| I think you should get the 50-135mm for the uses that you stated. After playing around with my 50-135mm for a few days, I noticed that 70mm was really tight for crowded areas such a tourism. I am not sure about street photography, but the wider is usually the better (heard 35mm (normal) range is the best). As for landscapes, the 70-200mm would probably suit you better, but then again, you already have the 70-300mm for that.
A big consideration is if you can handle the weight of the 70-200mm as well. This was a big consideration for me and that's what swayed me to getting the 50-135mm.
1. if you THINK it's heavy, you won't want to use it as much
2. if you don't use it as much, you will be lazy.
3. If you are lazy, you won't take good photos.
:-D |