People Unaware

I've been taking unaware photos with a long lens for a long time:

This was at Amberley Working Museum, near Arundel.  It's been processed using the Threshold filter in Photoshop.  I think the camera was just resting on the outdoor cafe table, which is a nice firm base.
With a long lens it's absolutely clear what you're shooting, if anyone notices, but folk often don't.  Some kind of hide or shade is handy.  A clean cafe or shop window can be shot through without alerting the target.

It helps if the subject is distracted.  Photographers are so easy!

Last night I tried using wide angle: 18 mm on a 1.6 factor sensor = 29 mm in full frame.
I learned a bit:
Focussing has to be planned: focus on something else about the right distance; set a single extreme right or left focus point (hitherto, my camera was invariably set to a single central point, and I'm used to focussing first, then framing before I shoot); or focus manually, which takes time.
You have to be close, so the subject is usually aware you're taking a photograph.
Even close, you're only using a fraction of the sensor, so unless you have a lot of megapixcels, the definition can be poor.
Lens performance at the edge of a wide angle can be reduced and the image may be distorted.

Here are some initial results:

I'd only f4.5 to play with, so there is too much depth of field.  A faster prime lens would be better.    I had to blur a couple of faces in the centre to reduce their prominence.  The cropped image suffers from poor definition, partly because in these available light indoor shots I was using ISO1600:

This lady is aware and suspects her photograph may be being taken: