[pepeche]

Hi everyone. I am new to the pentax gear.
Recently acquired an old lens, its a 135mm f3.5 takumar.
Can someone explain to me why it has two iris rings at the end of it? Im terribly confused.
Any help is appreciated.
Cheers!

[elliott]

It is called a preset lens, one ring actually clicks, that is where you set the aperture you want. The other ring moves smoothly, you use that one to go between wide open and your selected aperture. This was before the automatic aperture pin on M42 lenses, so you would focus wide open and then stop down to shoot. They are very convenient once you get used to them, especially on non-M42 bodies that don't have the stop down pin.

[pepeche]

Thanks mate! That makes sense. Appreciate your help.