Filters?

A lens filter is not used as a protective cap. If you use a filter, you put the lens cap on the filter to protect the filter. I think what you are looking for is something like this fast cap. You can flip it open and closed.
OP/TECH USA FILTER CAP 58mm 0701581 - B&H Photo Video

 

Lots of helpful discussion in this thread https://www.mu-43.com/f67/filters-639/ all about filters

 

The above mentioned thread has lots of previously discussed things about filters so it's a nice read albeit a little long.

I use a lens filter as a protective cap. From what I recall reading on that thread, I think there's quite a few other people doing the same too.

I see no real drawback in using it as a protective cap, they are quite durable, scratch resistant, and easy to clean so I can just wipe the lens filter with what ever and not really worry about it. On the off chance the lens filter eventually gets scratched.... it's about $15 to $20 to replace (at least for the ones I use, HOYA HMC clear or UV(0) filters).

Come to think of it... I don't even know where my original olympus plastic cap is anymore... I'm sure it'll pop up some where.

 

The B&W MRC UV filters are very good. A little pricey though. It was $38 for my E-PL1 kit lens.

What do you find annoying about putting a lens cap on a lens? When I'm out shooting I put the cap in my pocket then put it back on the lens when I'm done.

 

My friends are recommending the use of lens hood to protect...so I started using them...by the way my Lumix 14-140mm and Zuiko 14-54mm also came with its original hoods...

 

i also just use a UV filter to protect my lenses - the caps are sitting in a pile in the cupboard somewhere. i got sick of putting the cap on / taking it off / putting it on again when on holiday... when an opportunity presents itself you have to act fast!!