Why do lens caps fall off so easily?

[Glenn NK]

"Why do lens caps fall off so easily".

I'm starting to suspect that they weren't put on tightly in the first place. I push the cap on, then give it a bit of a clockwise rotation until it gets a bit harder to turn.

The only lens cap that I had that "fell" off was when I dropped the camera/lens onto a hard floor surface from about a metre (3 feet). It also has a chip on the edge but it still works. Camera and lens OK, but the filter was a mess of shards.

Glenn

[Benjy]

I put a small piece of matchstick in the springy bit inside,seems to have one the trick.....

[loosecanon]

Its all because its old technology, if we started from scratch then the whole design would be different. The screw filters are made thin so as not to vignette the image, so filter depth in minimised, so lens caps clipped to filter threads fall off more readily. Lens filter screws are also minimised to lessen the gap from lens to filter, and minimise that perennial problem, the stuck filter.

Incidentally, how many use double sided tape inside the cap on the body end of the lens to catch dust etc sucked into a lens in use, before it works its way the the camera sensor.

[shreds]

Never lose the front caps and they stay put (Nikon pinch caps). Mine just sit in my back pocket until the end of the shoot.

For some reason the rear bayonet caps though repeatedly detach themselves in the camera bag.

I could cite many pro's who dispense with all lens caps altogether as has been said.

Absolutely detest bits of cord holding the lens cap as it just dangles and clatters free and is totally annoying.

[Richard Benish]

Two words: bad design.