Voltage, yes. Current, no not really. You can drive extremely low currents and still get photon emissions from LEDs. That said, it's highly non-linear, so you b

Voltage, yes. Current, no not really. You can drive extremely low currents and still get photon emissions from LEDs. That said, it's highly non-linear, so you basically need to assign set points. Doubling the current won't double the lumen output.