Tuesday, March 05, 2013

Blurry Backgrounds, Big Sensors and Bokeh

Blurry Backgrounds, Big Sensors and Bokeh, article.

David Pogue attempts to research and explain the tricky issue of whether bigger sensors give softer backgrounds.

Photo by me. Olympus OM-D, Olympus 45mm 1.8 at full opening. About 400 ISO.


John Krumm said...

Pogue can sound kind of glib and his love of heavy bokeh is right in the mainstream, which irritates camera-techies who use smaller sensor cameras like the m-43 system. No biggie.

David Evans said...

Pogue writes "The smaller the sensor, the wider the lens". That's a strange way to put it. What is true is that a smaller sensor needs a shorter focal length lens to give the same field of view. For instance a 50mm lens on a full-frame camera has the same field of view as a 25mm lens on a 4/3 camera, which has a sensor half the linear size. If you put that 25mm on a full frame sensor it would be regarded as a wide angle lens, but that's not what it's doing on the 4/3.

John Krumm said...

One way to look at it is that the bokeh is always the same with the same lens, but as you say, the field of view changes. Put a 50mm lens on a tiny cell phone sensor and it's quite the telephoto, but it has the same bokeh as on a full frameand as as a wide angle 50mm lens on a medium format.

Bruce said...

The opposite of blurry backgrounds is context. If it took big expensive cameras to get more context, then manufacturers would encourage everyone to obsess about that. The obsession with bokeh is one manifestation of the desire of camera manufacturers to make a lot of money.

When I see a lot of blur in photos I tend to think of eye problems and eye operations needed to fix them. Not pleasant thoughts.

Eolake Stobblehouse said...

With the majority of photos, deep DoF is often desired. However, in portraits on location and fashion or figure work, or artistic effects, a shallow one is wonderful.

With the right lens though, Micro Four Thirds is a big enough format to get enough blur for almost anybody's taste.

emptyspaces said...

M43 has some great lenses, like the 45/1.8 and 75/1.8, that make blurring backgrounds a cinch.

Get close, and use the longest focal length possible, and you can blur backgrounds with almost any camera (it's tough with an iPhone, however).

Pogue, along with a preponderance of online commenters, associate bokeh with the amount of blur, whereas it is a term that is meant to describe the quality of the blur, rather than the amount.

And it is not always advantageous to completely blur the background - there are plenty of times where you want enough blur to gain separation, but keep enough detail to provide context/detail in your composition. Plus there's always a balancing act between how much you want in focus and how much you want blurred (like in a portrait, where you want the nose and eyes in focus, but the background blurred).

I'm guessing that many folks associate out-of-focus backgrounds with "professional" results, but you can achieve that effect with any plastic 50mm lens quite easily.

I don't think Pogue is wrong, but he will probably confuse some of his readers that want to achieve the shallow DOF effect. Just get as close as you can to your subject and see how that works. Even with small-sensor P&S cams you can blur the background some (especially if you engage the macro focus function).

Eolake Stobblehouse said...

"Pogue, along with a preponderance of online commenters, associate bokeh with the amount of blur, whereas it is a term that is meant to describe the quality of the blur, rather than the amount. "

Yes, sadly it's the fate of anything which takes more than two sentences to explain that it will be distorted and misunderstood if it reaches mainstream consciousness.

Even something as simple as: "No, Frankenstein is the scientist, not the monster" was too sophisticated a thought to penetrate public awareness.

And I'll bet that for the majority of folks it would take a lot of show-and-tell to make them see, if possible at all, the difference between "good" and "bad" bokeh. And most wouldn't give a flying fork.

Ken said...

It is also confirmed with some of the small compacts which produce incredible depth of field on macro. Agree, the M43 cameras can produce nicely out of focus backgrounds.

geoff belfer said...

It all comes down to the "Circle of confusion". Never has a scientific term been more aptly named i think!

Eolake Stobblehouse said...



The Sony RX100, amazing camera, is the only real breast-pocket-sized camera I know which can make decently blurred backgrounds. I think it is a great balance overall in size, both body- and sensor-.