Posts Tagged ‘depth of field’

Bokeh Bunkum

Friday, November 13th, 2020

I’ve never really understood the hoo-hah about bokeh which has become far too dominant since photography came on the web; it really was not an issue, not even a term photographers had heard of before 1997 and the blame for its introduction can be clearly laid with Mike Johnston, then editor of Photo Techniques (but now author of The Online Photographer blog) who published three articles on it in May of that year, as well as changing its spelling from the Japanes ‘boke’ to reflect its pronunciation for us anglophones. And it was on his blog that I found the link to the video Bokeh Is Overrated by Andrew on the Andrew & Denae channel.

Bokeh is a term to describe the different rendering by different lens designs of out of focus background areas, particularly highlights. The differences become more obvious at wide apertures and with longer focal lengths. Some designs retain a more wiry core, while others are smoother, though the differences can be subtle. The most extreme example of a bokeh that I almost always find unpleasant is the doughnut shaped out of focus highlights produced by all mirror lenses; typically 500mm or more, their mirror design gives these despite the limited apertures – usually f8.

Bokeh has I think become so popular because it gives people a kind of plug-in solution to producing “better pictures”. You don’t need to think but can simply buy a f1.2 lens and use it wide open for your portraits etc. Lazy photography. And now getting lazier still when you can apply it in software after the event or in camera.

Andrew’s experimental study which he describes in his video isn’t really about bokeh, but about out of focus backgrounds and I think all his relevant pictures in it were taken with the same lens but at differing apertures. But its results still show the largely irrelevant nature of the holy grail bokeh quest to actually making better pictures, pictures that other people and not just fellow bokeh-obsessed nerds will prefer.

While the details of the survey which occupy much of the video are a little tedious, and it clearly – as the video and a disclaimer makes clear – is not a scientifically valid survey, its hard to fault the conclusions and advice Andrew gives in the final section of the video, which I hope will do something to cool the bokeh obsession.

Among his conclusions are that the “strength of a photograph is not measured in terms of background blur” and “what is in focus is always more important than what is not in focus” but there is a lot more that makes sense.

There are, as he says, valid reasons to want fast lenses, mainly to work in low light, where as well as for taking images, with cameras that have optical through the lens viewfinders such as DSLRs they give a brighter image. Of course they are far less necessary than used to be the case with film, when ISO 1600 was about as far as we could push; now we have at least 3 stops more to play with. For static subjects we now have image stabilisation which enables us to use much slower speeds hand-held – and as a last resort there are tripods, though I now seldom need to dust mine off.

I do own a f1.2 lens, a Fuji XF56mm short telephoto, but I’m not sure I’ve ever used it wide open. Usually the depth of field is simply insufficient. Stopped down to F2.8 it gets noticeably sharper too. But usually I’ll trade any advantages of a fast lens for the smaller bulk and lower mass and price of an F2.8 or f4 counterpart – and will take the great majority of my pictures between f5.6 and f11, except by accident.

My London Diary : London Photos : Hull : River Lea/Lee Valley : London’s Industrial Heritage : Flickr

All photographs on this and my other sites, unless otherwise stated, are taken by and copyright of Peter Marshall, and are available for reproduction or can be bought as prints.