If it is a Pentax mount lens, it will work on your K10 and your DL. The one caution is with the Ricoh mount which may have a pin located where the autofocus drive is on the camera body. An examination of the mount before putting it on the camera is a good idea. It is apparently a real problem to get the lens off if the pin goes into the drive screw hole. Most on the list remove the pin, and a search of the fora will find a number of helpful threads for doing this.
I have a K10, and have never owned another Pentax digital camera, but can walk you through the steps for using any pentax lens on the k10D. You will need to use the manual for the DL to work through the equivalent steps.
There are four broad classes of mount. The good news is that each and every one of these lenses can be used on your digital camera.
- Autofocus lenses - F, FA, DA, etc.
No problems with these lenses at all. They all work the same. Just make sure that the lens aperture ring is set to the "A" position. - Program autoexposure lenses - there is an "A" position on the f/stop ring.
These lenses do not focus themselves, but all exposure modes are available as long as the lens is set to the "A" position. - Manual f/stop only - No "A" position on the f/stop ring.
- Matrix metering is not available. If the camera is set to matrix metering, it will use center weighted metering instead. On the K10, Spot metering is also available.
- Only the M, X and Av modes are available.
- Av mode will autoexpose, but the lens will remain wide open. The aperture ring is ignored.
- X mode is M mode with a fixed shutter speed of the flash synch setting 1/180 sec.
- M mode requires a change to the custom menu settings. Change [Using Aperture Ring] from [Prohibited] to [Permitted].
- Use either the green button to let Mr. Pentax set the shutter speed for you at the aperture you have selected, or
- Use the Depth of Field Preview position on the on/off switch. I prefer this. It gives the under/exposure scale in the viewfinder and on the top LCD. It is an interesting bit of finger work, but works quite well.
- The problem is that the exposure may not be correct when you use either of these methods of determining the correct shutter speed. I found, for example, with my 400/5.6 M lens that I must use the apertures between f/8 and f/16 to get an accurate reading. I have yet to "calibrate" my 100/4 macro M series lens. You will need to try the lens on the camera and see where the metering works. Then you can adjust the settings to what you need for the shot.
- Screw mount lenses work the same as the K and M series, but require an inexpensive adapter to mount on your camera. I would recommend only the Pentax brand to be sure that your lens will focus to infinity and that the adapter is easily removed from the camera body. Some screw mount lenses that had an electrical connection to the camera, and they require some fiddling to work properly. Your best bet here is to search for threads on using screw mount lenses. I have used the adapter and screw mount lenses, but only on a manual exposure KX camera, and then I had only preset aperture lenses.