85mm Portrait

An 85mm renders a face the way portraiture wants it. The camera stands back far enough that the nose stops leading, the cheekbones settle, and the head reads as a shape instead of a perspective problem.

It also removes the room. The background goes soft and far, so nothing behind the person competes with them, which is the second half of what the lens is for.

A head fills the frame from roughly one and a half to two metres away. That distance is what flattens the face, and the flattering part is the distance rather than the glass.

Depth of field is shallow. At f/1.8 on a head-and-shoulders crop the sharp zone runs a few centimetres, so the eyes land and the ears soften. Focus on the near eye and accept that the far one goes.

Backgrounds render larger than they are, because the narrow field of view takes a small slice of the wall and magnifies it. A lamp three metres back becomes a broad soft glow with no lamp left in it.

Use it for interviews, portraits, talking heads and any close coverage where the subject has to dominate the frame.

Skip it when the location matters. An 85mm reduces a room to a wash of colour, so a shot that has to say where somebody is needs a wider length.

A 50mm is a normal lens. It keeps the room readable and renders the face without flattening it. An 85mm stands back, compresses the features and drops the background away.

Match the head size on both and look behind the subject. If you can tell what room it is, you are on the 50mm.

The model returns the crop with a sharp background, which loses half the reason to name the lens. Ask for the background falling soft behind, and say how soft.

The other failure is a wide lens used close to fake the crop. Say the camera stands back at portrait distance, so the face renders flat instead of bending toward the lens.