Originally posted by A guy with no plan I've solved the problem with the "Aperture ring" setting. I changed it from off to on , and now I can take pictures , however , on the screen I can't see the correct information of the aperture , but in the veiwfinder , I can see the F number properly.
But thanks for all your help , I very appreciate it.
Right. One of the first things I wondered about upon seeing your post, is what lens you are using. Are you using an old manual-focus only lens model? Which one? The fact that it has an aperture ring indicates an older lens design, but some of these offer auto focus (AF), while the lenses designed before AF became widely available do not.
It is normal with any Pentax DSLR when using the aperture ring to set aperture, that the screen will not register the aperture setting, while the VF will. When using the aperture ring to set aperture, you must shoot in Manual mode and achieve metering of your scene for exposure value by using the green button. You set the aperture, and with the green button the camera will set the shutter speed to a correct exposure value for the aperture you have chosen.
Your focus settings depending on the lens and what your use of it will be. AF-S for single shot shutter release, where the camera will not fire unless focus is achieved and confirmation is registered by the camera, shown by the focus-confirmation light, and usually accompanied by a beep. With AF-C, the camera will activate AF on a continual basis, adjusting the focus as the subject moves, and the shutter will fire even if accurate focus is not achieved. Then there is MF where you focus the lens manually, and the shutter will fire even if focus is not achieved.