set terminal postscript eps color enhanced font "Helvetica,20pt" size 12cm,9cm 

# common settings
# set log y 10
# set format y "10^{%T}"
set format x "%2g"
set format y "%0.0f"
set tics scale 2
set tics nomirror
set xtics 1
# set ytics 1
set xrange [566.5:572.5]
set yrange [0:2500000]

set xlabel "Wavelength {/Symbol l} [nm]"
set ylabel "Transmission [counts per second]"

set output "filter.eps"
plot 'filter.txt' using 1:2 w p ls 1 lc 1 ti "arc", "" using 1:3 w p ti "bandpass", "" using 1:4 w p ti "etalons"