The Sigma 70-300mm f/4-5.6 APO DG Macro and 70-300mm f/4-5.6 DG Macro both incorporate a built-in motor, which allows autofocus with all Nikon cameras.

Sigma explains: "The Nikon D40, D40x and D60 cameras cannot fully support the original Nikon lenses, as there is no AF motor built into these cameras, therefore they require a motor built into the lens to achieve autofocus.

"Many people are unaware of this until they have purchased their new Nikon DSLRs. The inclusion of the built-in motor in these two new lenses allows autofocus with all Nikon cameras."

As well as this key feature, these lens also incorporate a macro feature with maximum magnification 1:2 at the 300mm focal length.

The APO lens has been designed to provide extra provision against colour aberration but both lenses use a new multi layer lens coating, which reduces flare and ghosting.

A magnification scale showing focusing distances and reproduction ratios is engraved on the lens barrel of both of the new models.

The 70-300mm f/4-5.6 APO DG Macro is priced £199.99 while the 70-300mm f/4-5.6 DG Macro is cheaper at £149.99.

Key features at a glance:
- Minimum aperture: f/22
- Minimum focusing distance: 150cm
- Lens construction: 14 elements in 10 groups
- Maximum magnification: 1:4.2
- Angle of view: 22.9°- 5.4°
- Weight: 545g
- Dimensions: 76.5mm(D)x119.5mm(L)