I'll apologize in advance for this, but I'm stuck as to what, if any, other lens I should be looking at for the olympus em1 for travel. I'm currently using the 12-40 f2.8 and we head to vietnam/cambodia in october for 3 weeks. I'm not sure if I should be looking at a wider angle for landscapes (which I intend to take a lot of photos of) or something longer like the 45 1.8 or 75 1.8 for portrait shots of some of the people of those countries. my main concern was weatherproofing as I believe it could be quite wet in the middle of the country at least at that time, however with the 12-40 I can always put that on the camera if it's raining. I really want a sharp lens, I have the 40-150 4.0-5.6 and frankly I'm unhappy with the photos I've got using it. I really would like to limit the amount of lenses to carry as we're backpacking, but I'm unsure of which to look at. Ideally I'd prefer to keep the cost under 1k for another lens, but have looked at the other two pro lenses, although the f2.8 makes me wonder if I should look at a prime for low light. totally torn here. any advice?