Low cost Analog Light Sensors For Your Light Sensing Needs

From Adafruit

1. PT550

This has a illumination range of 1 Lux to 6000 Lux with a response time of 15us. It translucent reflective body looks great like a typical LED. This type of photo-resistor is made of environment-friendly materials(no Cadmium and Lead) compared with the traditional CDS photoresistor.

From DFRobot

2. TEMT6000

Temt6000 is supposed to be adapted to the sensitivity of the human eye with an illumination range of 1–5000 lux, but it sometimes performs sub-par in low light conditions. Using Temt6000 is perfect if you want to sense ambient brightness with a little more precision without adding complexity to your project.

From Sparkfun

3. GAIA12S202

This GA1A12S202 have a true log-lin relationship with light levels. Most light sensors have a linear relationship with light levels, which means that they’re not very sensitive to changes in darkened areas and ‘max’ out very easily when there’s a lot of light.This sensor is logarithmic over a large dynamic range of 3 to 55,000 Lux, so it has a lot of sensitivity at low light levels but is also nearly impossible to “max out” so you can use it indoors or outdoors without changing code or calibration.

This breakout board from Adafruit has a 68k ohm resistor from out to ground and a decoupling capacitor 0.01 microFarads to reduce the effect of noise and stabilize the powerline .

From Adafruit

4. CDs PDVP8001

A Cadmium-Sulfide cell are light dependent resistors which are small, inexpensive, low power, easy to use and don’t wear out. They are basically resistors that changes its resistive value depending on how much light is shining on its squiggly face. They’re easy to get in many specification but are very inaccurate, each photocell will act a little differently than the other even if they are from the same batch, and the variation can be really large, 50% or higher. For this reason they shouldn’t be used to determine precise levels in lux, you can only determine basic light changes like “it is light or dark”.

Photocells, particularly the common CdS cells that you’re likely to find, are not sensitive to all light. In particular they tend to be sensitive to light between 700nm (red) and 500nm (green) light. Basically, blue light wont be nearly as effective at triggering the sensor as green/yellow light!

From Adafruit