Nikon unveiled its first mirrorless cameras on Wednesday, beating its arch rival Canon to the nascent market for small, interchangeable-lens cameras, where other manufacturers have met with mixed success.

Priced at around 70,000 yen ($915) and 105,000 yen, the long-rumored Nikon 1 J1 and Nikon 1 V1 will go on sale on October 20, the company said at a launch at an upmarket hotel in Tokyo's Roppongi, with models, actors and Japanese TV star Takuya Kimura on hand.

A new market is developing among people who feel a compact camera is not quite good enough, Yasuyuki Okamoto, head of the company's imaging division, told reporters, adding that he saw the camera's small size as one of its main appeals.

Nikon and Canon dominate the market for the hefty single-lens reflex cameras used by professional photographers and enthusiasts, and mirrorless cameras pack many of the benefits of those high-end models into smaller bodies.

They have large sensors, giving good picture quality, but no optical viewfinders, enabling manufacturers to keep the camera body smaller and lighter by leaving the mirror out of the structure.

The new format is popular in Japan, where consumers tend to value easily portable products, but has so far sold less well in North America and Europe.

Mirrorless cameras accounted for 31 percent of all interchangeable lens models sold in Japan in 2010, but only 10 percent in the United States, according to research firm IDC.

Global mirrorless shipments reached 2.1 million units in 2010, but IDC is revising its forecasts for 2011, which it says will depend on new entrants and economic conditions.

This is turning into a tricky market trend, said Chris Chute, research manager in charge of digital imaging at IDC. It is clear that while the mirrorless segment is doing well in Japan and a few other countries, it is facing hurdles in the West.

He added that the entry of a big name such as Nikon could lift the whole segment, but said price would be an important factor, specifying the $500-$800 range as most likely to sell well.

We do not see a high-priced mirrorless model having as great a chance of success, he said.

Sony's NEX 5-D is available online for about 44,000 yen, including two lenses.

Shares in Nikon were up 1.2 percent by late afternoon, outperforming Tokyo's electrical machinery subindex's 0.7 percent rise. Rumors about the mirrorless launch have helped lift its share price about 10 percent since September 1.

($1 = 76.450 Japanese Yen)

(Editing by Michael Watson)