Serious 20D problems

[dragon300zx]

The photographer I am looking at opening up a studio with is shooting with a 20D right now and he is having some serious problems with it so I thought I would ask you. We thought it was his 24-70L lens that was messed up but its his camera body. We have tried it with 3 different lenses and all have the same problem.

When you compose and focus the lense, and continue holding the button so as to lock focus, then recompose the scene, (keep in mind you have focus locked the entire time) when you finish depressing the button to take the picture it refocuses the lense in the instant you are pressing the button to release the shutter. As you can imagine this is a huge problem. Any idea's? This has to go back to canon doens't it. Anyone had this problem?

[pathfinder]

The photographer I am looking at opening up a studio with is shooting with a 20D right now and he is having some serious problems with it so I thought I would ask you. We thought it was his 24-70L lens that was messed up but its his camera body. We have tried it with 3 different lenses and all have the same problem.

When you compose and focus the lense, and continue holding the button so as to lock focus, then recompose the scene, (keep in mind you have focus locked the entire time) when you finish depressing the button to take the picture it refocuses the lense in the instant you are pressing the button to release the shutter. As you can imagine this is a huge problem. Any idea's? This has to go back to canon doens't it. Anyone had this problem?


Gary, I am not sure if I understand, but it seems that what you are saying is that the body refocuses after achieving focus lock with the shutter half-pressed.

One thought occurs to me - Has your friend set any custom -settings in the cameras set up software? This almost sounds like a custom setting. I would consider resetting the cameras custom functions to factory default before I shipped it off to Canon. The camera is set to One Shot, not AI focusing, right? I certainly am not sure that the camera is not defective, but I would reset to defaults first, before assuming that.

[dragon300zx]

Exactly it refocus's after focus lock is acheived with the shutter half pressed.

We reset the camera to facorty settings, made sure it was on one shot and not servo, all the settings are correct. Still does this.

[Andy]

Exactly it refocus's after focus lock is acheived with the shutter half pressed.

We reset the camera to facorty settings, made sure it was on one shot and not servo, all the settings are correct. Still does this.

is he is ai servo focus? you need to be in oneshot focus mode to do focus, recompose....

[dragon300zx]

We reset the camera to facorty settings, made sure it was on one shot and not servo (ai), ......
Yup its in one shot.

[Sheila Smart]

That's very odd. I suggest that your photographer try this: Set custom function to C.Fn-04 choosing #1. To quote Canon's manual "Convenient if you want to focus and meter separately. Press the <*> button to autofocus and press the shutter button halfway to attain AE lock". I now use this function and once I got used to it, I would not go back to having the shutter button do the focusing. One thing that you have to get used to, is to press slightly the shutter button to turn on the camera (if it went to sleep).

It might not work in your photographer's case, but its worth a shot.
Cheers
Sheila

[dragon300zx]

Thanks shiela I'll have him try this.

[pathfinder]

Exactly it refocus's after focus lock is acheived with the shutter half pressed.

We reset the camera to facorty settings, made sure it was on one shot and not servo, all the settings are correct. Still does this.

Does not sound good to me either then, Gary
:dunno

You have taken the battery out and done a cold reboot too, right?

[dragon300zx]

I'm gonna have him try setting the custom funtions, if that doesnt work another factory reset, if that doesn't work last ditch effort by reloading the firmware. If that doesn't work the body is going in.

[dragon300zx]

Shiela your fix seems to be patching it so he can use it for now but even after all that still wont work in the normal way. At least he can use it till things die down in a couple weeks and send it in.

[ginger_55]

The photographer I am looking at opening up a studio with is shooting with a 20D right now and he is having some serious problems with it so I thought I would ask you. We thought it was his 24-70L lens that was messed up but its his camera body. We have tried it with 3 different lenses and all have the same problem.

When you compose and focus the lense, and continue holding the button so as to lock focus, then recompose the scene, (keep in mind you have focus locked the entire time) when you finish depressing the button to take the picture it refocuses the lense in the instant you are pressing the button to release the shutter. As you can imagine this is a huge problem. Any idea's? This has to go back to canon doens't it. Anyone had this problem?

I might be having that problem, or I might not know how to operate the camera correctly.

And let me ask a kinda stupid question, which button are you talking about?

In other words, exactly how do you lock the focus. I am not doing it very successfully.

ginger (I know, I have read the manual, that is why I have not said anything before. I figured I was doing something wrong. That is why I said I "might" have the problem, not that I do have the problem.)

[Sheila Smart]

Thats good. But I can tell you now, that after a couple of weeks of using it with Cfn 4-1, he won't go back to the "normal" way:D

Cheers
Sheila

[Matthew Saville]

Thats good. But I can tell you now, that after a couple of weeks of using it with Cfn 4-1, he won't go back to the "normal" way:D

Cheers
Sheila
I now use this function and once I got used to it, I would not go back to having the shutter button do the focusing.
I second this custom setting! I use it every now and then with my D70, and it is VERY handy in many situations. Just takes some getting used to. LOL "some", it takes a LOT of getting used to...

-Matt-

[dragon300zx]

I might be having that problem, or I might not know how to operate the camera correctly.

And let me ask a kinda stupid question, which button are you talking about?

In other words, exactly how do you lock the focus. I am not doing it very successfully.

ginger (I know, I have read the manual, that is why I have not said anything before. I figured I was doing something wrong. That is why I said I "might" have the problem, not that I do have the problem.)When you depress the shutter button half way your lense focus'. If you don't release the button but keep it depressed halfway it stays locked on the focal point. WIth his camera after we get a focus lock at the half way point when the scene is recomposed (never lift your finger off the button or you loose your lock) and you finish depressing the button to release the shutter and take the picture the lense refocuses on its own when its not supposed to. Sometimes this will result in the lense picking another focal point when it moves sometimes you simply feel the lense move to refocus but it doesn't get a lock on anything. This is not supposed to happen (unless you are in AI Servo and want your focus to follow a specific object). It is supposed to take the picture without refocusing.

PS Pulling out a camera in a crowded starbucks, putting an assortment of lenses on the table, the two guys talking camera (might as well be greek), and taking tons of pictures when no one can figure out what they are taking pictures of draws alot of attention. So be prepared for looks from the staff. They never said anything but I thinks thats cause I looked like I hadn't slept for days.

[DoctorIt]

I thought this was a rather common 20D problem. Winger and one other sports shooter she knows both had 20D focusing issues - they went back to Canon for a fix. Of course, this takes several weeks - makes me think rather poorly of canon to know there is a bug in a whole run of 20D's and they won't just replace it or make the refurb quicker.

[mercphoto]

When you depress the shutter button half way your lense focus'. If you don't release the button but keep it depressed halfway it stays locked on the focal point. WIth his camera after we get a focus lock at the half way point when the scene is recomposed (never lift your finger off the button or you loose your lock) and you finish depressing the button to release the shutter and take the picture the lense refocuses on its own when its not supposed to. Sometimes this will result in the lense picking another focal point when it moves sometimes you simply feel the lense move to refocus but it doesn't get a lock on anything. This is not supposed to happen (unless you are in AI Servo and want your focus to follow a specific object). It is supposed to take the picture without refocusing.

Actually, AI Servo or AI Focus will refocus. ONLY ONE SHOT WILL NOT REFOCUS. But, as a general rule, using auto-focus in a lock-and-recompose manner is always a risky proposition and is not recommend.

[dragon300zx]

Merc recommended no. Used all the time, YES. None the less the camera needs to work the way it is supposed to but it's not :(.

[Sheila Smart]

Not wishing to labour the point, but I do highly recommend folk trying the Custom Function 4-1. It does allow one to focus using the <*> button and also by holding down slightly the shutter button, allows the 20D to take the correct exposure and recomposing. I had always been uncomfortable using the shutter button to focus AND expose. As I mentioned before, it takes a little while to get used to using the <*> but after doing so, it becomes second nature.


Try it, you'll like it:D

Cheers
Sheila

[Steve Cavigliano]

Gary,

If your friend is having this problem with all subjects using FLR (Focus Lock Recompose), in One Shot, he may have a faulty camera. Others have reported this same problem.

Here's (http://forums.dpreview.com/forums/read.asp?forum=1019&message=13196879) a really good thread that addresses this issue


Steve

[badrotation]

It is a bad shutter button.

What happens is when you go to press the shutter button all the way down to take the shot, it is momentarily causing it to lose contact, thus causing the camera to refocus before shooting.


It will be noticeably worse if you are putting pressure on the shutter button from an angle (not pushing straight down.)

It is a known problem on the cameras, and if you send it to canon, it is $176.

Personally, I just ripped the 20d apart and fixed it myself.

[Mike Lane]

It is a bad shutter button.

What happens is when you go to press the shutter button all the way down to take the shot, it is momentarily causing it to lose contact, thus causing the camera to refocus before shooting.


It will be noticeably worse if you are putting pressure on the shutter button from an angle (not pushing straight down.)

It is a known problem on the cameras, and if you send it to canon, it is $176.

Personally, I just ripped the 20d apart and fixed it myself.

Now that is great info!

[badrotation]

Now that is great info!

I have had three that have went bad , two of which went bad after only about 20,000 presses.

I just rip the camera apart, take the snap on cover off the switch, pull the contacts out (little spring metal disc 'buttons') clean everything up, add a bit more springyness to the buttons (to freshen them up to better than new condition), and then re-assemble the camera. I have never had a problem since, and the shutter button feels much more responsive (more noticable 'click')

Out of all three cameras, I only have two screws left over :rofl


It really is not a hard job at all if you have experience working with small stuff.