Pentax K2 K2 Manual - Page 32

Open-aperture SMC Pentax lenses have a diaphragm coupling lever 0 on the back of the lens which locks into the camera body to permit open-aperture metering. The super telephotos do not have a diaphragm coupler, so they must be used with the stop-down metering system. Use of the Auto-Extension Tube Set K permits open-aperture metering. It can also be set to stop down the diaphragm automatically. Use of other K Series accessories - standard Extension Tube Set K, Helicoid Extension Tube K, AutoBellows K and Bellows Unit K - requires stopdown metering. Whenever any one of these is used between the camera body and an SMC Pentax lens, the stop-down metering system must be used. A - 4 OPEN-APERTURE METERING LENSES SMC Pentax Fish-eye SMC Pentax SMC Pentax SMC Pentax SMC Pentax SMC Pentax SMC Pentax SMC Pentax SMC Pentax SMC Pentax SMC Pentax SMC Pentax SMC Pentax SMC Pentax SMC Pentax SMC Pentax SMC Pentax SMC Pentax SMC Pentax Zoom SMC Pentax Zoom SMC Pentax Macro SMC Pentax Macro 17mm 15mm 20mm 24mm 28mm 35mm 35mm 50mm 50mm 55mm 85mm 105mm 120mm 135mm 135mm 150mm 200mm 300mm 45 - 125mm 85 - 210mm 50mm 100mm STOP-DOWN METERING LENSES SMC Pentax SMC Pentax SMC Pentax SMC Pentax Zoom 400mm 500mm 1000mm 135 - 600mm f/4 f/3.5 f/4 f/3.5 f/3.5 f/2 f/3.5 f/1.2 f/1.4 f/1.8 O1.8 f/2.8 f/2.8 f/2.5 f/3.5 f/4 f/4 f/4 f/4 f/4.5 f/4 f/4 f/5.6 f/4.5 f/8 f/6.7 30.