Double Exposures are Easy!

The low speeds are on the front mounted shutter dial, the high speeds on the top mounted shutter dial. The top mounted dial ROTATES during exposure. To set the shutter speed, advance the film FIRST. Then raise the top shutter speed dial and rotate it to match up with the desired speed. If you match it to the lowest number, usually 1-20 or thereabouts, you enable the slow speed dial. Then rotate that to your desired speed. Warning: you can get uneven exposures by resting your finger on the top shutter speed dial during exposure. Yet, if you want double exposures, ALL you have to do is turn the high speed dial in the opposite direction until it catches. That re-cocks the shutter, and you can take another shot. Repeat as many times as you want.

J'ai lu sur Cameraquest qu'on pouvait facilement faire une double expo avec les Leica à vis en re-armant de declencheur en tournant le selecteur de vitesses:

Or, sur mon II (ou I? Comment dois-je l'appeler?) tourner le selecteur de vitesses ne réarme pas le déclencheur.

Comment faire?

Je déconseille cependant cette manoeuvre car le système est assez fragile