Rembrandt, Portrait of Aechje Claesdr (detail).
The fundamental element of Sight-Size is accurate comparison. Without it, your guesses are akin to guesses in arithmetic. You might be correct, but you’re far more likely to be wrong because there is only one correct answer. As with some answers in arithmetic there are many ways to check your work when in Sight-Size. One common way is using a plumb line. But what happens when you can no longer clearly see the line? What happens to Sight-Size with older eyes?
If you’re fortunate enough to have studied both while still being young and with someone who instilled in you the importance of the guess and check, you’ll have very little difficulty adjusting to your aging eyes.
One Challenge of Older Eyes
If you’re in your 40’s and/or learned to draw by simply copying your measurements, you are in for a challenge as you age.
Because mechanically measuring (whether in Sight-Size or not) requires the ability to focus both near and far almost simultaneously. This ability diminishes with age. But don’t worry, it’s completely normal and is called presbyopia.
Sometime in your 40’s you’ll begin to notice that when you focus on your plumb line your setup will be blurry.
All is Not Lost
All is not lost, however. In fact, you may have some advantages over your younger self.
Mentioned above is that Sight-Size should be taught using the guess and check. In other words, first make a guess by eye alone and only after your guess would you rely some form a mechanical measurement to check your guess.
Do that enough times and you’ll eventually realize that your instrument of choice, be it a plumb line, stick, or your drawing implement, introduces small errors of its own. In the end, it’s simply a guide to the correct direction and so you’re ultimately forced to rely on your naked eye anyway.
Yes, instruments do help. But they’re not the only way.
When you can clearly see your setup, your plumb line will be out of focus.
As shown in this photograph, the plumb line is not even visible!
Comparative Measuring Problems Too
When in Sight-Size your subject and your artwork are commonly seen at a distance from your vantage point – sometimes a heroic distance. This means that focusing is the same regardless of which item your focus is on.
Additionally, when you walk up to your artwork you’ll have a singular focus there as well, even if you need cheaters (reading glasses).
But if your drawing is in your lap, or otherwise nearby, and your subject is out in the distance, you’ll need to alternate between cheaters to see your drawing and something different to see your subject. Measuring a common unit (like the size of the model’s head) and scaling that up or down to the drawing becomes a frustrating exercise in alternating lenses.
And, as anyone who wears glasses knows, unless you’re looking through a specific area of the lens, they can distort as much as they sharpen.
Besides presbyopia, other issues can affect your ability to draw and paint what you see as you age. Chief among them are dimmed values and yellow-tinted colors. More noticeable is that your visual acuity (sharpness) may not be completely corrected with glasses or contacts at any distance.
As long as they are not in the extreme, none of those issues may be that much of a hindrance.
If your eyes are dim they will be equally dim when viewing both your artwork and your subject. You’ll therefore have as good a chance at accurately representing the correct value relationships as does a 20 year old.
The same issue relates to tinted sight.
A similar argument also applies to edges. More important than a singularly accurate edge is how that edge relates to all the other edges in the scene. If you can draw or paint the correct relationships, the viewer will see what you did. Yes, that may well be a bit too soft. Then again, in this age of photography we seem to forget that in nature a sharp edge seen up close is not a sharp edge when seen from a distance.
Older eyes do not have to limit Sight-Size. They may even force you to look more carefully.