[GatorPentax]

I have the opportunity to buy a 135mm f2.5 SMC lens. I hear its rated very high in terms of contrast, sharpness, and bokeh. My concern is that i have no experience with screw mount lenses. I know i need an adapter to fit the K-mount k10d but does anything deteriorate in the process in terms of picture quality? Im assuming that the adapter essentially turns the lens into an "M" lens where i have to manually adjust everything, am i correct?

Thanks

[-=JoN=-]

pic quality doesnt change any since it's just a bracket your screwing on to the lens so that it mounts on the k10.....

aside from that..shoot as if you have any other manual lens...

also the cheap ebay ones......doesnt screw all the way..so you might lose infinity focus





here's a shot w/ a super takumar 135mm, screw mount
on a k10

[FotoPete]

Nop, there's no real deterioration.

Just screw on the adapter, mount the lens like you would a K Mount lens. Twist till the adapter locks and shoot away.

You'll have to use stop down metering. Cuz the aperture is not linked, you'll have to focus, then stop down, and then shoot.

[Canada_Rockies]

The mount adapter K allows you to screw your M42 lens onto the K mount camera (any) and it will focus to infinity. All other functions become manual. The lens stops down as soon as you turn the fing (stop down metering) unless it is an even older preset lens with two rings.

Check this and other forums (fora?) for problems with some of the off brand adapters. I never had a problem with my Pentax branded one.

[GatorPentax]

wow thats fast replies. I love this forum. Thanks everyone. So would it be correct to assume functionality like an M lens? where the aperture ring is manual and not connected to the camera but i still control exposure time on the body? IF thats all it is, thats great! i love using M lenses and the manual aperture controls is just a minor hiccup....although those pesky "A" lenses sure are nice.......and expensive!!

[GatorPentax]

BTW, thanks for those pics Jon, the words beautiful and simply amazing comes to mind. The bokeh is buttery smooth

[FotoPete]

Make sure you get the pentax adapters that sit flush with the K Mount plate. Otherwise you'll lose infinity focus.


Third Party and Pentax Brand


How it looks mounted.

[Mike Cash]

They're not quite like M lenses. The difference being that you can shoot in Av mode and have your metering done for you by the process of setting your aperture. You don't need to push an extra button to meter.

[rdrum76]

Thanks for AV mode tip