Mirrorless cameras like Sony's well-loved NEX series represent the fastest-growing segment of the photography market, but you wouldn't know it from looking at Nikon's latest financial report. The Japanese giant that has traditionally been at the forefront of camera innovation reports disappointing sales of its mirrorless models in Europe and the US.

Yasuyuki Okamoto, head of Nikon's Imaging team, explains to Reuters that in those regions "the ratio of mirrorless to SLRs hasn't grown at all, unlike in Asia, where it's quite popular with women because it's light." Alongside Canon, Nikon remains a firm favorite among buyers of fully fledged (and bulky) DSLRs, however neither company has yet managed to figure out how to reproduce that success with more portable interchangeable-lens cameras.

Because of the struggles of Nikon's 1 System mirrorless cameras, the company's had to cut its profit forecast for this financial year and Okamoto warns that its product mix in certain markets might have to be reconsidered. Provided that reconsideration also includes a move to bigger sensors and smaller price tags, the Japanese camera maker should still be quite capable of claiming a spot among the mirrorless leaders.