What do you do when the weather sucks? Right, you test your new tele extender from the safety of your opened window! I was randomly locking onto people passing by, small texts on containers and license plates of further away cars to test the overall auto focus performance and picture quality in the center and especially in the corners. Turns out the quality is better than expected :).
The picture on the right has been taken with the 7D plus 35L at f8, giving you a little less than the perceivable human field of view. The security camera is next to the metro station (red circles), on top of a mast about 15m high and about 35m away from the DSLR (sohphisticated guesses due to ∞).
Let’s do the math for this setup real quick: 200mm lens plus 1.4x extender plus 7D (1.6x crop) equals about a 448mm field of view. Approximately because there are minor variations in the focal length of the lens(es), even if it is labeled as 200mm. You can also notice how the background is less blown out due to the increased aperture of 1 stop, moving it up to f4 from f2.8.
Thanks to Teo for pointing out what I did not express: the camera is towering over all the windows (hence the title), but is ultimately being overwhelmed by the amount it tries to control. SPOILER. To be fair though it is pointed at something different :).