Hello, CIC people. I've been absent from the forum for a while but haven't stopped taking pics. It'll take me a while to catch up on posts but I hope everyone is well.
Late last month I was wandering around the marina at Port Alfred taking pictures at sunset. This was the last one I took. I wear multifocal glasses and I can't see the electronic information (metering/ISO etc) particularly well through the viewfinder, especially when the sun is behind me. Over the past year or so I've been using single-point AF, using the centre point (my Canon 100D has nine) to focus on the subject and then holding down the button and composing. There was something about the angle of this pic and the darker foreground that enabled me to notice that red blinker indicating the focus point had shifted: somehow I'd changed it to the AF point at 7 o'clock.
My initial thought was "Oh, hell, I've been shooting at f10, everything's going to be out." But then I went and looked at all the pics in Liveview, and they seemed fine, even when I zoomed in really close. And then when I pulled the pics up on the PC they were as sharp as anything I've ever shot! A pro-photographer friend explained why to me in some detail, along with some links, but the upshot was I learnt a valuable lesson by accident.
Comments and criticism welcome.