I always thought aphantasia was a thing you either had entirely, or not. I thought it ought to be a scale but I never heard anyone say it was until today. I'm a 4.
There was an interesting comment when this image was posted to reddit 6 years ago.
quadraspididilis
I'd call myself a 3, but I don't find the twitter illustration very accurate. The apple isn't low resolution like in the drawing, but it is insubstantial. Like hold your hand a couple of inches in front of one eye and then try to read this; you can still see your hand, but it's mostly see-through because your brain is mostly ignoring that eye. My experience of picturing the apple is like that, but the apple is in focus. Also, I have a hard time holding the image for more than a second.
This is me, but with a very faint ghost hand. I also can't hold it still. Sometimes when I wake up in the middle of the night I become a 5. Sometimes if I have an edible I can hold on to images longer.
I feel like i understand so much more now about myself and others. This is why I struggle to make art that isn't just copying something. This is why I struggle with role-playing games.