The TSL2561 luminosity sensor is an advanced digital light sensor, ideal for use in a wide range of light situations. Compared to low cost CdS cells, this sensor is more precise, allowing for exact lux calculations and can be configured for different gain/timing ranges to detect light ranges from up to 0.1 - 40,000 lux on the fly. Contains both infrared and full spectrum diodes! Most sensors can only detect one or the other, which does not accurately represent what human eyes see (since we cannot perceive the IR light that is detected by most photo diodes).

• I2C-controlled
• Works with both Raspberry Pi and Arduino
• Low current draw (0.5mA when sensing, 15uA when idle)
• Address select pins (up to 3 of these on a single I2C bus)
• Separately measure infra-red, full-spectrum or human-visible light
• Built in ADC means you can use this with any microcontroller (even if it doesn't have analog inputs)
• Fully tested and assembled breakout board
• All headers included (to solder yourself)

A little light soldering will be required to assemble and customize the board by attaching the desired headers but it is a 15 minute task that even a beginner can do. Check out Adafruit's great !