The impression of perspective can be elusive – essentially you’re visually convincing the viewer into seeing depth on a 2-dimensional surface! Here are a few factors that can play in your favour:
Overlapping forms: Foreground forms which partly obscure more distant forms will always indicate which is in front of the other, emphasizing a 3-dimensional aspect.
Size: Objects get proportionally smaller the further they are from the viewer. Populating similar objects at appropriate sizes at different distances leads the viewer to seeing depth. The mind will automatically read similar-shaped objects as the same size, therefore this will read well in perspective.
Conversely, beware of composing with smaller objects closer than larger ones of the same shape as this that can work against the illusion. For example, a small single-mast boat placed nearer than a larger one will detract . However if the larger boat is a three-master, there would be little problem – because the shapes are sufficiently different.
Object quality: How an object or passage is rendered will in itself have an impact on perspective:
- Value – High light-dark contrast will naturally read as closer, with faded or greyed out as more distant.
- Sharpness – Objects sink into the distance when they are diffused. A sharply-defined object will always appear closer than its more diffused neighbour.
- Detail – More detail within the object makes it appear closer than a simply blocked form.
- Texture – More highly textured objects and passages will appear closer.
I should note that all of this is fine and dandy, so long as it fits with the intent of the piece. A diffused, generally rendered foreground might help lead to a more distant focus. In this case, putting a lot of detail in the foreground would work against the intent of the painting.
Warm – cool colour contrasts: Warm colours advance and cool ones recede – again, a handy method of placing objects in space. A warm, orange- red object will appear closer than its identically-sized blue- green neighbour.
Position in the picture space: In landscapes, objects placed higher in the picture frame will appear further away.
Leading the eye: Whether with a path, fence or a series of trees, placement toward a distance focus will create the illusion of depth.
Linear perspective: I’ve left the most common principle to last – parallel lines recede into the distance to a vanishing point. This isn’t only useful with interiors, roads and cityscapes but with all manner of views where there is some “parallelness” to the scene, be it plowed fields, lines of trees etc.