Focus issues & MA: Why send it for calibration?

I've read a lot of posts that say something like: "I have to set my (insert lens here) to +9 MA, so I'm sending it in for calibration."

I don't own a camera with MA, but this seems strange to me. If you can MA a lens so it focuses accurately, what's the point of sending it in for calibration? MA is there so you don't have to get the lenses fine tuned for AF at the service center, and more importantly so you can fine tune them to your particular body. Right? Like I said, I don't own a MA body, so I'm speaking outside my own experience.

I wondered that too until I heard folks talking that even after MA that the lens would still be OOF at different distances than where the did the MA or at different FL on a zoom.
If MA works, great. If it only works at the MA distance/zoom then not so great.

My general opinion is that MA is not as useful as a lot of people expected. Zoom lenses in particular often cannot be corrected with MA as they want different amounts and directions through the zoom range.

All that said, if I owned a lens that worked absolutely fine for focus despite needing a large amount of MA, I would not sent that lens in for adjustment. I don't fix what isn't broken.

Can't you set MA for different focal lengths? Or is it only one general MA-setting for the whole range and specific lens?
Though i guess if you need to set it at different focal lengths to get it corrected, then i would assue it really needs to be calibrated?

Or what are your thoughts about this guys?

MA is helpful, but far from a cure

As mentioned, issues like distance, focal length

I recently purchased a 5D but it's useless with my 85L as it just back focuses, and without MA, I would need to pay over $200 to get them calibrated to each other (thereby taking them out of sync against my other lenses)

I wish canon would extend the functionallity of the MA on the cameras that support it so that you could add MA to different focal lengths on the same lens... That would be neat!

M.Quick wrote in post #11839691
I wish canon would extend the functionallity of the MA on the cameras that support it so that you could add MA to different focal lengths on the same lens... That would be neat!

Don't know how pratical that would be to implement or how much skill the photog would have to have to do the multiple MA, but it is a nice "wish list" item.

If MA cures focussing accuracy at all distances (taking in to account the occasional focussing error that does happen, particularly with very fast lenses), then there's absolutely NO NEED to send it for re-calibration to Canon. But as others have said, if it's still very erratic then it's best Canon have a look. My 24L f/1.4 II needed +12 and 85L f/1.2 II needed +7, well within tolerance so I felt no need whatsoever to send them to Canon.

Lenes / Cameras should focus correctly out of the box from manufacturer.
Adjusting a lenes / camera with MA makes about as much sense as adjusting
your auto engine to run to the automakers specs.

EL_PIC wrote in post #11839828
Lenes / Cameras should focus correctly out of the box from manufacturer.
Adjusting a lenes / camera with MA makes about as much sense as adjusting
your auto engine to run to the automakers specs.

I suggest you read these then if you think every lens and camera body should be 100% accurate out of the box;

http://www.lensrentals​.com/news/2008...nd-other-myths

http://www.lensrentals​.com/news/2010...nd-other-facts

EL_PIC, I wish you were CEO of Canon Inc...alas it is not so

EL_PIC wrote in post #11839828
Lenes / Cameras should focus correctly out of the box from manufacturer.
Adjusting a lenes / camera with MA makes about as much sense as adjusting
your auto engine to run to the automakers specs.

I wish you where right, but unfortunately you're not. There is always gonna be room for error, no matter what you buy. Some has more and some has less product errors than others.

In the perfect world you would be right, but it's not..

EL_PIC wrote in post #11839828
Lenes / Cameras should focus correctly out of the box from manufacturer.
Adjusting a lenes / camera with MA makes about as much sense as adjusting
your auto engine to run to the automakers specs.

I would actually like to know the percent of "out of spec" lenses/cameras that each manufacture puts out.

We hear about problems on POTN, but how many are there really compared to the equipment built?

I know that all of my lenses have been good out of the box as far as focus is concerned.

Not even one has MA. You can only adjust a zoom for one mm setting. You can only adjust one lens for one distance. And if your MA reuires a lot of adjustment - i.e. at the end of the scale you have, what will you do when it changes and it can? Many just feel better having the experts adjust it like it should be.

guntoter wrote in post #11840222
I know that all of my lenses have been good out of the box as far as focus is concerned.

Out of all my lenses, all require MA except for my 100 mm Macro, because I use it in Manual Focus mode

My 85 f/1.2, 35 f/1.4 and 200 f/2 are the most annoying