Circles of Confusion

Long before I worked on the web, I specialised in training photographers how to use large format, 5×4″ and 10×8″ view cameras – film cameras with swing and tilt movements, bellows and upside down, back to front images viewed on dim, ground glass screens. It’s been fifteen years since I clicked a shutter on a view camera, but some things have stayed with me from those years.

In photography, even the best lenses don’t focus light onto a point (infinitely small in size) but onto ‘spots’ or circles in the ‘film/image plane’. These circles of light have dimensions, despite being microscopically small. They’re known as ‘circles of confusion’.

As circles of light become larger, the more unsharp parts of a photograph appear. On the flip side, when circles are smaller, an image looks sharper and more in focus. This is the basis for photographic depth of field and with that comes the knowledge that no photograph can be perfectly focused, never truly sharp. Instead, photographs can only be ‘acceptably unsharp’.

Acceptable unsharpness is now a concept that’s relevant to the work we make for the web, because often – unless we compromise – websites cannot look or be experienced exactly the same across browsers, devices or platforms. Accepting that fact, and learning to look upon these natural differences as creative opportunities instead of imperfections, can be tough. Deciding which aspects of a design must remain consistent and, therefore, possibly require more time, effort or compromises can be tougher. Circles of confusion can help us, our bosses and our customers make better, more informed decisions.

Acceptable unsharpness

Many clients still demand that every aspect of a design should be ‘sharp’ – that every user must see rounded boxes, gradients and shadows – without regard for the implications. I believe that this stems largely from the fact that they have previously been shown designs – and asked for sign-off – using static images.

It’s also true that in the past, organisations have invested heavily in style guides which, while maybe still useful in offline media, have a strictness that often fails to allow for the flexibility that we need to create experiences that are appropriate to a user’s browser or device capabilities.

We live in an era where web browsers and devices have wide-ranging capabilities, and websites can rarely look or be experienced exactly the same across them. Is a particular typeface vital to a user’s experience of a brand? How important are gradients or shadows? Are rounded corners really that necessary? These decisions determine how ‘sharp’ an element should be across browsers with different capabilities and, therefore, how much time, effort or extra code and images we devote to achieving consistency between them. To help our clients make those decisions, we can use circles of confusion.

Circles of confusion

Using circles of confusion involves plotting aspects of a visual design into a series of concentric circles, starting at the centre with elements that demand the most consistency. Then, work outwards, placing elements in order of their priority so that they become progressively ‘softer’, more defocused as they’re plotted into outer rings.

If layout and typography must remain consistent, place them in the centre circle as they’re aspects of a design that must remain ‘sharp’.

When gradients are important – but not vital – to a user’s experience of a brand, plot them close to, but not in the centre. This makes everyone aware that to achieve consistency, you’ll need to carve out extra images for browsers that don’t support CSS gradients.

If achieving rounded corners or shadows in all browsers isn’t important, place them into outer circles, allowing you to save time by not creating images or employing JavaScript workarounds.

I’ve found plotting aspects of a visual design into circles of confusion is a useful technique when explaining the natural differences between browsers to clients. It sets more realistic expectations and creates an environment for more meaningful discussions about progressive and emerging technologies. Best of all, it enables everyone to make better and more informed decisions about design implementation priorities.

Involving clients allows the implications of the decisions they make more transparent. For me, this has sometimes meant shifting deadlines or it has allowed me to more easily justify an increase in fees. Most important of all, circles of confusion have helped the people that I work with move beyond yesterday’s one-size-fits-all thinking about visual design, towards accepting the rich diversity of today’s web.