Apr 182010

As promised, instead of a rainy Sunday image, here’s another one of yesterday’s spring impressions, this time from a square in Villach where we had breakfast in the sun.

Again this has been taken with the Nikon 70-300 VR at 300 mm, only this time at minimum focus distance, and that always make for a good blur, even at f5.6.

The Song of the Day is “A Andorinha Da Primavera” from Madredeus’ wonderful 1997 album “O Paraíso: 14 Canções”. No swallows in this image though 🙂

Hear it on YouTube.

  4 Responses to “1283 – La Primavera III”

  1. This is so beautiful it takes my breath away! Love love the colors and the bokeh, too.

  2. I echo how wonderful the colors are. In your comment you said shooting at minimum focal distance would always give a good blur even if at f 5.6. Is that true for all lenses, no matter the focal length? thanks joanlvh

  3. Glad you like it. It’s nothing special compositionally and flowers are such a cliché, but sometimes there is more to a picture than just the question whether it’s art or not. This one simply made my day 🙂

    As to the quality of blur at minimum focus distance (i.e. the minimum distance the lens will focus): In general depth of field is dependent on aperture, focal length and distance from subject to camera, or to be precise, to that point that is exactly the real focal length behind the front element of the lens.

    Most lenses bend and twist the light rays in kinds that make them longer than their focal length. A typical example are 10mm wide-angles for APS C-sized sensors. It’s impossible to build such a short lens for a DSLR, thus they build it longer, typically between 70 and 100 mm, and construct it such that the light gets focused, bundled and sent straight backwards. It’s more complex, but it’s about equivalent to that. Thus effective subject distance of a 10 mm lens is from the subject to a point 10 mm behind the front element of the lens.

    The shorter subject distance is in relation to focal length, the smaller is depth of field. Longer lenses with short minimum focus distances are best for that, the extreme is a macro lens, typically between 50 and 200 mm, frequently focusing down to an inch.

    The second important variable is aperture. The wider it is, the more blur do you get in out-of-focus areas.

    The third point is the relation of focus distance to the distance of out-of-focus areas. Focusing near with a far-off background gives you a better blur than focusing near with an only slightly more distant background.

    All that does not say much about the absolute quality of the blur, i.e. how pleasant it looks. The more glass you have (number of elements in a lens), the bigger the zoom range (if it’s a zoom), the cheaper the lens, the more compromises. Especially when you use a lens in its extremes, i.e. widest aperture, nearest focus distance, there is the potential for anomalies in the way the lens blurs out-of-focus areas. You may see double lines, onion effects on lights, etc, but usually when you get near to the subject and away from the background, the influence of subject distance to background distance ratio gets dominant. You may get a satisfying blur even on an otherwise mediocre lens. In this image I had exactly that condition. The flower was near, the background flowers relatively far off in relation to how near the subject was.

    Some links to read: Ctein on depth of field and Mike Johnston on Bokeh.

  4. Great shot Andreas! Love the bright colors in the beautifully out of focus background!


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