Both work wire types fine. I have gone to a solid wire for the purpose of positioning my wires a certain way inside the case. The braided wire tends to flex back a bit after you have positioned it. If we were having to move the components around more often, then the flexibility of the braided wire would be best. Braided would greatly reduced the chance of breaking a wire free from it's solder connection. So it is really up to which one you feel more comfortable using.
I have a wad of that old telephone wire out in my garage, but it's getting scarce now-a-days. Some of the younger folks probably never seen the stuff. Sure it will break if you bend in to many times, but it fits in a tight place like inside a camera. The trade-off with stranded wire is that you can't hold your solder in one hand while feeding fresh solder into the joint. So, it boils down to cold solder joints with stranded, or broken wires with solid. But of course, if you can get your wife to hold the stranded wire while you solder it correctly, then you get the best of both worlds. (mine wont)
You can use the stranded wire with hot glue to hold it to the sides of your cam. That way it doesn't flop about or lose position. I even used hot glue to hold the wires together because I did not have a plastic wire tie handy.
there is no reason for a third hand to solder up a camera. If you tin your stranded wire and tin the point where you are soldering the wire to, then lay the wire next to that point and flow both solders together it will be a good solder connection. You can also hold the solder tube in your mouth and feed it into the solder job that way.
One of my biggest headaches at work is older solid wire and solid center conductor antenna coax. It will break eventually, usually at the worst time too.
Hi spectr - Okay, I'll try one with stranded wire stuck to the board. This is a true story, and remember that this wire debate has been going on since WWII. Back around 1980 I put together a teletype terminal with all the switches wired with the old solid telephone wire. I looped the stuff neatly on the back side of the 7 switch, and it looked like a master piece. A few years later the heat & cold out in the garage caused one of the little wire loops to snap. It had to happen on the night that I was the duty station relaying traffic from the fleet to their families. Seems like equipment failure always happens at the worst time.