Originally posted by Adk X .. I think maybe the lens I bought will not Beep or give me the focus dot in the viewfinder because it is below a 5.6 (it's a 2.5 )...I read in the back of the manual last night around 1:00 AM in a lens compatability chart that certain functions will work on certain old manual lens of only 5.6 or faster.I have a 135mm 2.5 km.Will call B&H today.THANK YOU SPECIAL K
I also have an old M 135/2.5 and it works fine on my K-x and K200D, and I am VERY confident that lens will work 100% fine on the K-5. I wouldn't rush to return it to B&H, but rather take a moment to make sure you are using it properly on your camera.
On my Kx/K200D the focus dot appears no problem at all.
To use older manual lenses on modern Pentax DSLR's, as p339 of the K-5 manual says, you need to make sure you have the 'Using Aperture Ring' setting set to 'Permitted'. [Menu > Custom Settings > 27. Using Aperture Ring].
Then:
- set the lens aperture wide open or to 'A' if the lens has that setting,
- put the lens on the camera,
- the camera will then ask what focal length the lens is (for SR to work),
- set the camera to shoot in Av or Manual mode (preferred), and then
- before you take a shot, press the green button down briefly to get the camera to set the metering for the aperture or shutter speed you've selected (per p-102 of the manual), or do a DOF preview.
By default (I think) when using manual focus lenses the 'in-focus' AF confirmation indicator will only work in centre-spot mode, so that's where to look for your focus target.