Focussing or focusing?

[ilovemyflipflops]

I'm confused.

I would always spell it focusing, but on the Which? site they have spelt it focussing???

Picture quality is made up of many things, focussing sharpness and accurate colour reproduction being just two. We measure picture quality with custom white balance mode - as this gives the best results.

5 million hits for focussing
29 million for focusing.

I think I'd agree with you

...if I were to consume another bottle of Leffe, then focussing would seem correct.

...yet another, and ffoccusssing would probably seem fine, too.

Otherwise, I would think focusing to be correct.

I think my computer's spellcheck insists on 'focussing' so maybe it's an American thing (as everything is with spellcheck)?