It doesn't look like a lot, but there is a decent amount of equipment in my rollaboard photo case. The picture above is of the Pelican 1535 Air, a reasonably lighter weight Pelican case sized at the limit for domestic USA carry on. I've had no trouble rolling aboard a similar size case on European flights [though those carriers often also weigh your carry-on bags, which does occasionally cause a problem; it's difficult to carry quality camera equipment and a laptop/tablet and come in under 8kg]. Here is what is in the case:

1. Phase One XF w/ waist level finder
2. Phase One 40-80 zoom
3. Phase One 35mm
4. Phase One 150mm
5. Phase One !Q4.150 digital back
6. Hasselblad X1D
7. Hasselblad 21mm
8. Hasselblad 30mm
9. Voigtlander 15mm
10. MacBook Pro 13
11. High Capacity Batteries
12. Phase batteries
13. Hasselblad batteries
14. Swarovski binoculars

This collection weighs a little bit more than 8 kilos. ;-) And that doesn't include the two tripods and filter sets [a combination of Wine Country Camera and Formatt High-tech filter systems], chargers, and other paraphernalia that go into my checked bag with my clothing and backpack. When I get to my destination, I pull the foam dividers out of the Pelican and insert them into my backpack. That's the moment, and pretty much the only moment, when I wish I was packing lighter. Normally, I use Internal Carry Units or ICUs that are designed for Shimoda and F-Stop backpacks. But those ICUs don't work well in the Pelican; they work okay, but not well. Too much wasted space. So, using the original Pelican padded divider set as my ICU is a new experiment on this trip. I should know better than to try something new on an international trip. But seriously, what could go wrong?

Update: well, the answer is “not much.” For the most part, this has been a successful experiment. Transferring the padded divider Pelican compartment to the Shimoda 40L backpack works well. It’s a tight fit, and it uses up some of the upper space—where one might store filter sets and cleaning supplies—but not all of it. The dividers had to be reconfigured to accommodate a ready Phase w/40-80 zoom, because it doesn’t make much sense to carry the Phase in the field without the DB attached for immediate shooting. That had a domino effect and, while I am not loving the layout at 4:30am, it zips up and is carryable. Here’s how it looks:

Starting from the upper left and moving vaguely clockwise: the Phase 35mm; the Phase XF w/ 40-80 zoom, back, and WLF; Phase 150mm & High Tech Formatt 85mm filters system in pouch; Voigtlander 15mm & Hasselblad 30mm lenses; and Hasselblad w/ 21mm lens. 
But you know you’re doing something right when you use every piece of equipment more than once, and you don’t find yourself saying: “Damn, I wish I had the XYZ doohickey with me.”