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I was wondering how it is possible to take a picture like this.

Please have a look here for some example pictures. The flower is sharp, and everything else looks like taken with a long shutter.

Is that even possible, or do you think it's Photoshop-edited?

I asked the photographer about the lens, and it's a Minolta RF Rokkor 250mm f5.6.

mattdm
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gsharp
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    Beautiful photos. Not only is the DOF great, but so is the lighting. – Craig Walker Aug 04 '11 at 23:42
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    Unfortunately, those photos (at least the ones I checked) are copyrighted according Picasa's image info. As such, they're not legal for embedding in Photo.SE. Posting hyperlinks to them is acceptable though. – Craig Walker Aug 04 '11 at 23:45
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    The first one uses a mirror lens. I can tell by the pixels. – eruditass Aug 05 '11 at 01:52
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    To expand on @Eruditass's comment, by "Mirror Lens" he means a Catadioptric Telephoto ( http://en.wikipedia.org/wiki/Catadioptric_system ), and I believe he is right. Catadioptric lenses produce a distinct "donut" shaped Bokeh. – Fake Name Aug 05 '11 at 06:03
  • It does look like the blur from a mirror lens. In that case, it's unlikely that the aperture is wider tha f/5.6 or f/8 (since that's usually a physical limitation of such lenses); the shallow depth of field must be due to a large sensor + long focal length + relatively close subject. Read more here. – mattdm Aug 05 '11 at 12:03
  • @Eruditass: the pixels? – mattdm Aug 05 '11 at 12:04
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    @mattdm: Eruditass is riffing on an internet meme: http://knowyourmeme.com/memes/this-looks-shopped – Craig Walker Aug 05 '11 at 14:08
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    Ahhhhh, got it. So many memes, so little time. – mattdm Aug 05 '11 at 15:42
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    Minolta RF Rokkor 250mm f5.6 is a mirror lens, hence the funky donut bokeh. – rfusca Aug 05 '11 at 16:57

3 Answers3

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You're confusing the blur in the background that's due to having a shallow depth of field with motion blur from a long exposure. The exposure length has pretty much nothing to do with it here.

It's all about the aperture. (And if you want to change your composition, the distance to the subject.)

Depth of field has been covered in great length on the site otherwise, so there's no need to repeat it all - but basically you'll want to get as close to your subject as possible, with the widest aperture (lowest f number) to maximize your subject isolation. Moving back or making your aperture smaller (bigger f number) will make the background more in focus.

If you only have a point and shoot camera with a small sensor, you'll be unlikely to replicate the subject isolation in these photos.

(Also, given the donut shaped bokeh of the first, its possible it was done with a mirror telephoto lens, which have relatively close focus for their focal length, giving them the ability to do some shots like this)

Community
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rfusca
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  • Thanks for the great explanation. I've tried now about one hour to reproduce the same effect, but as you said my camera has probably a too small sensor to get the same exagerated effect. I thought because of the extreme blurs on this pictures that this woudn't be possible without some extra tricks. – gsharp Aug 04 '11 at 22:06
  • Another name for the mirror lens - Catadioptric or Cassegrain (http://en.wikipedia.org/wiki/Catadioptric). – ysap Aug 04 '11 at 23:46
  • Extension tubes can be handy for reducing the DoF without either going super-wide or macro: I think this (http://www.flickr.com/photos/otterchaos/3407392743/) came from a nifty-fifty with a couple of Kenko tubes added. – Mike Woodhouse Aug 05 '11 at 10:30
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Looks like it's been shot with a wide aperture (low f number, like f/2.8), from a close distance, with a camera that has a large sensor -- the combined effect is a shallow depth of field, as demonstrated there.

To reproduce, put your camera in aperture priority mode (Av on a lot of cameras) and choose a wide aperture (head for f/2.8 rather than f/22) and get shooting.

Rowland Shaw
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    This is the best how-to answer, but I suggest that you also read the explanation of @rfusca who explains WHY this occurs. – nchpmn Aug 04 '11 at 21:07
  • I'm pretty sure the aperture was smaller than f/2.8. Most of the foreground flower is in focus. It's hard to do forensic image decomposition, but if I wanted this effect, I'd choose a slightly longer than normal lens like a 100mm macro, which gives excellent focus fall-off and shoot at around f/4 or f/5.6. At f/2.8 the depth of field is so thin you might get (for example) the tips of the near petals in focus and the rest of the flower blurring. You can see a little of that in the example because half a stop smaller might have brought the back petals into focus. – Steve Ross Aug 05 '11 at 02:28
  • @Steve difficult to say for sure without knowing the exact model of camera (or at least the sensor size) and focusing distance - my guess if the first is around f/2.8->3.5 and the second closer to f/5.6->6.3; The principle for reproducing the effect is the same - get the aperture wide, and start from there as a guide (of course, using a compact camera, f/2.8 would be a bad place to start, given the smaller sensor size, and the much closer "infinity" focal point) – Rowland Shaw Aug 05 '11 at 07:58
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Those photos use a shallow depth-of-field to create a sharp, focused subject and blur the parts of the photo that aren't in the same plane as the subject. Notice in the first photo, the leaves to the left of the flower are also in focus -- these are very nearly the same distance from the lens as the flower, so they're part of that same depth-of-field.

In the second photo, the depth-of-field is shallow (small) enough that the whole flower isn't even in focus -- just part of it is. This technique is used to isolate subjects from backgrounds -- you'll also see it used extensively in portrait photography.

D. Lambert
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