The image of Pleiades Open Cluster (Messier 45) is a stack of 32 frames taken with Pentax K-1, Pentax SMC F* 300mm lens and Astrotracer.
Actually it is quite difficult to calibrate Astrotracer with 300mm lens. Only after several tries I was able to get 30 sec exposures. The stars are not round, but it is an effect of few worse frames which I did not exclude from stack. I think it is not bad, taking into account it was done without equatorial motorized mount, just regular tripod.
#!/bin/bash
# Written by Piotr Dlugosz
# License GPL
#set -x # uncomment to debug
# ***** SETTINGS *****
# Base directory for the photos
BASE=/home/share/ASTRO
# Serial port for BULB cable
SPORT=/dev/ttyUSB0
# Gphoto2 settings
OG="--quiet --port usb: --set-config shutterspeed=Bulb --set-config imageformat=RAW --set-config focusmode=3"
# Photo parameters (these params can be given on the command line)
OP="name=test frames=1 exptime=10 iso=400"
# ***** END SETTINGS *****
# ***** HOOK PART *****
if [ "$ACTION" = "download" ]; then
echo "DOWNLOAD"
geeqie -t -r "$ARGUMENT" #>/dev/null 2>&1
fi
[ "$ACTION" ] && exit 0
# ***** END HOOK *****
# ***** START *****
echo "*** FOTO AUTOMAT ***"
[ -d "$BASE" ] || { echo "$BASE does not exist!"; exit 1; }
# Ask for parameters and set the script variables
eval $OP # set the defaults first
if [ "$1" ]; then
eval $@ # if command line is not empty take params from command line
else
read -ei "$OP" -p "Enter the photo parameters: " ANSWER # otherwise ask
eval $ANSWER
fi
# Prepare environment
ABSPATH=`cd ${0%/*} && echo $PWD/${0##*/}`
DATE=`date -d "-6 hours" +"%y%m%d"`
NAME="${name}_${DATE}_$$"
FOLDER="$BASE/$name/$DATE"
[ -d "$FOLDER" ] || mkdir -p "$FOLDER"
cd "$FOLDER" || { echo "$FOLDER does not exits!"; exit 1; }
echo "** Folder: $FOLDER, session number: $$"
echo "** Params: exptime=$exptime frames=$frames iso=$iso"
((count=frames-1))
export count
# Start gphoto in tethered mode and set the parameters
gphoto2 $OG --set-config iso=$iso --filename "${NAME}-%03n.cr2" --hook-script "$ABSPATH" --wait-event-and-download >~/gphoto.log 2>&1 &
# Loop to make photos
for a in `seq 0 $count`; do
echo -n "* Frame: $a/$count "
sleep $exptime >$SPORT
echo "finished."
sleep 0.5
done
# Wait till the last photo is saved before exiting
LASTPHOTO="${NAME}-`printf '%03d' $count`.cr2"
while [ ! -s "$LASTPHOTO" ]; do
sleep 1
done
echo "Killing gphoto"
pkill gphoto2