Revised detector circuit for LED fade out only (emitter circuit from page one remains the same):
Q1 - S9014 NPN transistor
Q2 - Phototransistor (IR Detector from original circuit)
D1-D4 - LEDs with 120 degree illumination angle
Everything else should be in the picture.
When the detector is blocked, the transistor activates, illuminating the the LEDs and charging C1. When detector is unblocked, transistor shuts off and Cl discharges through R2. Fade out time can be adjusted by changing the value of R2.
R3 needs to be calculated for the LEDs you use.
Video shows circuit exactly as shown in the schematic.
https://m.youtube.com/watch?v=2GGZSZFYRH8
