Sony is upgrading its thin T-series digital still camera line with a new model that packs a larger display with touchscreen.

The DSC-T200 hasn't been officially announced by Sony yet but details of the camera were posted to its Sony Canada online shop over the weekend.

The overall design of the camera isn't much changed from the current T100 model so on first glance it looks similar. However, closer inspection at the rear reveals some changes. The buttons present along the right-hand side of the 3in display on the current T100 are gone and in their place a larger 3.5in widescreen display takes up the entire back face of the camera.

So how to navigate the menus with no buttons? Sony has fitted a touchscreen on the 3.5in display that means the backpanel is clear of everything else.

A 3.5in display with touchscreen matches Apple's iPhone but a lot of the tasks and functions that can be carried out are very different. Sony's screen doesn't appear to support two-fingered touch - the one trick that makes the iPhone's touchscreen so special - but can be used to work a variety of functions. For example, in "touch-it shooting" a tap of an object on the screen will focus the camera on that object while when viewing pictures the screen is used to navigate and even paint on photos taken earlier.

Other functions include a "smile shutter" that goes a step beyond the face detection modes common on cameras today. The DSC-T200 won't just find faces in the image and focus on them but in this mode it won't take a picture until it sees all smiles.

Major specifications are similar between the T200 and T100. Both have an 8.1Mp image sensor capable of taking pictures up to 3,264 x 2,448 resolution and in front of the sensor sits a 5x optical zoom lens. It has the same Bionz processing engine.

The camera measures 93.5mm x 59.3mm x 20.4mm and weighs 160 grams.

There's no word on when it will be available or the price. The current T100 that it seems destined to replace costs around £210 in the UK.