comet observations during night 16/17 july 2018

between periods of clear periods and cloudy weather i could catch 4 comets for follow-up:  21P, C/2017 M4C/2017 S3 and C/2018 C2 . quality isn’t very well due cirrus clouds and high humidity and high light-pollution. area around comet C/2017 S3 was about SQM of 16.5 !