The dynamics of drawing strangers in an urban setting

Gentleman at Starbucks working
on his laptop.- pen& ink 6x9

   Although it is a little "different" to go sketching at a coffee shop it is even more tricky to casually sketch somebody sitting there doing their own thing. When I do this, I often get one of two vibes... either folks ignore me or they notice me and the tension thickens like dry ice. I've had folks get up and walk off when they realized I was drawing them and I always feel bad about that. The key is not to make it a point that I am observing them specifically when possible.
   Hating my own image being photographed, I can certainly sympathize with my victims. Photographers like Cartier-Bresson or Fellig  were fascinated with the candid. They ran into this predicament trying to catch images of people naturally in their own environment. Some even built devices with redirected lenses to where the photographer could point his camera in one direction yet redirect the "real lens" to take the image of someone to the side of the lens. If only we artists could be so fortunate to have independent vision on the side of our heads. Better yet try those kid's spy glasses that actuallyshow what is behind you.There is always working from reflections (large windows)...
As I cautiously "sneak a glance" I can't help but think,' If only my subjects knew that I am not so much watching them (with critical eye or judgement) but rather observing the abstract shapes, comparing values... and hoping they don't move before I get something worthy.
   Since I was less than 6 foot away from this stranger I'm thinking he knew what I was doing and just "went with it" in appreciation of the local artist sketching at the Starbucks. I was very appreciative because when reflecting the drawing as a whole, I thought it sure is a narrative that marks our culture in the typical urban scenery for this day and age.