400mm · APS-C
Super telephoto
- Diagonal angle
- 4°
- Horizontal angle
- 3.4°
- Vertical angle
- 2.2°
- Crop factor
- 1.53×
- 35 mm equivalent
- 612mm
- Frame width at 2 m
- 0.12 m
One step smaller than full frame; the same lens covers a narrower field and looks longer.
For subjects you cannot approach — birds, stadiums. Extremely sensitive to shake.
Same field of view elsewhere
A different sensor needs a different focal length to frame the same scene.
Nearby focal lengths
How to read this
- Focal length alone does not fix the angle of view — the same 50 mm sees less on a smaller sensor.
- The crop factor is the sensor diagonal divided into the 35 mm diagonal; multiply the focal length by it for the equivalent.
- Longer lenses magnify shake. Handheld, a shutter speed faster than one over the equivalent focal length is the usual rule.
- A wider angle is not purely more scene: the edges stretch, so faces belong near the middle.
Frequently asked questions
Q. What angle of view does 400 mm give on APS-C?
4° diagonally, 3.4° horizontally and 2.2° vertically.
Q. What is 400 mm in 35 mm terms?
612 mm — the focal length multiplied by this sensor’s crop factor of 1.53.
Q. What is this combination good for?
It falls in the super telephoto group. Standing two metres away, it frames 0.12 metres across.
Q. How do I get the same framing on another camera?
A different sensor needs a different focal length; the equivalent combinations are listed further down this page.