ohchengyu

From what I know, PZ-1p and MZ-S have mirror lock-up with two second delay and all the other features.

Since your camera is not a DSLR, it is quite unlikely for dust to land on the sensor. You should check that the front lens element is clean from dust and fingerprints.

 

Another possibility is that the lens elements have been misaligned after a strong impact or the autofocus system is malfunctioning. You would need to take the camera for servicing to check for the last two problems.

If the lens is able to mount on your camera, it is a pentax mount. Check that the lens has an 'A' position on the aperture ring and set it at this 'A' position. The aperture is then set on the camera body via a dial.

 

This issues occurs with some Pentax SLRs like MZ/ZX-30/50/60, *ist, that lacks a coupling to read the aperture the lens is set at and requires an 'A' on the aperture ring to work at a non wide open aperture.

If you are on a budget, you can consider the Sigma 70-300 f4-5.6 APO or Tamron 70-300 f4-5.6, both with 1:2 macro at the long end. For Pentax, there is the 80-320 f4.5-5.6. More expensive choices are the Sigma 70-200 f2.8 EX and Sigma 100-300 f4 EX.

I would advise you to go out shooting with your 28-90mm lens to find out what focal lengths you use most. You may find yourself wanting a wider angle of view or a longer one. After this you purchase a wide angle zoom or telephoto zoom depending on your needs.

Do you have any other lens to try on the ZX-L to see if the metering works? You could try cleaning the electrical contacts on the lens and ZX-L lens mount.

I think the best AF would be the MZ-S which uses the SAFOX VII. The *ist, which uses the newer SAFOX VIII, look sbetter on paper but it seems from what I read that the MZ-S has an advantage in low light.

I own the new Tamron 28-200 with 62mm filter. I am quite satisfied with it and would recommend it if you are looking for a 28-200 zoom. There is noticeable pincushion distortion from about 50mm to 200mm, image quality is slightly weak at 200mm f/5.6.

 

For two zooms covering the range, you could look at a second hand Pentax 28-105mm f4-5.6 which has powerzoom or the new pentax 28-105mm f3.2-4.5. The Pentax 28-105 f4-5.6 with IF is a Tamron. For a telephoto zoom, there are the Sigma/Tamron 70-300mm with macro at 300mm. The price of these two lenses from 28-300 might exceed your budget though.

There are much fewer zooms for the M42 mount than K Mount and the few M42 zooms do not have large zoom ranges or wide angles to telephoto like 24-105mm. In K Mount, there is the Pentax 24-90mm f/3.5-4.5 and Tamron 24-135mm f/3.5-5.6.