Quoted By:
I think a lot of people overestimate how well they can visualise things. If you could really visualise things fully in complete realistic detail then you would draw entirely from memory and never bother to use references.
Your mind's eye probably functions similarly to how your actual eyes do, that is you don't see the entire object in full detail all at once, but instead your fovea sweeps over the object picking out only small sections of detail at a time, largely ignoring most of the object and just assuming it will look as expected. But where with a physical object the details are persistent so you can easily refer back to them, the mental object's details are only persistent in so far as you can hold them in your memory outside of the section your mental foveal is currently focusing on. It's pretty hard to do this with an entire object unless you're intimately familiar with it to an extreme degree. For example, most people have seen the human body multiple times a day every day for their whole lives, but if you ask them to draw it, it will be their knowledge of anatomy holding them back just as much as their drawing skills. Obviously giving them a reference to copy from would instantly increase the accuracy of their drawing, yet they would still probably claim to be able to visualise a person perfectly. Really what they're seeing in their head is more of a vague impression of a body with few key details brought into mental focus, and the rest is just assumed, but it still feels complete because this is how your actual visual system works as well.
