Quote Originally Posted by John Koehrer View Post
LTM 50/3.5 Elmars used A36 slip-ons and the later version E39 filters.
With the A36 to adjust the aperture you must remove the filter or find the adapter that uses
an external lever that engages the aperture ring.
E39's have an aperture ring just behind the front group and accessible.
There is a second type of setting ring that lives inside the hood or filter next to lens to adjust aperture back off clamp screw and rotate filter or hood then tighten screw.
Invention of devil and the rings are collectible...
If you want photos the modern post 94 Elmar is comparable with late post 79 cron.
it us well compact collapsed with hood in place.
But a LTM Cosina /2.5 is only 1.5mm larger with hood.
And you don't need to extend or collapse.
Both have good ergonomics you won't tell the pics apart on 10x8s...