While viewing a lot of photos where the author is looking for C&C, sometimes run across the odd comment about something being under-exposed. Either my monitor is much brighter than everyone elses or I have a really poor eye on seeing where the under-exposed areas exist. In some night shots, it is definitely plain enough. Maybe we should have a rating scale of how badly exposed a photograph is in their opinion for an average consensus? Scale of 1 to 10 maybe? Here is an example I know is poorly exposed for everyone to beat up on the aforementioned scale of reference.