Why can't I shoot in lower f stops (must b on f22) on my?

The camera (Nikon D3000) forces me to lock the lens (older AF Nikkor 35-135 mm lens) on the highest f22 stop for it to shoot. I realize the camera is a DSLR, and the lens, while in brand new condition, is around 20 years old. I focus manually and I thought I would be able to set the aperture manually as well, but like I mentioned, the camera will not shoot unless the lens is locked at the highest f22 stop.Am I missing something or is this it?

By using the control wheel on your camera, you can adjust the lenses aperture. Locking the lens aperture at f/22, tells the camera what the smallest possible lens aperture is, but using the control dial you can adjust the lens aperture in either the manual or shutter priority mode

By the way. F/22 is the smallest aperture. Larger apertures are f/5.6, f/4, f/2.8 etc.

On a Nikon autofocus slr or dslr, "locking" the aperture ring at the lowest f-stop does two things. First, it allows your camera to utilize the full range of f-stops of the lens. Second, it couples the lens with the command dial on the body, where you can select the aperture of your choice.

In fact, most newer Nikon lenses are "G" lenses that don't even have an aperture ring.

With the correct ISO, lighting, and shutterspeed, you'll have the full range of apertures available for you.

Why can't you read the instructions that came with your camera?

All Nikon "D" lenses with an aperture must be locked at f22 for the camera to adjust the aperture.

In a way, the lock position at f/22 is the "auto" position, and the camera's exposure system will change the aperture to what it needs to be when you are in Auto, Program, or Aperture Priority, as long at the aperture is locked.

So even though the aperture ring says f/22, if you set the aperture to say f/8, it will go to f/8 when you depress the shutter (in Aperture Priority mode).

Think of f/22 as a combo position; f/22 and "locked for camera auto control".

If you put the camera into Manual mode, you can then adjust the aperture via the ring.

Manual focusing is different from manual shooting mode. On a dSLR, the correct way of adjusting aperture size is through the camera body (using the wheel), not on the lens. Keep the lens aperture ring set at largest f/number (f/22 in this case) and lock it in if possible. The camera needs it set that way so it can take control of aperture settings.

In A mode, turn the wheel (under your thumb) to change aperture size. In M mode, pressing the +/- button will toggle wheel control between shutter speed and aperture size.