I have never been good at drawing to say the truth and that's why I can't give a comprehensible question. Now I am into choosing a home theatre projector and the only thing I can think of is Epson EX7220. It is a projector I really like and I am reading reviews already
Drawing from observation is when you have a model in front of you, it may be real, let's say a landscape or even a photo, a picture from a book, etc. Drawing from memory is when you keep in mind something you saw in the past, and then you try to reproduce it, to draw what you have kept in your memory , usually making a personal interpretation of it.