so when you send a lens off because it auto focuses poorly...

[ride5000]

... what exactly do they "adjust" to make it work properly?

(i'm looking for a technical answer here, so don't hold back.)

thanks,
ken

[Karl Johnston]

Throw it in the heap, send you a new one :lol:

[ride5000]

:lol:

i guess nobody knows what they do, eh?

[chauncey]

It gets plugged onto a calibrated camera body and brought to specs at a specific distance.
The "specs" and "distance" is propiority information.

[20droger]

Like Chauncey says, but what they do is micro-adjust the focusing group's position relative to the rest of the lens. Zoom lenses are almost always adjusted at their geometric mean focal length, unless the complaint was about back/front focusing at a specific focal length.

[chauncey]

Can you expand on that a bit roger and, if you know, what do they do with bodies? :-?

[ride5000]

what i don't get is that we assume the AF sensor in the camera is "satisfied" with the focus, because it stops focusing.

but the image is really not in focus on the sensor/film plane.

this to me sounds like an issue of alignment in the CAMERA, not the lens... (ie lens-->af sensor not equal to lens --> film plane distance.)

put another way, if the lens is not focused properly, shouldn't the AF sensor detect it--and if it doesn't, how is that the fault of the lens?