AI Auto Focus repair - Canon / or new camera?

[BaconBreadBaker]

I have a 40D that's been plagued with focusing problems. The AI Focus and AI Servo are hit or miss, with the more frequent being a miss.

Is this repairable? And at what cost?
Or should I just sell and get a new camera? Any ideas on 40D buy back price?

[huja]

Do you have the latest firmware? It's quite common for Canon and Nikon to be aware of such problems and issue firmware updates to address the issues.

Also, check your AF settings . . . maybe do a reset to factory settings and go from there.

Is it missing the mark with various lenses? Or just one lens?

[BaconBreadBaker]

I have had latest 1.1.1 firmware for long time.
The problem is with 3 of 3 lenses.
I've reset the settings several times.

I used to do only "one shot" focus, and it would be 50/50.
Then recently I've been experimenting with AI Focus and AI Servo, and getting same results or worse.

It's like the focus is actually a foot behind the focal point, as most of my shots at f/2.8 are just a slight out of focus.

[huja]

Maybe this might shed some light on your AF issues. This guy gets the AF problems w/third-party and older Canon lenses.

Sounds like you have a great excuse to upgrade bodies!

[vinyljunky]

Strange, I was just talking to my friend who's having the exact same problem with the 40D. She took it back to Tin Cheung (where she bought it from), and they were unable to do anything as the store warranty had expired.

My suggestion was to take it to the Canon service centre in TST, to atleast get an idea of the problem and the cost to fix it.

[BaconBreadBaker]

I'll stop by TST service center to get it looked at. I was interested in upgrading the body too, so if I go that route then I need to find a suitable replacement.

Tin Cheung said they would give me $1000 for my 40D (lol), but I'm not sure what body to buy. I'm losing faith in canon and would like to switch to Nikon, (or Leica if the m9 wasn't so damn expensive), but then I can't keep the lenses.

[vinyljunky]

I'll stop by TST service center to get it looked at. I was interested in upgrading the body too, so if I go that route then I need to find a suitable replacement.

Tin Cheung said they would give me $1000 for my 40D (lol), but I'm not sure what body to buy. I'm losing faith in canon and would like to switch to Nikon, (or Leica if the m9 wasn't so damn expensive), but then I can't keep the lenses.

I'm not too sure about digital, but if you're going the film route I have a Mamiya 645 in excellent condition here!

[huja]

I'm losing faith in canon and would like to switch to Nikon, (or Leica if the m9 wasn't so damn expensive), but then I can't keep the lenses.

Nikon D800 is suppose to be spectacular . . . I wouldn't worry about selling your glass. Lenses retain their value far better than camera bodies. BTW, what do you have? Someone was looking for used Canon glass on GeoExpat this weekend.

[BaconBreadBaker]

But I'd have to sell the canon glass as it won't work with the Nikon, right?

I have 3 canon lenses:
10-22 f?
17-55 f2.8
24-105 L f/4

Not a great collection, but it's my start that I'd prefer not to need to rebuy everything

[threelittlepigs]

Test the body with each lens to see where the focal point is - a simple way to do it is put camera on tripod 8' to 10' from target (box of cereal for eg). Select centre point, one shot focus. Have a ruler in the frame at a diagonal to the target. Focus on the target using centre point only and where the target meets the ruler should be in focus. If another point on the ruler is in focus then you will know if lens and body are front or rear focusing, and by how much.

Another way to do it is to have 7 boxes each about 1" further from camera, starting from about 8' away. Focus on the middle box and if another box is more in focus you will know if camera is front or rear focusing. Shoot at the widest aperture. Also manually focus one shot as a baseline. Remember to use tripod to eliminate handshake from equation. If tripod is not availabale shoot at a high enough speed to eliminate handshake (eg 1/250th second or faster). Try at different focal lengths but try to fill the screen with the boxes (ie don't make it a small target).

After every shot, twist the AF ring and make the camera re-AF again.

Once you have your sample of test shots, bring body and lens to Canon service centre in TST and show them that the combo is either front or rear focusing and tell them to recalibrate. They should be able to recalibrate the body, lens or both. Go home and retest after recalibration. Hopefully by doing so you will have a very good AF camera.