Can I calibrate a lens myself?

[Patti Edens]

Help!

I noticed that my 3 year old Canon 100-400mm L with IS was back-focusing and sent it to Canon. Canon says that it has indeed "fallen out of calibration" and needs to be calibrated. The cost for this is $339.91. Ouch. It's all labor, tax and shipping - no parts.

I'd pay the bucks and get it done but this is the second time this lens has needed repair and the last one was almost $800 so I can't help but wonder what's next or if it will "fall out of calibration" again in a few months.

Can I fix it myself?

Any help, ideas or doughnuts would be greatly appreciated.

[JohnT]

Although I have no experience in this area, my thought would be no since it probably requires some disassembly and connecting to some sort of machine or computer.

[Patti Edens]

Originally Posted by JohnT

Although I have no experience in this area, my thought would be no since it probably requires some disassembly and connecting to some sort of machine or computer.

That makes sense. I have been googling for info but not finding much. Except that Sigma and some of the other manufacturers only charge around $50 to $100 to recalibrate lenses. I wonder if the high cost has more to do with the Canon name written on the lens or with the complexity of the lens.

Thanks John,

[venchka]

Is it time to stop the bleeding and find a different lens? $1,200 and mucho time away from home is a lot of bother for one lens.

[Patti Edens]

Originally Posted by venchka

Is it time to stop the bleeding and find a different lens? $1,200 and mucho time away from home is a lot of bother for one lens.

Yep. That is going to happen. Now I just need to decide whether or not to let Canon fix it before I sell it or just sell it as is. I don't know if I can get the $340 out of it or not. I wouldn't sell it to anyone without telling them it's back-focusing, so I probably couldn't get very much for it as is. I just hate to spend that much on a lens I know I'm going to get rid of.

[tjavery]

So you're $1200 + 800 into the lens already, and it's another $340 to get working right? That's insane. That's not what I'd expect from an L-lens. This is disappointing to hear.

Is there a lemon-law for lenses?

edit: Sorry, I assumed 1200 for the lens; I just realized they are closer to 1400 new!

[CaptainTom]

Is there a lemon-law for lenses?

only for anisotropic lenses...

[Patti Edens]

Originally Posted by tjavery

So you're $1200 + 800 into the lens already, and it's another $340 to get working right? That's insane. That's not what I'd expect from an L-lens. This is disappointing to hear.

Is there a lemon-law for lenses?

edit: Sorry, I assumed 1200 for the lens; I just realized they are closer to 1400 new!

Yes, I paid $1400+ for it with shipping. I wish there was a lemon law because this one is a definite lemon.

I wonder if I could just go buy a Mark III camera and calibrate the lens to the camera? Isn't that camera supposed to do that? I need to read some more.

The AF wouldn't work with my 20D but at least it would work with the Mark III. I'd rather apply that $340 to a new camera than to a lens I'm planning to get rid of. If I get the camera, then I don't need to get rid of the lens. Hmmmmm. This might work.

[Patti Edens]

Originally Posted by CaptainTom

only for anisotropic lenses...

Huh?

Please explain. Sometimes I'm a lot like my Mom. Dad used to say, "Don't tell her a joke on Saturday or she'll laugh in church on Sunday."

[carrbowl]

Patti, I talked to the guy I use for camera stuff, he said no one will calibrate it for you (that he knows of) except maybe Precision XXXX in Illinois and they will charge you about the same. That stinks...sorry to hear about that...that's alot of money to calibrate the lense..

[rogerfsmith]

There is one other very "cheap" option. That is to keep the lens and don't send it to Canon. Determine by testing how much it back focuses and then simply compensate. It may take you a few hundred test shots, but then you could fairly easy move the camera slightly forward or back, or twist the manual focus ring slightly in the appropriate direction.
I've had my share of bad luck with the Canon L lens myself and usually just follow my above advice for the ones I use.
cheers,
Roger

[Patti Edens]

Originally Posted by carrbowl

Patti, I talked to the guy I use for camera stuff, he said no one will calibrate it for you (that he knows of) except maybe Precision XXXX in Illinois and they will charge you about the same. That stinks...sorry to hear about that...that's alot of money to calibrate the lense..

Renae, Thanks so much for checking. I really appreciate that you took the time to do that.

[Patti Edens]

Originally Posted by rogerfsmith

There is one other very "cheap" option. That is to keep the lens and don't send it to Canon. Determine by testing how much it back focuses and then simply compensate. It may take you a few hundred test shots, but then you could fairly easy move the camera slightly forward or back, or twist the manual focus ring slightly in the appropriate direction.
I've had my share of bad luck with the Canon L lens myself and usually just follow my above advice for the ones I use.
cheers,
Roger

Roger, I didn't think of doing that, but I guess it would be better than just putting it on manual focus.

Thanks,

[Patti Edens]

I think I have the answer. I'm gonna get a 1D Mark III.

I found the owner's manual for the Canon 1D Mark III on line. It can compensate some for back or front focusing. The question I had was how much. So I did some more searching.

This White Paper on the Mark III describes what it is doing and how much it can compensate. It says that it can do 20 steps of compensation and 1 step is the single side DOF/8. I don't have a clue what they mean by single side, but if it means approx half of the DOF, then this will work.

[CaptainTom]

Originally Posted by Patti Edens

Huh?

Please explain. Sometimes I'm a lot like my Mom. Dad used to say, "Don't tell her a joke on Saturday or she'll laugh in church on Sunday."

Patti : It is in reference to TJavery's avatar.........
I have no idea why he uses that particular word, but a quick google search, and I increased my vocabulary by one word today....