I was just playing with an old manual focus lens of mine. It's a Cosina-made Vivitar 135mm f/3.5 with K mount. There's the AUTO text in front of the lens and I can't figure out what it means. This is of course not an AF lens. There's no A setting either and my K200D does not recognize the aperture used. And AFAIK, this isn't a Ricoh lens, so no Ricoh-specific automagic either.

So, any idea what the heck does the AUTO on this lens mean?

Oh, boy, I should've searched first.

https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/79442-what-doe...us-lenses.html
https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/50626-auto-lenses.html
https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/47213-auto-manual-lenses.html
https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/96172-vivitar-auto-telephoto.html

[axl]

If you are not bothered to read provided links, here's short version as I understand it:
Manual "auto" lenses have diaphragm linked to the body by lever, which enables wide open focusing and automatically stops the aperture down to value set on the ring when the shutter is pressed.

[Blue]

Basically, your lens will work like the M series lenses or earlier K series lenses when using them on your dSLR.

Edit: Auto was originally used to describe lenses in the late 50s that had the capability of stopping the lens down at the time of shutter actuation. Then along came the A series lenses in the mid-80s that allowed program cameras to read the setting etc. That was followed by AF/auto focus. I won't bring up semi-automatic lenses.

[Ira]

You'll always get F-- in the viewfinder with it, but it won't flash and you can use it in M mode if you have ""Use aperture ring--permitted" in your settings.

Thanks, guys. I actually browsed through those earlier threads after I'd posted this one. I should've known it wasn't such an original question as I originally thought and should've searched before posting.