As TheRook points out, it need not be a bag designed for cameras/lenses. I have two travel cases that I use for my photo gear when a good deal of walking will be involved. One is a carry-on in which I've made compartments within it using closed foam inserts. It is fairly compact -- about 12" x 12" x 8" deep, and has two wheels and a telescoping handle to make rolling it along easy. The other is a mid-sized soft-sided piece of luggage, too big for a carry on. This one is about 24" x 16" x 10" and has four wheels on the bottom and an extending handle. I like the four wheels. I use this one for my bigger stuff. I have a couple of large zooms and telephotos that are too big for my carry-on. It also works well when I want to transport my Pentax 67 system and other cameras with a few of their lenses. I've used closed foam to create compartments with this soft-sided piece of luggage as well. By repurposing luggage in this manner -- luggage that can often be found at thrift stores for chump change -- one can save a huge amount versus buying large camera bags or backpacks or whatever.