I tried out the this lens on Pentax K-x White. The lens has Ricoh P pin and the aperture ring has the P selection for programmed mode in Ricoh xr series of cameras. The lens works fine on Pentax digital bodies without any pin stuck issue as I have explained in my earlier post about Rioch P pin
- P pin tip is found a rounded ball-head type
- P pin is small and that when you use your thumb to glide over the pin, you don't feel it sticking out upon pressing it down
- P pin is found retractable
When mounted on Pentax K-x, it works as a Pentax K manual lens. I have to use green button for stop-down metering. There is the undocumented observation about K-x in working with green button on K lens, it has an extra mirror slap that goes with stop-down metering operation. So far, I have not found a clue why the mirror slap is required in the metering.
In actual use, the extra noise does bother me a bit as every green button will have the extra noise on the mirror slapping. I ran few test shots on the lens with stop-down metering, they are not too bad. The lens is all plastic but I find it resemble closely the lens from Cosina.