I am a somewhat paranoid person when it comes to expensive things.
I am about to buy my first telephoto(70-200mm f4 L in case you are wondering). This lens is much larger than I am used to wielding(I normally walk around with a 50mm prime). My concern is that with this new size and weight of lens, I will accidentally break it. So I have a few questions about dealing with this. I should mention that my body is a Canon 450D(XSi).
When shooting with this do I need to worry about supporting the lens? If I am hand holding, I will normally have my left hand on the focus ring, but do I have to take any special precautions of supporting it? I don't want to accidentally damage the connection to the body.
Does leaving this lens on the camera make it unreasonable to wear with the strap? I currently use the strap that came with the camera, but I worry with this heavier lens it will make the camera off balance and uncomfortable to wear like this. In particular, I will be doing a LOT of hiking on a coming trip. Will this be uncomfortable?
If I have a body mount for my tripod will this lens be too heavy? I see that the larger lenses come with special mounts, should I look into getting a mount for this set-up?
Will carrying a larger lens like this through security at an Airport (domestic and international) cause me any grief? I intend on carrying-on my camera gear, but how best to deal with this? (Maybe this should be a separate question, I'm not sure.) EDIT I have received some great answers already, but I should mention that a backpack camera case is not possible for me, since I will be backpacking and thus be carrying a full pack. For a camera case I will have to use some sort of shoulder bag, or find something I can connect to my main pack.
I hope that the above is clear. Ideally I would like comments from those who have experience with this lens, or lenses of similar weights (705g) and lengths (172mm), and similar body types.