So after much internal debate, I think I've settled on taking a 70D, 18-135 STM, and a single prime in a 4 million dollar home for a cruise to the Caribbean. I'm trying to figure out what I want the prime to be. Now I've chosen the bag as it's on the upper limit of what I want to carry. I chose the 18-135 for the wide focal length, STM motor for video, and I already own it.
The real lacking part of the kit is it's obviously quite slow. So I'd like to pair a reasonably sized prime with it for low light situations. I own the 40mm pancake and the canon 50 f/1.4, however I'm thinking the 50 would be too long for most things indoors on the cruise ship, and I'd like something faster than the 40. I keep thinking about the 35 f/2 IS. It is 3 stops faster in IS situations and only 1 stop slower than all the 1.4 options. I could really see this being useful for taking night shots of ports and such given I won't be taking a tripod.
The 35 f/2 IS is a 67mm filter which would let me share a CPL with the 18-135. I don't plan on taking my ND filers (though I love them), without the tripod, I don't think it makes much sense to take them.
One of the other obvious lenses would be the S 18-35 f/1.8, however it doesn't share a filter with the 18-135, it's twice as heavy, twice as big, and doesn't have IS for night time hand held shots.
Are there any other options I'm not considering or things I'm putting too high a priority on?



