Apropos of nothing... no, let's tie this in with the recent launch of the Nikon 1 system. (Cough). Crop factors. About ten years ago. It was. About. A long time ago. Many years. Several. It was all the rage, a few years ago, to write blog posts about cropping factors, and this one's mine. A bit late to the party, but that's okay. I don't like parties. I also don't like writing introductions, I'm not warmed up yet. I take a lot of warming up. Cue picture, which you can click on, although you might prefer to right-click and select "view image", because it's larger than Blogger's preview:
The original was taken with a Canon 5D MkII, using a Nikon-mount Samyang 14mm f/2.8. As you can see, the corners are rubbish on a full-frame camera (check out the hotel in the top right), but splendid on all the crop formats, which makes me wonder why Samyang don't release a dedicated APS-C version of the lens with a smaller front element and a filter thread.
When I took the image I was standing half-way up the Sousse Residence in Sousse, Tunisia, in March 2011, frazzled after spending the morning exploring El Djem. The place seems to have closed since then (the website still exists, but their listings are gone from Tripadvisor and so forth). Nice place; cheap; big rooms; lots of cracked paint, not too sure about the wiring; cheap; just around the corner from the train station; cheap. Here are some more shots taken just around the corner:
With a Zeiss 50mm f/1.4. But, anyway, back to the crop factor image thing. You'll notice that it's split into segments. That's because it's too large for the Blogger platform. I've put a copy of the single, unbroken picture here. Amongst the crops I've included the old half-frame 35mm system, which had an unusual 18x24mm vertical format, and the 2/3 sensor used in certain compact cameras. The latter is just for reference, although the former is potentially useful as there was a Nikon-Pen F adapter, and so the lens I used could, in theory, be mounted on a Pen F.
Right, I'm warmed up now.