I have just found an old F100 with a 28-200mm lens and it doesn't want to focus 100%. And when i develop the film it comes out a bit blurry as well, objects comes out but not sharp at all. When i look through the viewfinder the sharpness isn't that good either, i've played with the diopter which improved it to about 90%.

Any ideas on whats going on other than to take it in for a service?

BTW, i can't seem to get the lens to use multi AF, i can slide the switch to it but the AF points doesn't show up and neither can i manually pick the AF point i want can only use it in centre AF. Is this supposed to be like this?