It's Not Supposed To Be An AI Version, But It Is

[Matthew Currie]

The lever filing issue interested me, so I dug in my pile of lenses.  Some of the oldest ones show considerable wear,  but the newer ones almost none.  I enclose a shot of a selection. 

The 400/5.6 AI has a long lever that moves in a visible arc, lots of wear, no filing evident.  An ex-LA Times workhorse bought from KEH as bargain grade long ago.

The 35/2.8K pre-AI shows lots of wear, no filing but suggests why one might want to file it, if the dent becomes deep enough to catch. 

The 50/1.4 pre-AI was bought new in 1970 and certainly has never been serviced.  It looks to have been filed, though.

I don't know what it all means, but thought it interesting.  None of my AI, AIS, or AF lenses show any sign of filing.

[basker]

...One of these days I need to compare it to the 300/4 PF which is smaller and lighter, but you never know how the IQ will compare.
Plus the mechanics of the /4.5 ED lens are great.

That would be a difficult choice. Good thing that you are nicely covered while you decide.

Sam

[basker]

...The 50/1.4 pre-AI was bought new in 1970 and certainly has never been serviced.  It looks to have been filed, though...

Matthew,

Thanks for the information you posted. I was especially struck by the comment quoted. Perhaps the older lenses were "hand tuned" or maybe it was done pre sale. Either way it has given you an impressive service life.

After wondering how many ways these modifications can be explained, showing up on a new lens adds possibilities. Do you have any ideas about why it was done? It seems unlikely that a new lens would need to be filed to repair uneven wear.

Sam