Canon 24mm/2.8 IS USM vs. ???

maxx32 wrote:

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The goal here would be a smaller/lighter 6D+lens combo. (I understand that I am giving up weather sealing and would have more lens swaps to manage)
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I do not own this specific lens, so I will only answer to one of your questions...

If you are looking for a lightweight kit, I'm not sure that the difference in FOV between the 30mm you already own and the 24mm is so worth it to carry around both. Let's be honest, I'm a compulsive owner of lenses, so I do not mean you shouldn't buy one!
But, if you'd like to carry around a limited number of lenses (otherwise the zoom becomes a better solution to stay light ;), only wide angles might not be enough in much situations. Considering the lenses you already own, I'd rather think to a longer portable lens before to build a twins wide combo. What about a 50mm STM (very light and cheap) or even better an 85mm (a bit heavier but more useful when you look for something longer than 30mm)?

In the other hand, if you are searching for a lightweight alternative to your 30mm, then probably the 24mm will perfectly do the job. In such a case, I'd recommend you to pair it with a 40mm, which stays in any of your pockets, offering you a very nice and portable kit.

I assume here you don't look for L lenses, as otherwise the weather sealing is present on a marvelous lens called EF 24mm f/1.4L II No IS but with an f/1.4 you'll often won't miss it...at least, I do not!

Hope those thoughts helped you somehow...