This photo was taken in London with a Canon 5D Mark IV, an EF-S 18-135mm f/3.5-5.6 IS STM lens and the new Canon G5. Canon has just announced the G5, which includes a new 16-megapixel A7S APS-C sensor, larger battery, and an extra-long 18-55mm lens. (It also has a dedicated 16-50mm lens that will work with the G5’s 18-55 kit lens).
In this particular shot, the lens is positioned a little above about the top-right of the frame – as you can see, the lens was on a tripod in this particular shot so it could reach infinity focus without the use of an extension tube.
In this case, the only reason for the crop is to increase the effective focal length – the lens has been focused at f/3.5 to get to the 18mm focal length – but there are other advantages of keeping the exposure length longer as well.
First, a 16-megapixel sensor can have a higher resolution than a 13-megapixel sensor, as I’ve shown in my tutorial on taking portraits at wide open aperture with lenses from the full aperture range. When you increase the effective focal length the depth of field increases, although by the definition of “effective” it’s only up to 35% of the original field of view at that aperture – that’s not enough to create an impressive depth of field. Therefore, the wider the aperture the less depth of field we get, and, therefore, the more sharp the image. If we’re in the middle of a scene with many foreground subjects and lots of foreground shadow, the depth of field becomes even more exaggerated. On the other hand, if we are in the foreground of a scene with a light background, the shallow depth of field gets blurred. And this is exactly the case with the full aperture lenses you can use for the 17cm lens (16MP) of the Canon 5D Mark IV: you can still achieve nice depth of field in this case at f/1.4 (8mm), but even then you will barely see the difference if you zoom your camera way out at 1.4.
Second, keeping the focal length longer results in wider depth of field as well – and with these wide aperture lenses, you want to keep the aperture wide enough to keep your subject in sharp focus (the subject should stay in the shot for the entire
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