Go the dis­tance

Mas­ter hy­per­fo­cal dis­tance and get all your land­scapes sharp from the fore­ground to the hori­zon

NPhoto - - Contents -

Getting your land­scapes sharp from front to back is tricky, but ex­ploit­ing a phe­nom­e­non of depth of field can help you get a tack­sharp scene ev­ery time. Depth of field is the dis­tance ei­ther side of the fo­cal point that is ‘ac­cept­ably sharp’; it’s de­ter­mined by aper­ture, focus dis­tance and fo­cal length, and – cru­cially – it ex­tends twice as far beyond the focus point as it does in front. The point of us­ing hy­per­fo­cal dis­tance fo­cus­ing is to focus at the point at which the depth of field stretches to ‘in­fin­ity’ so that the max­i­mum pos­si­ble amount of the scene ap­pears sharp.

You get a greater depth of field at shorter fo­cal lengths and nar­rower aper­tures, so if you shoot at an aper­ture of f/16 on a 16mm wide-an­gle lens with a full-frame Nikon, the hy­per­fo­cal dis­tance is 50cm. Fo­cus­ing at this point will make ev­ery­thing from roughly half this dis­tance (25cm) to in­fin­ity ap­pear sharp.

Be­fore di­al­ing in your lens’s small­est aper­ture, though, you need to take ‘dif­frac­tion’ into ac­count, as im­ages ac­tu­ally be­come pro­gres­sively softer at nar­row aper­tures due to light be­ing diffracted by the aper­ture blades. This be­comes no­tice­able beyond around f/16 on an APS-C (DX) for­mat sen­sor, or f/22 on a full-frame (FX) one.

You get a greater depth of field at shorter fo­cal lengths and nar­rower aper­tures

Newspapers in English

Newspapers from Australia

© PressReader. All rights reserved.