Background Blur

Technique

Making the subject pop.

I have referred to the need to blur backgrounds in pictures made with short focal length lenses often. As cameras get smaller, focal lengths shorten. The 35mm FFE lens in the iPhone 4S, for example, has a focal length of but 4.3mm, meaning just about everything is always sharp. At a given aperture, depth of field is solely a function of focal length, having nothing to do with sensor size.

To put this in perspective, the 50mm FFE lens on a full frame 35mm camera or DSLR become 150mm on a 4″ x 5″ sheet film monster, 80mm on a 6×6 medium format Hasselblad, 25mm on an MFT body and just 6 mm on the typical cell phone with its microscopic sensor. Compared to a 6mm, the depth of field of a 150mm lens is miniscule – everything is in focus with the former, little is with the latter. So selective focus on small cameras, absent help from software, is not going to happen ‘in camera’, yet.

If a picture is worth a thousand words an instructional video is an order of magnitude more efficient, so I have made a brief video explaining how to confer background blur using Photoshop CS5, which you can see by clicking the image below. While I start and end the process in Lightroom3, that’s not a required part of the workflow. Use whatever database you like for storage.

And remember, the only people who will know you used this technique will be those you tell in advance.

Click to view the 8 minute video.

One day this technology will be built into software in cameras. The user will be able to restrict the zone of sharpness to the main subject. Cameras already have face recognition. Selective focus is a rational extension of this thinking. Meanwhile, PS CS5 does just fine.

The iPhone 4S does San Francisco

iPhone, Photographs

How good a street snapper is it?

Test charts never did cut it for this street snapper. Real world use and responsiveness turn my crank. So, with that view in mind, I ventured to SF from the south bay, the iPhone 4S’s hotspot providing wifi for the iPad so that I could do my day job on the train there and back.

The iPhone is not going to win any prizes for ergonomics and, frustratingly, I found myself activating the movie slider on more than one occasion until I got the hang of how to hold the gadget right, neither going into movie mode or obscuring the lens. I learned to hold it in the left hand just so, with the camera on, and it was then easy to raise to face level, squint and shoot. I used the Volume ‘+’ button for the shutter release, in preference to the awful touch button on the screen which is an ergonomic nightmare.

What made the whole experience a (relative) joy is the responsiveness of the shutter release which has minimum delay and short time between snaps. Just for fun I tried to see how fast I could shoot and managed 24 snaps in 15 seconds, without trying too hard. Not half bad! Those were all garbage of course, as is typical for machine gun shooting. But one or two others worked out, helped by the strange unobtrusiveness of the iPhone, as your subjects think you are messing with a phone rather than taking their picture. In many respects, now that it has a half-decent camera, the iPhone 4S is the least obtrusive street snapper I have used. As a matter of interest, I consistently found portrait orientation easier than landscape.

Where you see blurred backgrounds they are courtesy of Photoshop CS5 and those thinking of writing me about bokeh or some such nonsense should spare themselves the effort. Bottom line, post processing blur works and it works superbly. It’s hard to relate with a straight face but there are dorks out there who get off on studying the unsharp bits ….

Confused. Obviously an Android user. On Maiden Lane.

Yerba Buena Moscone Center carousel.

Union Square. This lady bears a striking resemblance to Georgia O’Keefe.

Ad doubtless sponsored by knee and back surgeons.

Yuerba Buena colors.

Alone.

Machismo. A lovely warm, masculine face.

Carousel horse.

Chez Mondrian. Off Brannan Street.

The iPhone has got what it takes for street snaps and not too many excuses are called for.

Some of the above were processed lightly in LR3 with background blur added in PS CS5.

Lunch after all this exertion? Why at the South Park Cafe of course!

Pork, dates, a rich sauce and mash. iPad testifies that this was a deductible business trip! Mmmm!

Fellow diners.

Bill Atkinson

Book reviews, Photographers

Book review.

Click to order.

As you are reading this on a computer you are a user of Bill Atkinson’s work, whether you know it or not. You see, Bill was the designer of the original Macintosh graphical user interface almost three decades ago, building on the work done by Xerox at PARC (who were clueless as to what they had) and it’s one used by every Mac and PC today.

But chance does not distribute talent evenly, so in addition to being one of the greatest software engineers of our time, Bill can also lay claim to being an immensely talented photographer.

‘Within the Stone’ is a picture book of 72 photographs of naturally occurring stones. That’s the prosaic description. The reality is that this is simply gorgeous abstract photography, conveyed through the best color reproduction in any book I have seen. It’s not enough that Bill researched his subject over many years and migrated from medium format film to a large sensor scanning digital back to make his pictures. In the process he got deeply involved in researching the reproduction of color on paper and to say that the result is a revelation simply fails to do it justice.

Until now the touchstone for me of abstract photography of naturally ocurring colors and shapes has been Roy Hamman‘s superb Boatscapes, pictures of weathered boat hulls, four of which I am proud to say hang on the dining room wall here. Well, Roy finally has some competition!

If you buy the book, please buy it from Bill directly, not from Amazon. This is a labor of love and I would bet it’s a big money loser for the photographer. Support the arts for just a few dollars more than the WalMart of online sales demands. And, as you might expect of the designer of the Mac’s elegant interface, the packaging is perfect too, with the cardboard shipping container’s flaps overlapping just so, preventing a careless knife from damaging the contents. But then you probably would expect no less from Bill Atkinson, a man not given to doing things by halves.

Just walking the pup

iPhone, Photographs

Um, where’s my camera?

One of the toughest things about the iPhone 4S is that you have to keep reminding yourself that there’s a very capable camera with you at all times.

These were snapped on yesterday evening’s walk with Bert, the resident Border Terrier.

American. Truck. iPhone 4S.

Setting sun.

Dinner. Food. Art.

First two processed in Snapseed, the last unprocessed. All snapped on the iPhone 4S.

The iPhone 4S – Part III

iPhone, Photographs

Some snaps and observations.

When my second AppleTV refused to update over-the-air to AppleTV OS 4.4.1, and as I did not have a micro USB cable to do it over iTunes, I decided to take it to the Genius Bar at the local Apple Store and let the geniuses have at it. While they milled about, humming and hawing, I got to taking a few snaps in the melée that is the Burlingame store.

Once you learn to keep your finger away from the lens, the 4S is a more than decent snapper. Shutter lag is minimal, I have learned how to switch the flash to On-Off-Auto with the screen touch control and face detection shows a green rectangle to tell you what is being focused on. A touch changes the area of choice if that is wrong. Inter-snap delay is very short and there is no meaningful shutter lag. You can bang away at up to two pictures a second with ease.

Because the focal length of the lens (35mm FFE) is a very short 4.28mm, everything is mostly sharp all the time, though the f/2.4 fixed aperture does make touch focus useful for closer subjects.

On the way to the store we first encountered the parrot man in the street:

Parrot man. 4S, 1/120, f/2.4, flash, ISO 125.

A bit of lens flare is visible here around the red cap, though it may be from thumbprints on the lens as much as anything. Something to look out for – or to exploit for certain subjects. Nothing quite like a good greasy thumb to give you that ethereal look!

Nothing wrong with the definition in the above picture:

Parrot Man – detail.

Down the road my son Winston had to have a snap of the ghoul on the local restaurant’s wall – this is completely unretouched:

Ghoul. Picture by Winston Hofler, aged 9. 4S, 1/120, f/2.4, ISO 125.

Where Winnie saw a ghoul, I saw a ghoulish business which thinks nothing of stealing from Americans daily:

Bankster ghouls. 4S, 1/120,f/2.4, ISO 80.

Once in the Apple Store, pups were everywhere to be seen while water damaged keyboards and dropped iPhones were being attended to.

Pup at the Genius Bar. 4S, 1/20, f/2.4, ISO 125.

And another:

Another pup. 4S, 1/20, f/2.4, ISO 125.

Apple likes to get ’em young, and there was a plenitude of snap opportunities in the kids’ play area:

Trying the iMac. 4S, 1/20, f/2.4, ISO 100.

In the next snap, I zoomed in using the un-pinch gesture to see what the quality would be like. The answer is that whereas most of the above will print well at 13″ x 19″, this one starts to break up at 8″ x 10″.

Intent. 4S, 1/20, f/2.4, ISO 100.

Don’t be fooled by those blurred backgrounds. These were done in Photoshop CS5 using the Magic Outliner, Refine Edges and Filter->Lens Blur. But then you wouldn’t know that unless I told you! You can see just what a great job Adobe has done in coding this technology in the close-up of the Parrot Man’s whiskers and the young blonde girl’s hair, above. It takes seconds to do and you can bet this code will be in-camera before too long.

The Auto White Balance in the iPhone 4S beats the pants off that in the Panny G1 and G3.

The funky handling of the 4S takes some getting used to, the screen is awful in bright daylight and the camera is better than 99.9% of photographers out there, most of whom seem to contribute to the fora at DP Review. The remaining 0.1% of us actually take pictures.

That AppleTV? Turned out to be a dud so Apple replaced it, no questions asked, doing the software upgrade on the replacement for me in the store. Can’t grumble – time wasted being more than repaid by some great picture opportunities. And because everyone thinks you are futzing with your phone, no one takes any notice. That’s worth a lot. Now I can enjoy wireless Mirroring from the iPhone 4S, when it’s not being used to take snaps or make calls.