Using Older Lenses with PENTAX DSLRs
Q: Can I use older PENTAX lenses on my DSLR?
A: Yes. (These steps may vary slightly depending on camera model). PENTAX A-series lenses (with an "A" setting on the aperture ring), can be used as manual-focus lenses in all exposure modes on a PENTAX DSLR. PENTAX K-mount, M-series and S (screw) mount lenses without auto-aperture control (an "A" setting on the aperture ring) can be used in Manual exposure mode using stop-down metering and manual focus. This is the exposure mode which will give accurate exposures when using these older lenses on our digital SLRs. If older lenses without an "A" setting on the aperture ring are used in Av (Aperture Priority) Mode, an exposure error may occur. Note: Using PENTAX S (screw) mount lenses on a PENTAX DSLR requires the use of a Pentax Mount Adapter B. To set up your PENTAX K10D, K200D, K20D or K2000 to use older PENTAX lenses: Press the Menu button
Go to Custom Settings
Step down to Green button in TAv & M (K10D/K20D). (this step N/A for K2000) Step down to Green button in Manual (K200D) Press the right arrow and select Tv Shift
Press OK (This setting allows easy and accurate exposure metering using older lenses without an "A" setting on the aperture ring. When the Green button is pressed in Manual exposure mode, the lens "stops down", the camera's meter measures the light passing through the lens, and an appropriate shutter speed is automatically set based on that measurement).
On the K2000, pressing the Exposure Compensation button (the +/- button) will automatically set an appropriate shutter speed in Manual exposure mode when using non-"A" series lenses. Step down to Preview Method (this step N/A for K2000) Press the right arrow and select Optical Preview
Press OK (This setting enables the camera to "stop down" the lens to a selected aperture when the On/Off button is rotated clocwise). Step down to Using aperture ring
Press the right arrow and select Permitted
Press OK. (This setting allows the camera to operate with older K-mount or S-mount lenses that do not have an "A" setting on the aperture ring). If Shake Reduction is enabled when using an older lens, you will need to manually select the closest matching focal length from the Shake Reduction (K10D) or Input Focal Length (K20D/K200D) menu. Press the Menu button, step down to Shake Reduction (K10D) or Input Focal Length (K20D/K200D/K2000) then press the right arrow. Scroll left and right to select the closest match for the focal length lens you are using. Press OK, then Menu.