Quick answer
The Beroflex 400mm f/6.3 is a super telephoto prime lens covering 400mm at f/6.3 for the M42 mount. Its smaller maximum aperture favours daylight shooting and keeps the lens compact.
About this lens
This 400mm f/6.3 manual-focus telephoto prime lens from Beroflex fits M42 mount cameras. It brings distant subjects closer for sports, wildlife and events.
Beroflex 400mm f/6.3 specifications
What can you shoot with the Beroflex 400mm f/6.3?
At 400mm this is a super telephoto prime, which typically suits:
- Wildlife and birds
- Motorsport and field sports
- Distant subjects and the moon
Its smaller maximum aperture favours daylight shooting and keeps the lens compact.
Full-frame equivalent and field of view
Calculated from the focal length and crop factor (adapted mount, so sensor size depends on your camera). Not measured.
| Sensor | Crop | Equivalent | Horizontal FOV | Diagonal FOV |
|---|---|---|---|---|
| Full frame | 1.0x | 400mm | 5.2° | 6.2° |
| APS-C | 1.5x | 600mm | 3.4° | 4.1° |
| Micro Four Thirds | 2.0x | 800mm | 2.6° | 3.1° |
Frequently asked questions
What mount does the Beroflex 400mm f/6.3 use?
It uses the M42 mount, so it fits M42 cameras directly and can be used on other systems through a mount adapter.
What is the focal length of the Beroflex 400mm f/6.3?
It is a fixed 400mm lens with a maximum aperture of f/6.3. That makes it a super telephoto lens.
Is the Beroflex 400mm f/6.3 a prime or a zoom lens?
It is a prime lens with a fixed 400mm focal length. Primes usually open wider than zooms; this one opens to f/6.3.
What is the Beroflex 400mm f/6.3 equivalent on a crop sensor?
On APS-C (1.5x crop) it frames like 600mm on full frame, with a 3.4° horizontal and 4.1° diagonal field of view. On Micro Four Thirds (2x crop) it frames like 800mm on full frame, with a 2.6° horizontal and 3.1° diagonal field of view. These figures are calculated from the focal length and crop factor.
Alternatives for M42 from other brands
All M42 lensesSame mount, overlapping focal range, closest maximum aperture first.
