General art questions

[Auro-Cyanide]

The way itself is correct. I think the name horizontal line confused you.

They are vanishing lines. The horizontal line is one of a vanishing line. Only if planes are parallel to the earth surface, vanishing lines these planes make are equal to the horizontal line.

A vanishing line is the sum of the vanishing points of any lines on a plane. (Sorry, I can't explain it well in English)

(To be precise, that object has 3 vanishing lines. what you draw as upper horizon line isn't vanishing line, but explain it is too confusing)

You might have a point. Generally I've seen them refered to as the horizon lines regardless of whether the horzon is there or not. If you look up at the sky you can't see the horizon, but the vanishing points still exist. Vanishing line kind of makes more sense since it's a collection of all possible vanishing points on a particualr plane. The horizon line is just the vanishing line that is horizontal and perpendicualr to the vertical. That means that there must be more vanishing lines for planes that exist at angles from the horizontal plane.

Huh. Suddenly that makes a lot more sense.

[junna]

That's a good checklist. Particular the focal length of the "camera lens" you're employing. Film artists that do a lot of plate work can start to recognize the focal length of the lens used on sight. It can really add dramatic impact to an image when used properly.

Photographer's consider a 50mm lens to be the closest to the human eye, but even 50mm photos don't truly show how we see the world. Artists fake more realistic perspective with 3-point perspective, but to truly replicate the real world in drawing, you'd need to use 5-6 point or more curvilinear perspective. That'll wreck your day sketching it out.

55mm, wide- to ultra-wide-angle lenses are considered as "the closest human eye" lense.

anyway, photographers (and painters) generally compose pictures according to 'rule of thirds'
where a 'strong' picture is composed with the "most important elements at the intersections of imaginary lines that break the frame up into thirds (two horizontal and two vertical lines that form a nine part grid)." => http://prophotoguru.com/using-the-rule-of-thirds/

The rule of thirds is in quite a lot of opinion the laymans/lazy man's way of composing a picture using the 'Golden rectangle+ratio'
=>eg: http://jakegarn.com/the-rule-of-thirds/

but then...it's not a hard an fast rule...yet in general, I see pictures composed using the rule of thirds and golden rectangle generally has a bigger impact/feel to it...
err, dunno how this could relate to the art here. CGs maybe?