The difference telescope f ratio makes. Cluster M37, image on the left is a 12.7cm f12 telescope; on the right a 20 cm f3.9 telescope. Same imager and exposure for both. https://octodon.social/media/xy1n8AAYCRsZ_s8qcjc https://octodon.social/media/oHfVLP6n_eplQ-D1j5M