It sounds like the place you want to start is with getting a proper exposure with a manual (non-A) lens:
https://www.pentaxforums.com/forums/pentax-beginners-corner-q/110658-using-ma...x-dslrs-f.html
Lenses with the A setting will work in all modes. Lenses without an A setting will work only in M mode, but it is possible to have the camera calculate a correct exposure when you have selected the aperture. There are two levels of pre-A aperture control on manual aperture lenses:
#1 Full Manual: This is how all screwmount lenses will behave, and some manual aperture K mount lenses. When mounted, these lenses will always move the diaphragm as you adjust the aperture ring.
#2 Stop-Down Metering: This is how most, but not all, of the SMC-M series pentax lenses work, and most of the K mount non-A lenses that were produced. This lens will use the same linkage that the later lenses use for aperture control to stop down to the aperture selected on the aperture ring at only two times, either during an exposure, or when you press your depth of field preview button. This allows you to focus with the lens set at it's maximum aperture without racking the aperture ring back and forth between shots.
I used to have a K-r, and it doesn't have a true "depth of field preview" function, but in manual mode one of the buttons near the shutter (maybe green?) will briefly stop down the lens and take a meter reading when you're in M mode. This is what you want to do. If you have a #1 lens mounted, it will simply take a reading at the aperture you have selected. If you have a #2 lens mounted, it will stop the lens down to your selected aperture and then take the reading. Two things are very important to note: This method of metering doesn't require any communication of focal length, maximum aperture of the lens, or selected aperture. It's exactly the same as having the camera watch the needle meter on a K1000, and adjusting shutter speed until it's near the middle. This means you can use any lens that you can get mounted... pinhole, anything you can cobble together and get to focus. It also means that your teleconverter won't affect anything when using stop down metering. The second thing to realize is that you're using the light meter outside of the range that it's calibrated for. The light meter in your K-r is optimized to take a reading on A series and later lenses, where it will usually only have to take readings with an open aperture. In daylight, stop down metering works very well, but accuracy can suffer when taking reading in low light at small apertures.
Another thing to note when using any lenses KA mount and prior is that there is no communication of focal length to the shake reduction system. When you mount a lens that doesn't communicate its focal length to a Pentax DSLR with shake reduction, it will prompt you to enter the focal length. If you skip this step, and don't turn shake reduction off, you will end up with the sensor movement over or under compensating for your movement, and the results will not be as good as you've come to expect using the kit lens, or another lens which communicates it's focal length automatically.
Originally posted by xPremium 
Similar Threads 
