35mm vs 40mm portrait comparison

What this comparison shows

Both images show the same portrait at the same size. Both cameras stand at almost the same distance, because 35mm and 40mm have a similar field of view. From closer in, 35mm shows more of the room around the person. 40mm has a narrower field of view, so the background looks larger and closer and is easier to simplify.

Start at f/1.4 on the left and f/2 on the right. Then try f/1.8 vs f/1.8, or open both to f/1.4 and f/2. Match depth of field sets the right-hand aperture so the background is as blurred as on the left. Both cameras use the same sensor, so equal f-numbers give a similar depth of field.

At the face framing, 35mm stands 57 cm from the subject. At f/1.4 the sharp zone runs from 55 cm to 58 cm. 40mm stands 65 cm away, and at f/2 the sharp zone runs from 63 cm to 67 cm.

Questions

How far from the subject do you stand with 35mm and 40mm?

In the face framing, 35mm stands 57 cm from the subject and 40mm stands 65 cm. Both cameras stand at almost the same distance, because 35mm and 40mm have a similar field of view.

Which blurs the background more, 35mm or 40mm?

At the same framing, a distant background blurs in proportion to the aperture opening, focal length divided by f-number. 35mm at f/1.4 opens 25.0 mm and 40mm at f/2 opens 20.0 mm, so 35mm blurs it about 1.3 times as much. Close behind the person, the focal length matters less and the f-number more.

Do 35mm and 40mm give a different perspective?

Hardly. Both frame the face from almost the same distance, so perspective and background size match. What changes is how much the background blurs at a given f-number.

Related comparisons

• 24mm vs 35mm portrait comparison
• 24mm vs 50mm portrait comparison
• 28mm vs 35mm portrait comparison
• 28mm vs 50mm portrait comparison
• 35mm vs 50mm portrait comparison
• 35mm vs 58mm portrait comparison

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Also see: depth of field, bokeh, crop factor, lens compression.