A matter of perspective -- seeing is believing

On Tuesday evenings, this fall, I'm facilitating a drawing course. The participants draw better than they think they do, but, as we all do, they have questions and concerns about how they transform a three-dimensional object onto a two dimensional plane.  Last week, we dove into the topic of perspective and played with vanishing points, horizon lines, cubes and cylinders.  When translating theory into practice, however, more questions arose.

I decided to rummage through my many thousands of photos to see if I could find strong examples of one and two point perspective.  It was an interesting exercise for me, and fun, as well, as I got to play with my camera and on the computer at one point to create a composite image that would illustrate a concept.

Here is what I came up with and will show the class next Tuesday.  For those of you who know all about perspective, this may be very familiar to you.  For those of you who don't, there are many websites out there that explain perspective in detail. I'm providing you with solid examples of how the theory fits into "real-life" situations.

An endless corridor -- note the vanishing point at the very end!

So many lines in this image lead to the vanishing point.

Can you find the vanishing point in this image?

Sometimes the vanishing point is off the picture plane.

Two-point perspective; vanishing points are off the picture plane.

Vanishing points can be vertically located, as well (look up three-point perspective).

Here's where I got to play with the camera.  What happens to circles (viewed from the edge) when they are at, above and below the horizon line?  With a construction paper disk, a paint stick, a tripod, a camera and some merging of photos, I came up with this image.  Note:  the camera was stationary for the entire photo shoot.

Drawing in the ellipses helps to see the circle shapes better. Note that you are seeing the bottom of the top two circles and the top  of the bottom two circles.  If I do this again I'll mark the top with a big bright X or make it an entirely different colour!

One question arising in class was why I had drawn the curves differently at the top and bottom of the cylinder on my handout sheet.  This photo and the next three images illustrate the concept better than my words could explain.  Depending on where your glass/can/mug/cylinder sits in relation to the horizon line, you will get different curves depicting the top and bottom "circles" of your object.

Here the cylinder spans the horizon line (I could have drawn that in, but didn't) with almost equal parts above and below.  Note how the top and bottom curves of the cylinder are very similar in shape.

Here the top of the cylinder sits almost on the horizon line and the bottom sits well below.  Note how the top curve is almost a line, while the bottom curve is much more pronounced than in the previous image.

Here you can compare them side-by-side.