LED Dimming: PWM vs Current

In this video, I demonstrate two different ways to dim an LED, along with electrical analysis of the circuits using a multimeter and an oscilloscope.
Skip to 9:39 for the bit about Arduino PWM.
3d printed lithophanes: www.createthis....
Here is the Arduino gist, as promised in the video: gist.github.co...
These are the products I use or mention in the video:
LED light strip (not the one in the video, but similar and less expensive - this is what I would buy today, personally): [amazon affiliate] amzn.to/1IOkHBN
Arduino Uno Ultimate Starter Kit -- Includes 72 page Instruction Book: [amazon affiliate] amzn.to/1N7pVyB
SainSmart UNO, ATmega328P USB CABLE Included for Arduino: [amazon affiliate] amzn.to/1IOkiz6
Fluke 87-V Digital Multimeter: [amazon affiliate] amzn.to/1JGSwIG
Extech EX430 True RMS Autoranging Multimeter with K Type, Capacitance, Frequency, and Duty Cycle: [amazon affiliate] amzn.to/1N7qb0D
RIGOL DS2072A: [amazon affiliate] amzn.to/1N7qf0p
Rigol DS1054Z: [amazon affiliate] amzn.to/1IOkBtR