7D focusing question??

[justsomedude]

I've spent time thinking about your striping issue (banding) and since it's in a particular area, I would hate to think it's a bad sensor... I know they issued (a while ago) a firmware update that dealed with some banding issues, however if you have a fully up to date firmware, then I dont want to do the disservice and make suggestions without really looking at the camera and knowing the situation first hand.

Fingers crossed and give us updates as you get your camera back.

Awin,

Here is my latest, and hopefully final, post on this issue. The 7D and 50mm arrived back from Canon yesterday, and both are performing well. A few notes...

1) The 7D was reported to be totally within specification. However, Canon did note in the service list that "electrical adjustments" were performed on the sensor. In my first round of tests, the bright vertical band is totally gone. So whatever the "electrical adjustments" were, it appears to have solved the problem. I don't know how it can be "within spec" yet warrant "electrical adjustments", but whatever, it's working - so I'm not going to bitch about their reporting details.

2) Since the 7D was JUST in for the AF issue a month ago, I decided to send along my worst Canon performer for this round of service - the 50mm. It turns out the AF board IN the lens was fried. Canon replaced it free of charge.

3) As of now, all of my Canon lenses focus very well with my 7D, and I am now a very happy 7D owner. The Tokina AF is still atrocious, and I have just packaged it for a trip out to THK in California.

This AF board issue leads me to wonder - am I frying my AF boards as a function of my own usage procedures? I realize that it is considered VERY bad practice to swap lenses with a camera body powered ON. However, the primary concerns with swapping a lens with a body in the ON position is attracting dust on a positively charged sensor (at least from what I could find). The second biggest concern I could find through my searching seems to be limited reports of frying IS systems on high end IS lenses. The least reported issue is frying an AF board (I actually found no reports of this issue due to hot-swapping lenses, so I guess I'm reporting it now).

I know I am not the most diligent at turning OFF my body when swapping lenses, but I am thinking I may have fried the AF boards of my Tokina and 50mm by swapping my lenses out improperly. What are your thoughts on this?

 

[Loswr]

The 7D and 50mm arrived back from Canon yesterday, and both are performing well. ...I am now a very happy 7D owner.

That's great news!

I know I am not the most diligent at turning OFF my body when swapping lenses, but I am thinking I may have fried the AF boards of my Tokina and 50mm by swapping my lenses out improperly. What are your thoughts on this?

I'm also not terribly diligent about avoiding hot-swapping, but it hasn't (yet) caused any apparent issues. At least they fixed it gratis - I'd be annoyed to be charged a few tens of dollars to repair a lens that only costs a few tens of dollars...

 

[awinphoto]

I'm glad they got it to work well with your canon lenses... Regarding the AF board... a year/year and a half ago or so I sent in my 7d and 17-40 in to be cleaned through CPS and asked for them to double check focus to make 100% I was getting the sharpest images with the lens, might as well... When they came back, the camera was notated that it was within specs however they said there was an issue with the computer chip with the 17-40 and they replaced it/fixed it for free. I dont recall bad focus before i sent it in, i just wanted to double check it, however it is fixed and i haven't had problems since. Regarding the computer chips goes, (AF chips), computer techs treat electricals with gloves and sterile environments, however we, as photographers, aren't nearly as protective of our lenses (especially the electrical contacts) nearly as much. That being said, I'm 100% confident the contacts are protected to an extent to account for this.

Your 50mm 1.8... is that a metal mount or a plastic mount? I've heard of the AF motor frying.... the 50 1.4 is infamous for that (for people who shoot constantly with that lens)... and that lens is almost 3x the price of the 1.8. So... given that, with this lens I wouldn't be as concerned as I would if it happened to my 17-40 or 70-200, etc...

Lastly, I wouldn't lose sleep over the turning off your camera when changing lenses, etc... I dont do that, but then that could account to my 17-40mm never mind.. haha. But then again I haven't had problems since so who knows. Use your best judgement. If you're in a dry climate with a lot of static electricity, then by all means... if you're in a moist climate, then maybe not so much... You know denver better than I do but keep us updated as you see fit. Keep in touch with your ventures.

 

[justsomedude]

Thanks for the replies Neuro and Awin. I have a few projects in the coming days, maybe I'll post up the results... in happier threads.

 

[DarStone]

Hmm, sounds like a problem my brother had with his 7D, ultimately he sent it in to Canon,they updated the firmware and said something about a motherboard issue, it corrected his focus problem and they covered it under warranty.

 

[ronderick]

Thanks for sharing the experience justsomedude.

My gears will probably go in for maintenance sometimes in June, and I think I should ask the techs to specfically exam my camera's AF (getting a few front-focusing issues recently - don't know if it's just my bad focusing skills or problems with lens/body).

 

[maharzan]

Cool. I would love to see the new results.

 

[K3nt]

Just thought I'd chip in with some worthless information.
Hot-swapping lenses is mostly electrically ok, not the safest way but shouldn't be the culprit. The connectors are protected. What I would worry about is how does the camera react to the change in focal length vs AF motor drive current.
Some of the AF motors require a slightly different power level, if the camera does not detect this properly when hot-swapping you may indeed burn out the AF motor or associated control electronics.
Sometimes I forget too, but then I just switch the camera off with the lens off and when attached I switch it back on.
This may or may not be the issue but I have seen this same thing with other 'hot-swappable' electronics when the current requirement changes between components.

 

[justsomedude]

Cool. I would love to see the new results.

As promised, I'm posting a follow-up shot from my 7D with a 50mm f/1.8 lens after returning from Canon service. Focus point was on the vertical part of the kettlebell handle, and auto-focus was used. The hand and handle are all damn sharp. This was shot at f/5 - in hindsight I should've stopped it down more to get the entire kettlebell in the DOF. Oh well. 100ISO, with a very tiny amount of USM applied in post.

click for full-res


Sorry for the watermarks, but since I'm selling it as a stock image, I have to limit useage.

 

[unfocused]

Nice shot. How'd you light it?

 

[justsomedude]

Nice shot. How'd you light it?

Thanks unfocused!

This shot was lit with two off-camera speedlights triggered by the cheapie Yongnuo RF602 radio triggers.

The main light was a Canon 580exII bounced off a white umbrella. It was located just above and behind the camera position, about 4' off the gym floor. The umbrella was angled at an approximate 45-degree down angle and aimed directly at the kettlebell/hand area.

The side light was a Vivitar 285HV gelled red using the old DIY credit card gel holder trick (which only works on the Vivitars). The speedlight was 90-degrees off the camera position, about five feet to the left of the kettlebell. It was mounted on the Yongnuo radio shoe, which was attached to a Gorilla pod. The flash head was no more than 18" off the floor, and aimed directly at the kettlebell - or just five-to-ten degrees to its left (into the image).

Sorry, but I don't remember the power settings on the speedlights. I need to start taking better notes of my setups. :/

Here's a graphical depiction:

 

[justsomedude]

After experiencing various AF problems with my Tokina 11-16mm, I finally sent it in to THK Photo Products (Tokina's US servicer) in California for service/repair. It looks like Tokina is quasi-acknowledging a compatibility issue with the 11-16mm lens and the 7D. Here is the first response I received from the THK service representative in my email correspondence with him on June 13, 2011:

[quote author=THK Photo Products]In regards to the Tokina 11-16mm lens you sent in for repair, my technician has informed me that it was necessary to send your lens back to the factory in Japan.

We can offer you a replacement lens or arrange for a refund from the place of purchase.[/quote]

After replying that I would love a replacement (as I truly love the lens), I asked the service rep if a replacement would definitely solve my problem - as I would like to avoid a repeat of the same AF issue. Here is his response:

[quote author=THK Photo Products]Japan has found that when using this lens on the 7D, it works best when used in the Center Focus Mode. In the 19 point AF mode, the camera will automatically focus in on what ever is nearest in the frame, and this can cause soft images., However, when using the Center Focus Mode, the camera will focus in of the center of the subject without any problem.

We will replace the lens for you immediately.[/quote]

However, it is not clear why my original lens would have to be sent back to Japan, unless there is some type of update required on earlier models of the 11-16mm to make it compatible with Center Focus Mode on the 7D.

Anyway, it looks like this should solve my OOF problems, and I'm looking forward to receiving the replacement lens (even if it means I can't use the other focus points). I do love the Tokina 11-16mm, and am glad THK was prompt and responsive to my service request.

Hopefully others will find this information useful.

 

[Loswr]

[quote author=THK Photo Products]In the 19 point AF mode, the camera will automatically focus in on what ever is nearest in the frame, and this can cause soft images.[/quote]

Gee, you mean Tokina has discovered the normal behavior of automatic AF point selection? Regarding Automatic AF point selection Mode, Canon states, "When working with non-moving subjects in the One-Shot AF mode, the EOS 7D starts with all 19 AF points active. The camera will then use the point or points which “see” the nearest subject with adequate detail." I'm not sure what Tokina thinks the problem is here...

 

[justsomedude]

Gee, you mean Tokina has discovered the normal behavior of automatic AF point selection? Regarding Automatic AF point selection Mode, Canon states, "When working with non-moving subjects in the One-Shot AF mode, the EOS 7D starts with all 19 AF points active. The camera will then use the point or points which “see” the nearest subject with adequate detail." I'm not sure what Tokina thinks the problem is here...

Neuro,

Maybe I should've been clearer in my original post, but the problem I experienced was in manual AF point selection mode. Manually selecting any of the outside AF points would result in no-focus, and the lens would automatically focus on whatever was nearest to it. So, even if I had selected a distant object with an outside focus point - if something was closer - the lens would focus on that.

That, to me, is a problem - but can be overcome as long as the user is aware of the limitation.

 

[unfocused]

Okay. I was confused too. Because I was also thinking: "isn't that what autofocus does anyway?"

Glad you clarified that. I'm a big fan of the Tokina 11-16. At the risk of unleashing a firestorm of Canon lens fetishists, I have to say I think it's a better lens than the Canon 10-22. I'm going to have to try the center-point focus now. I guess usually, with a lens that wide, I haven't found focus to be as critical, so haven't really noticed the problem. Now, I'm curious.

 

[Loswr]

...the problem I experienced was in manual AF point selection mode. Manually selecting any of the outside AF points would result in no-focus, and the lens would automatically focus on whatever was nearest to it. So, even if I had selected a distant object with an outside focus point - if something was closer - the lens would focus on that.

Thanks for the clarification, that makes sense and also clarifies Tokina's response. It sounds like an issue with Tokina's reverse-engineering of the Canon AF systems not playing nicely with the 7D's AF system. That's a risk with 3rd party lenses, especially for bodies released after the lens. IIRC, in some cases Sigma offered to re-chip lenses in some situations, to correct problems of that nature. Maybe Tokina can/is working something out...which would be good, because by all accounts the 11-16mm is a very nice lens.

 

[justsomedude]

Okay. I was confused too. Because I was also thinking: "isn't that what autofocus does anyway?"

Glad you clarified that. I'm a big fan of the Tokina 11-16. At the risk of unleashing a firestorm of Canon lens fetishists, I have to say I think it's a better lens than the Canon 10-22. I'm going to have to try the center-point focus now. I guess usually, with a lens that wide, I haven't found focus to be as critical, so haven't really noticed the problem. Now, I'm curious.

Unfocused... I totally agree, and feel the Tokina 11-16mm is far superior to the Canon 10-22mm. I've owned both, and after comparing the CA and clarity between the two, I found that the Canon was no match for the Tokina (at least on my 40D). I'm hoping the replacement lens brings similar performance to my 7D.

Regarding the focus issues I had, check some samples on my website. Look for "Tokina" in the title of the problem images.

 

[ams]

I have a hard time getting a sharp image with my new 7D. None of the Sigma lenses I'd used with my old Canons work (looks like I need a major eye exam, even on auto-focus!) and I was told by my local Canon dealer that only the new Canon lenses are compatible. I've rented some Canon lenses, and the images are good, but I wouldn't call them razor sharp. Looks like I'm going to need new lenses. Does anyone have recommendations? For a start I'm looking for a wide angle zoom (12-24 range) and a general zoom (24-200 range).

 

[Mt Spokane Photography]

I have a hard time getting a sharp image with my new 7D. None of the Sigma lenses I'd used with my old Canons work (looks like I need a major eye exam, even on auto-focus!) and I was told by my local Canon dealer that only the new Canon lenses are compatible. I've rented some Canon lenses, and the images are good, but I wouldn't call them razor sharp. Looks like I'm going to need new lenses. Does anyone have recommendations? For a start I'm looking for a wide angle zoom (12-24 range) and a general zoom (24-200 range).

Any Canon EF lens is compatible, they have been made for many years now. The really old FD, and FL lenses are not compatible, and will not even mount to your camera. Older sigma EOS compatible lenses may be incompatible electronically with Digital SLR's, so watch out with used Sigma lenses, try them if in doubt.

The high resolution of the camera body means that to get sharp images when you view them 1:1, the AF must be near perfect. The camera has a facility called Autofocus micro adjustment, and I do it on all my lenses. On the 7d, it makes a huge difference to just tweak the setting by 2 points.

There are lots of writeups on how to do this, here is my favorite for adjusting your body to your lens.

http://regex.info/blog/photo-tech/focus-chart

You have two options, one is to adjust the body for all lenses, the second is to adjust it for each lens.

I always adjust it for each lens. for zooms, I use the longest focal length. Always adjust at maximum aperture.

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The second thing is to realize that the tiny pixels in a 18 mp sensor are more susceptable to shaking motion of the camera, so if you do not have IS, or have it tripod mounted, keep the shutter speed to 1/triple the actual focal length as a mimimum. Conventional wisdom is to use 1/equavalent focal length.

So, for a 100mm lens and no IS, use 1/320. Conventional wisdom would say 1/160 sec, and that works well on the lower MP cameras. You can experiment to find what works for you.

If your subject is moving, much higher shutter speeds may be required to freeze action.