shooting AiServo
Maybe have a look at that also

I have this setting to the default, which prioritises focus and tracking at the expense of burst speed, so the optimal setting considering my concerns. I would hate to see the results if I changed this to a “drive” priority.

[pmack]

There's really 2 seperate issues here.

Bingo, yes it seems there are two issues, however often several issues/symptoms are the result of one underlining problem, and that was the point of this topic. I wanted to see if people thought it were possible I had a problem with my particular body. What do they say two problems a coincidence, three a pattern? Perhaps we are just sitting at coincidence...

Adding to what mark said on the custom function of selecting AF priority, you can also adjust the tracking speed. i.e. how long it holds a point before switching to another. That maybe worth experimenting with, as some of those shots the area of focus is in a different area to where you expected them to be. The point may still be tracking that front wave instead of tripping to the surfer as you moved the camera.

Yeah it is probably worth experimenting, however in turns of tracking, surfing shots are not overly difficult unless you are zoomed in very close. If you miss the surfer with your focus point, you will usually pick up the wave behind them and that will usually still result in a sharp image.

In many many of my “front focussed” surf shots, the center point (or which ever one I had selected), was never at the position of where it focuses (and yes I understand it uses a bigger area that the square).

I am however going to return to using single point only, rather than single point with expansion because clearly that was not the problem in the first place. Expansion is more likely to pick up the foreground also. I want to take away any excuse for my camera to do that. I would change from “point” to “spot” to limit this, but then the tracking would be terrible.

Remember, the little squares on the screen are not the actual boundaries of the focusing area, it is bigger. And since Canon says in the manual that the camera will focus on the foremost object that it can, front focusing is always likely. The fact that you are having a front focusing problem and not a back focusing problem is the biggest clue to me that the camera is fine.

I had all the same issues. All gone now. Basically I had to learn the camera better. I certainly learned not to bother with 19-point AF, it will tend to focus on the closest object in the frame.

BTW, 'pumping' the shutter in one shot mode as you did for the upside down girl photos is likely to result in non-focusing.

P.S. the internet is bulging with scathing owner reports on Nikons, Canons, Pentaxi with focus and exposure problems. The cameras are rarely the problem.

The area of my “OOF” shots that are in focus, are not anywhere near the chosen point in many cases. I know the points are bigger than the display shows, but that still does not explain it. And yep, pumping was not exactly what I was doing, I just meant to say that I was removing my finger to refocus every so often while in single shot mode, meaning those 10-12 shots were not from the just one focus reading. It was just easier to explain that using one loose word

Adding to my post #15 above, I notice your sample photos use lenses with small depth of field (100-400mm, or 50mm at f1.4).
Read this for a reality check: http://tinyurl.com/ycqz92d.

Interesting link, thanks. “Right out of the box, cameras can be annoyingly inaccurate. ”
hmmmm isn't that nice....

From Art's link above to Canon Professional Services

C.Fn III -2 – AI Servo first/second image priority

not sure why you posted that. Changing that setting from anything but the default will give worse focus performance.

[rwg717]

Strange coincidence, I also bought a 7D some time ago and at about the same time a 70-200 f2.8 IS, I was really dissapointed with the pairing. However, at the time I was using a general purpose 24-70 f2.8 lens and the pairing was just brilliant for all sorts of work, but the 70-200.....now way!! I think it was after reading Ethereals thread on the subject I decided to have a fiddle with the micro-adjust and bingo problem solved. I still don't regard the 7D all that highly, like a horse that has thrown you once, you never quite trust them again!!!
Richard