We all know that many new Canon lenses, L lenses too, can have a plastic-made filter thread.
But even aluminium threads are quite fragile.
So, in order to protect them, I usually buy the cheapest filters available, remove (destroy) the glass element, and screw them on my lenses. Out of experience, I can say this saved my 24 TSE II from a major damage, when I stupidly dropped it on concrete...(had to send it for repair nevertheless ). Of course, I do use lens-shades, but some are to voluminous to keep mounted on the lens in the bag (24 TSE !)
But even aluminium threads are quite fragile.
So, in order to protect them, I usually buy the cheapest filters available, remove (destroy) the glass element, and screw them on my lenses. Out of experience, I can say this saved my 24 TSE II from a major damage, when I stupidly dropped it on concrete...(had to send it for repair nevertheless ). Of course, I do use lens-shades, but some are to voluminous to keep mounted on the lens in the bag (24 TSE !)