I discovered something interesting about backup bodies the other week, on a shoot where my D300 was my principal camera on the grounds that I needed something smallish, lightish and above all as unobtrusive as possible. Look, I love my D3, but subtle it ain't. Stealth was the name of the game (all will be revealed at a later date, but trust me - it's not as exciting as it sounds) and the D300 was the weapon of choice.
Which left me with a bit of a dilemma.
See, it's like this. Pack the D3 and a fistful of lenses, and it makes sense to shove the smaller-sensored D300 in as a backup. All you need to do is make sure you've got a reasonable wide option, and you're good to go.
But approach it from the other end, and the whole backup thing starts unravelling. With my D300 and a small selection of lenses including my DX-only 50-150mm making up my main kit, the D3 was starting to look a bit silly as a backup. Aside from the fact that it was taking up almost as much space as the entire D300 kit, I only had one lens that would work with it... and no long lens options.
The solution was impractically ludicrous. Since the shoot was in London and I'd be within relatively easy reach of my car for most of the day, I opted to take not just the D3, but a couple of spare lenses to go with it. All packed in a separate bag... locked in the boot of my car (armed with a Thatcham cat 1 alarm... so at least if someone made off with my gear they'd take away an earache too)... parked at great expense in a secure underground carpark.
Daft, I know. But it's brought home the stark reality of running twin formats in parallel: some things just got more complicated (/heavier/bulkier).
Solutions on a nice compact, please, carefully wrapped in bubblewrap and left by the back door under the metal bucket...