Originally Posted by
Donald
That is the crux of it. The answer to the question flows from answering this question.
If it's a family holiday/vacation, then one or two lenses that will cover the sort of stuff that you can realistically be expecting to shoot. In my own case, I'm going to visit family in Malaysia in January. It will be one body and a couple of lenses. But in September I'm going to Yosemite for 4 weeks specifically for photography. For that, everything is coming - two bodies, 4 lenses, all the filters, tripod, etc etc. The works. Not sure how I get it all in a carry-on case yet, but I've got a few months to work on that one.