Not only photographers, but also cloudspotters look closely at things and notice details. I once worked as a meteorologist for a boss who had a degree in Physics, but who had never looked at clouds long enough to notice that they change shape. He didn't know they did that until I pointed out some changes to him one day over a period of 10 minutes. He was very surprised to see the difference!
By the way, lads, if GWW can cast her mind back to her Latin study days, the words for layers are Stratum (singular) and Strata (plural) NOT Stratas