Bokeh at Small Apertures

Maybe it’s just a cactus in the sun.  Maybe it’s not a cactus – a succulent?  I’m not a botanist and I’m too lazy to use the google.  In any case, I like it.   But technically there is something else going on.  Photo nerds, follow me down.

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What you’ve got is an out-of-focus background.  Bokeh is what people like to call it.  This one was shot with my 24-105 f/4 IS L.  Most of the time when you think of bokeh, it’s fast lenses with huge apertures, and that certainly makes it easy.  When we talked about shaped bokeh, you need an aperture that is physically larger than the shape you put in front of it, so yeah – it helps.  At the same time, you can get this blurred background with slower lenses.  Remember that the lens I used above only goes down to f/4.  If you check out the EXIF info under the picture, you’ll see that this shot was at f/7.1 – what gives, right?

A few tips.  If you can’t drop the aperture, you can do two things.  First, get close to the subject – as close as you can.  This is the part that matters the most.  Even if you have a zoom lens, use your feet.  Second tip is that you want the background to be as far back as possible.  Those are the two elements that are going to help your depth of field here, and that’s all we’re talking about, right?  Bokeh comes from having an in-focus subject with an out-of-focus background.  Smaller apertures (higher numbers) give you a greater depth of field, and it increases with the subject’s distance from the lens so keep the subject close (where your DoF is relatively smaller) and keep your background far (where you have a greater chance of pushing it out of your DoF).

Makes sense?  Good.