How standardized are lenses?

[haempe]

Or differently asked, are the optics interchangable between the barrels of different lenses of the same typ?
For example, a Canon 50/1.8 with cosmetically/mechanically fine condition but scratched glass and another lens with rocked off barrel but nice glass.
Exchange possible without complex calibration?

 

[VinceC]

Usually the lenses were individually tested and shimmed in the workshop to compensate for variation.

 

[ferider]

Unfortunately, you'll have to re-collimate for infinity, at least (shimming).

On closer focusing lenses (like the DR Summicron) even the RF coupling would have to be adjusted. With the Canon, and its MOF of 1m, you'll be most likely fine with shimming only.

Roland.

 

[haempe]

Ok, thanks for the response.
Shimming would be possible, but the position of the individual lenses to each other remains as before?

 

[ferider]

There might be a small error at close focus, but with this lens, and on film, the DOF should cover it. You'll be fine, I think.

 

[haempe]

Thanks, Roland.
I think I'll venture a try ...

 

[ferider]

BTW, what do you mean by "rocked off barrel" ? If it's the black 50/1.8 you can change just the black focus grip, for instance.

 

[haempe]

Both are the early all chrome version.
Seriously dented filter tread, worn chrome and rusty, and the focus throw is stuck, seems warped or so...
I got it as "defect" for 10EUR, but has really good glass.