Beach shoot - couple of questions

I'm heading to the beach for a vacation next month and I'll have the opportunity to photograph my neices (7 y/o) cousins (2 y/o thru 13 y/o). I only get to see them once a year and some I have never even met so I'd really love to get some good photos.

I have a 40D and the nifty fifty and 28-135 IS.

I would like to have a new lens for kids pictures (running, jumping in the pool, etc) and I'll also use it for my dog playing. Any recommendations? I was thinking about the 70-200mm f/2.8L but my only concern with that one is the weight.

Is there anything I should know (yes I'm a noob!) about shooting at the beach? Other than try not to rub sand onto the lens? Will going from air conditioned rooms to the beach cause my camera to fog up and what can I do about it?

Thanks!

I would think the 70-200 would be a good choice. If you are planning not to shoot near dusk/dawn, the f/4 should be fine. The weight of the 2.8 isn't that bad, but I might just be used to it. You are correct that taking a cold camera into humid air can cause fog on the lens and viewfinder, so your best bet is to keep the camera in your bag for a while to let it warm up a little bit. Or, at the very least keep the lens cap on for a while.

timbop, thanks for the feedback, I appreciate it.

Justiss wrote in post #8299086
timbop, thanks for the feedback, I appreciate it.

You're welcome!