Quote Originally Posted by DJ 86 View Post
in this image, at 2.8F, why the focus is not very tight?? i can see the background is not totally out of focus. and landscapes are clicked at smaller apertures for large span in focus, then how do we utilise big aperture?
can i see some more examples where wide lenses are used with big apertures?
DJ, this shot focused on a very near-field object. Given the focal length the statue may have only been a foot from the lens. The fact that the building is recognizable as anything other than a blur is a result of using such a short focal length lens.

If someone were to frame the same scene of the statue with a telephoto at the same f/# the magnified blur of the building would have been unrecognizable as such. Each style of photo has its appeal. That's the artistic portion of photography.

Moving to SLR's you're leaving the world of point-and-clicks with micro-sized sensors. SLRs are far more capable but also more complicated and difficult to drive well. The SLR community does not speak of magnification powers per se. Instead everything is discussed in terms of the framing of the image relative to a 35mm negative. Any given focal length will capture light from a given arc in front of the lens. That's what ends up on the sensor. After taking that into account then the f/# and focal length and object/background will dictate what's in or out of focus.

If you're truly only interested in shooting landscapes that cover a wide angle with a narrow aperture then pretty much any lens with f < 35 mm will do. Obviously the more expensive the lens the better the image quality. However, most of us are not so single-minded in out photography desires. So having a mixture of focal lengths and the option for wide apertures allows flexibility.