choosing a bleed resistor

[A_Camera]

Or use a NTC thermistor.

BTW, that design - the resistor wattage values are wrong - if, as claimed, it's intended to limit the current to 5A then the resistors should be rated at 250W (P=I^2 x R). I'd also caution that C1 is specified at the limits of its operation - failure of that would result in the explosive failure of C2 C2 and likely destruction of R1 and RE1.

Treat with care.

Oh, you dissipate about 6W in that capacitor and relay.

True. I haven't build that circuit, so no warranty about it's functionality.

And A-Camera, electric shock isn't the only hazard of a charged capacitor. The biggest hazard at this potential are burns and physical injury resulting from a spontaneous reaction to a sudden discharge. You mention batteries - of course you don't use a bleed resistor on batteries - that's a divisive argument. But the first instruction in any vehicle maintenance manual is to remove the -V lead before any work. Why?

...because of explosion risk...? Lead batteries can LITERALLY explode in your face and a car battery explosion is extremely dangerous because of the acid inside. Apart from the actual battery explosion, the heat it generates if short circuited is more than enough to set everything on fire. If none of that happens, the sparks which are/can be created are so large and powerful so the fuel can be set on fire, and if there is the exact right mixture of fuel (oil and/or petrol/diesel fumes) and air then the whole car will be blown to pieces, taking you with it... Removing the car battery is indeed important, especially after an accident, but maybe not any work. I don't remove the battery for work I do on my cars, like "normal" maintenance, filling of fluids, changing of tires and so on. Everything else is left to the experts, and they aren't always removing the battery for the normal service.

You can't compare car batteries with capacitors or smaller batteries. Also, cars contain other circuitry as well, not just rectifier and capacitor, like a simple PSU. ...but I mentioned that there is a slight risk for surface skin burns.

The argument about the batteries is still valid. A simple power tool battery, or even a lithium camera battery contains more charge than a capacitor and NOBODY of sane mind would think about bleeding resistor.

After a few accidents I ALWAYS discharge the main capacitor in camera flashes before I open one. A tiny flash using 3V battery power makes your heart beat a few extra beats if you are not careful when you open a flash...