20W halogen derated to 10W (so it's very yellow, and not very efficient). At 20W it blew out the photo to the point where I didn't think it was a useful comparison. Note that the difference in battery size between supplying 50mA and 2A is significant (300g vs 2.5kg, with the 2.5kg battery only good for 2-3 hours rather than 40 hours from the 300g pack).