(Pocket-lint) - In what has been an absolute bumper week for camera launches ahead of the big CP+ photography expo in Japan, Sigma has unleashed its new kit - or rather a new twist on some old favourites.

First up, the Japanese company has the re-branded its flagship DSLR camera, the SD1, which is now known as the Sigma SD1 Merrill. Dick Merrill was the chap who invented the technology that has made the Foveon X3 Direct Image Sensor possible.

"This revolutionary image capture system reflects both the artistic and technological sides of Merrill’s personality," reads a company statement. "As an expression of Sigma’s passion for photography and in honour of Dick Merrill’s genius, we have named the latest generation of the Foveon X3 Direct Image Sensor the Foveon Merrill."

Apart from the name, the camera stays the same. But, don't worry, there are some completely new devices sporting the Merrill moniker by way of the Sigma DP1 Merrill and Sigma DP2 Merrill.

Packing the Foveon Merrill sensor, these beauties take their lead from the original DP1 and DP2 cameras, released back in 2006, the first compacts to boast almost DSLR-size sensors. The megapixel count is up to 46 (4800 x 3200 x 3 layers) which is manageable thanks to a dual TRUE (Three-layer Responsive Ultimate Engine) II image processing engine.

Both the DP1 Merrill and the DP2 Merrill have 3-inch, 920k dot, displays - the difference between the two lies in the lenses. For the DP1 it's a new 19mm f2.8 lens (28mm equivalent), which should make it a darn sight faster than the 28mm-equivalent f4 lens of the previous model. For the DP2 it's a new 30mm f2.8 lens (45mm equivalent) one.

The SD1 Merrill will be available in March; the DP1 Merrill and DP2 Merrill's release details are still to be confirmed.

Writing by Paul Lamkin.