I accidentially got two SF313. They are phototransistors, here is a datasheet: http://pdf1.alldatasheet.com/datasheet-pdf/view/45649/SIEMENS/SFH313-2.html
As far as I understand it if I apply +5V to it's collector-emmiter, the current running throw it will be proportional to the ammount of light (that's why it's have "High linearity" feature). Here is a drawing from datasheet:
The dark current and photocurrent as far as I understand is max in the dark and max current with light respectively:
So my plan is to connect the following way:
+5V -> SFH Collector -> SFH Emmiter -> Some resistor to "convert" current to voltage -> (point of ADC connection) -> GND
Is this a right way to convert current changes to voltage changes? How to choose a resistor?