Do yo have the specs for the LED?
Something is limiting the current. A 10W LED actually running at 10W would probably "blind" the camera. Power is calculated as Voltage x Current so a 10W / 10V LED would be running at about 1 Amp.
I'd guess you are powering the step-up converter from an I/O pin. If so, that's wrong! The I/O pins are rated for 40mA maximum so if you are powering the board that way you are overloading the I/O pin and if you measure the voltage you'll probably find the 5V is not holding-up, and that's what's (improperly) limiting the current. (You'd have to modify your code to hold the LED on while you measure voltage.)
The Arduino I/O pin should drive a MOSFET, or relay, etc., to control power to the LED, with the power coming from somewhere else.
High-power LEDs are normally driven with a special constant-current power supply. As with small LEDs and a resistor, with the proper current the voltage "falls into place". You can use a regular constant-voltage power supply and a power resistor, but the resistor needs to dissipate (waste) about the same amount of power as the LED (depending on the design details) so this is a poor design and it's rarely done. There are dimmable/controllable constant-current LED power supplies/drivers. (Technically, the dimmable supplies are controlled current.)