shell script to generate pictures for a timelapse with RaspberryPi camera module using raspistill

tl-pi.sh

#!/bin/bash

echo "how many pictures you want to take?"
read hmany
echo "at which interval"
read interval

counter=1

while [ $counter -le $hmany ]
    do counter=$(($counter+1))
    pictname=`date +%s`
    raspistill -o tl-$pictname.jpg -q 100 -v -ex off -awb off -mm average -t 100 
    sleep $interval
done

sample video:
http://youtu.be/49B9zRhSGrk