Better Vision in the Shop


Proper lighting and vision aids can make a woodworking world of difference.
By Rob Porcaro
Pages: 63-65

From the February 2010 issue #181
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Woodworking is a visual art. The capabilities of our eyes and visual system, as well as the quality of the conditions in which we use them, are essential to good woodworking. Basic knowledge of visual function in the shop and the aids used to enhance it can improve a woodworker’s skill. It is also helpful to know a few visual tricks to achieve even better visual performance than seems usually possible.

Let’s first look at the power of this marvelous tool – the visual system. If you are fortunate enough to have 20/20 vision in either eye, with or without corrective lenses, you are able to distinguish, at a viewing distance of 14″, in proper conditions, critical detail in your work of .004″ (four thousandths of an inch). That means if you are cutting dovetails with your eyes 14″ away from the wood, you can see detail equal to the thickness of a sheet of paper.

Even more powerful is “vernier acuity” with which you can discern a displacement of less than .001″ of two fine lines, such as registration marks on a pair of boards. When using this “super” visual ability to align your work, your eyes equal or exceed the accuracy of the finest calipers likely to be in your shop.

Further, the eye can readily detect a gap of light of a mere .0005″ (half a thou) under a straightedge placed on the sole of a plane held up to diffuse light. That’s probably more accuracy than you need. Turn out all the lights in your shop except one narrow beam aimed across the room to see previously invisible, minute dust particles in the air hovering long after a sanding session and destined for your lungs.


From the February 2010 issue #181
Buy this issue now