HiLetgo 2PCS TSL2561 Luminosity Sensor Infrared Light Brightness Sensor Luminance Sensor

Perfect match for my imperfect project! No issues.

Works as expected

These work well and are very reasonably priced. One reviewer indicated that this implementation does not permit the selection of the I2C address, and they are correct to a point, in that the address line is not brought out to a pin like it is on the Adafruit version, but it is selectable using the small solder pads provided on the circuit board (circled in attached picture). As supplied the address is 0x39 ("TSL2651_ADDR_FLOAT" in the Adafruit Arduino library). If the center and "L" are bridged together the address is 0x29 ("TSL2651_ADDR_LOW" in the Adafruit Arduino library), and if the center and the "H" are bridged together the address is 0x49 ("TSL2651_ADDR_HIGH" in the Adafruit Arduino library). Using this method of addressing you can have up to three of these sensors on a single I2C bus without a multiplexer.

A pair of high-quality TSL2561 luminosity sensors. I tested 4 of these together I ordered from this vendor and they were all calibrated pretty consistently with each other, and relatively easy to use and compatible with 3rd party libraries (Adafruit's worked great if a line was commented out or overridden in initialization). The visible light reading capped out at 65k in direct sunlight through a window, but the IR portion maintained a smooth curve throughout the day.Main caveat is that while the TSL2561 is designed to support different addresses via i2c ADDR change pins, HiLetgo's version does not implement them. So if you planned to use this pair together on the same bus, you either need to find a way to configure another i2c bus (tricky on the Raspberry Pi) or buy a separate i2c multiplexer module which is what I ended up doing.