Education Forum

Perspective - Part 2

By Margaret Saul

Originally appeared in The Botanical Artist – Volume 14, Issue 2

 

Master the Ellipse and the Midline and drawing flowers will become a breeze!    

An appreciation of perspective drawing basics helps students visualize the third dimension. An essential part of learning to draw is mastering the perspective view of a circle, which relates closely to the geometric ellipse. Drawing circles in perspective allows students to observe how changing the viewing height (eyelevel) and the angle of the plane (surface on which the subject “sits”), effects the degree of distortion of the natural shape.  Drawing ellipses also provides an opportunity to introduce the concept of the midline that greatly aids in the drawing of geometric forms that underlie many floral elements - inflorescences, (cut) stems and other plant parts that are more or less symmetrically structured.

Awareness of a midline or central axis visualized through a symmetrically structured flower ensures that all elements – the ellipse formed by the corolla or corolla tube, angles of individual petals etc. are correctly aligned. The daffodil presents challenges, in particular in a three-quarter view. Drawing of the corona must appear convincingly centered over the corolla and insertion point of the stalk. This involves a mid line on which three parallel ellipses are centered – one that roughly contains the outer diameter of the corolla (arrangement of tepals) and the two ellipses of the cylinder formed by the corona. It is vital to include the entire outline of an ellipse in the initial sketch to achieve a convincing curve on the visible side of a round element e.g. the corona, and to appreciate the hidden position of the insertion point of the stalk near the base of the corona.

A geometric ellipse has a major axis (longest dimension) and centered across it and at right angles to it, a minor axis (shortest dimension). These two axes divide the ellipse it into four equal parts. In reality, due to foreshortening, a circle in perspective is not entirely symmetrical because you usually see slightly more of the foremost half due to foreshortening. The center of a flower will actually appear as set slightly back from the center.  However, learning how to draw a perfect ellipse is a useful place to start.

Instruction with practical demonstration where necessary:

Have students use a loose page that can be freely moved and practice  sketching circles, quickly and lightly with only the end joint of their little  finger gliding over the page to steady  their drawing. Then demonstrate how to draw ellipses within set dimensions. 1. Set the dimensions of the axes (freehand). 2. With light pencil pressure start the outline by drawing the curved edge at the end points of each axis. Stress that ellipses do not have pointed ends. 3. Lightly complete the outline. Check that the quarters of the ellipse appear reasonably equal. 4. Important – check symmetry by turning the page so the major axis is vertical and adjust the outline where necessary.

Teaching Aid: Cut out a three inch square of cardboard, rule diagonals from each corner to establish the center of the square. Using a compass, draw two circles: one circle filling the square and a smaller concentric circle approximately 1” in diameter. Intersect the center of the circles with two lines, each one parallel to a side of the square, to see the circle divided into equal quarters. Have students hold the square so this plane is horizontal and positioned 90 degrees out from the back of their (vertical) Plexiglas picture plane, slightly below eyelevel, to exhibit the circle as an obvious ellipse. Observe the shape of the square (now a rectangle) and note how its receding edges lead to vanishing point(s) on the horizon. Hold the square at various heights, including at the horizon line (eyelevel) so only the edge of the card is visible on the picture plane.

  • The tumbling circle: This teaching aid (3” square on cardboard with crossing lines on the diagonal and vertical and horizontal lines all crossing at the center) easily demonstrates the distinctive changes in a circle as the viewpoint changes when the square tips back away from the viewer. Circles become ellipses, squares turn to rectangles due to the effects of foreshortening.