Feeling frustrated by flashguns? Misfiring autofocus making you anxious? Send your technique and camera questions to digitalcamera@futurenet.com

£6,840/$8,895 (body only)

£1,400/$1,498

£799/$999

Sigma calls its latest superzoom ‘the ultimate all-in-one zoom lens’, but can a 10x zoom be an ultimate anything, asks Damien Demolder

Here are our best-buy bargain second-hand lenses to buy, as selected by the AP team and contributors