# Take exposures in a 4-point dither pattern 
# and then return to the starting point

printf ' ## four.pro exposure 1' 
go

tcs 'gdxy 0 -100' 
sleep 5
printf ' ## four.pro exposure 2' 
go 

tcs 'gdxy -100 0' 
sleep 5
printf ' ## four.pro exposure 3' 
go 

tcs 'gdxy 0 100' 
sleep 5
printf ' ## four.pro exposure 4' 
go 

tcs 'gdxy 100 0'  
printf ' ## four.pro finished'