A lens cap offers protection for your camera lens. It’s a good idea to keep the cap on when your camera isn’t in use.
If you use lens filters with your camera, you may wonder if a lens cap works with a lens filter. In most cases, the answer is yes.
A camera lens has a front thread to allow for easy attachment of a lens cap. This is suitable for a snap-on, push-on or proprietary cap. Similarly, a lens filter also comes with a front thread for easy lens cap attachment.
Using different filters
Of course, when using lens caps with lens filters, use the correct size so you get a perfect fit. If you use UV filters, CPL filters or fixed ND filters, look for the ø symbol on the cap of the lens and the filter. Make sure that the sizes correspond with each other.
If you use variable ND filters, the cap needs to be a size bigger than the lens filter. The reason for this is that these types of filter are made from two layers of glass. The top layer of glass is bigger to avoid vignetting. For example, if your variable ND filter is 67mm, your lens cap should be 72mm.