Sigma’s range of ‘Contemporary’ series lenses, such as the Sigma 45mm F2.8 DG DN Contemporary, are all about maintaining a balance between size, performance and price. They’re not smaller versions of the Art series lenses, which are meant to deliver the best possible image quality, regardless of size. With a 55mm filter thread, and weighing 215g ( 7.58 oz), its diminutive size in E-mount nicely complements the Sony a7/9 series and in the L-mount version, maybe also the larger Leica SL and Lumix S1 models, which it has also been designed for. At around £549 / $549 [advertiser links], this all-metal lens is beautifully made. It even comes with…