@variablepulserate The classic advice is the denominator of the shutter speed should be no lower than the focal length in mm (for a 35mm camera), so with a 50mm lens you shouldn't go slower than 1/50.
Stabilisation is apparently able to add 5–6 stops to that now, which suggests you could handhold the same focal length to 1/2 or even 1 second. I haven't tried it for myself though.