In reply to Kai:
If I'm using M43 on a day out I may have a 12-40 2.8 which would stay on for the day (or a Panasonic 15mm 1.7 which is an ace lens) I would also in a small neoprene pouch carry a 9-18mm wide angle, however changing lenses frequently mid route is not recommended. I'm used to changing lenses on photoshoots especially when using primes however you will be cleaning your sensor a lot and editing out dust spots and in this situation I'm not part of a climbing pair and even then juggling lenses is still a bit twitchy (I Use a Lowe pro sling shot in this situation).
A little photographic pre visualisation before setting off on a pitch can allow you to make lens choices in advance. Certainly getting good shots as part of a roped pair is very challenging, again on the mountains ridges and traverses will help with this so a bit of pre planning ie what's the background like (wide or tight) when is the traverse coming up etc.
The 9-18mm is super compact and fits in a very small neoprene pouch and will fit in a chest pocket or hang off a harness, but obviously depending on how thrutchy you get it will be vulnerable. Amazon was a place to get the neoprene pouches.
The Peak Design capture clip is good for the mountains up to easy scrambles, but not for climbing.
I will be putting together an article on carrying photography equipment in the mountains/climbing at some point soon.
Post edited at 07:08