Designed for macro photography, the Sigma 18-250mm f/3.5-6.3 DC Macro OS HSM is the company’s first to use Thermally Stable Composite (TSC).

‘This material is unique to Sigma and has metal-like characteristics,’ says Sigma.

In an interview with Amateur Photographer, a Sigma UK spokesman explained that, essentially, the move aims to allow lenses to be made smaller, and lighter.

The material has been developed in conjunction with a specialist manufacturer, adds the firm in a statement.

‘Traditionally, Sigma uses engineering plastic which is polycarbonate mixed with 20-30% glass.

‘The advantages of this are its high resistance to impact, it’s lightweight and it doesn’t degrade over time.

‘However, the drawbacks are its plastic feel and high dependency on temperature. In differing temperatures it expands and contracts considerably.

‘As a result, a large gap is required between any metal/composite interface to allow for this expansion/contraction in size.

‘The new TSC material has overcome this and is much more stable in varying temperatures.

‘Consequently, a tighter construction can be achieved with thinner and lighter material.’

Features include a close focusing distance of 35cm and a maximum magnification of 1:2.9 (1:2 when used on a DSLR with an APS-C size imaging sensor).

The new 18-250mm is due out in Sigma, Canon and Nikon fits by the end of next week.

Pentax and Sony versions are expected out shortly, according to Sigma Imaging UK.

The lens will cost £499.99.