Most lens caps will have 2 points you squeeze and then place on the front of the lens. If the lenscap does not fit the lens check the following:
- Are you using the correct lens cap? The lens cap size is determined by the filter diameter of the lens. You will find this noted on the lens or in the specifications for the lens.
- Is there a filter mounted on the lens? A filter may not have enough filter threads on the outside to mount a lens to.
- Is there any other type of accessory, such as a filter step down ring, attached to the lens? Any external accessory could affect the the ability to mount the lenscap.