Specifications#
- Brand
- Pentax
- Model
- Super-Multi-Coated Takumar 400mm f/5.6
- Lens type
- Super-telephoto prime
- Focal length
- 400 mm
- Maximum aperture
- f/5.6
- Image circle
- Full frame (36×24 mm)
- Mount(s)
- M42 screw mount
- Projection
- Rectilinear
- Lensfun correction profile
- Yes — distortion/vignetting/TCA
Equivalent focal length on different cameras#
Field of view and depth-of-field equivalence when this lens is used on bodies with different sensor sizes (natively or via an adapter).
| Camera format | At 400 mm | Equiv. aperture (DoF) |
|---|---|---|
| Full frame | 400 mm · 6° | f/5.6 |
| APS-C | 600 mm · 4° | f/8.4 |
| APS-C (Canon) | 640 mm · 4° | f/9.0 |
| Micro Four Thirds | 800 mm · 3° | f/11.2 |
Depth of field & background blur#
Computed on its native Full frame format (CoC 30 µm). “Blur @2 m” is the size of an out-of-focus point at infinity, as a percentage of frame width, with the subject at 2 m — a simple bokeh index. Full table: 400 mm f/5.6 on full frame.
| Focal | Aperture | at 1 m | at 2 m | at 5 m | at 10 m | Hyperfocal | Blur @2 m |
|---|---|---|---|---|---|---|---|
| 400 mm | f/5.6 | 0.1 cm | 0.7 cm | 4.8 cm | 20.2 cm | 953 m | 49.6% |
| 400 mm | f/8 | 0.2 cm | 1.0 cm | 6.9 cm | 28.8 cm | 667 m | 34.7% |
Handheld & night-sky limits#
NPF assumes typical 20–24 MP sensors (≈6 µm pixels on full frame, ≈3.9 µm on APS-C, ≈3.3 µm on Micro Four Thirds).
| Body | Min. handheld shutter (longest focal) | 500 rule at 400 mm | NPF at 400 mm, f/5.6 |
|---|---|---|---|
| Full frame | 1/400 s | 1 s | 1 s |
| APS-C | 1/640 s | 1 s | 1 s |
| APS-C (Canon) | 1/640 s | 1 s | 1 s |
| Micro Four Thirds | 1/800 s | 1 s | 1 s |
Compatible cameras#
Bodies in our database with a native M42 screw mount mount.
Adapt it to other systems#
Frequently asked questions#
Is the Pentax Super-Multi-Coated Takumar 400mm f/5.6 full frame?
Yes — it covers the full 36 × 24 mm frame.
What is the Pentax Super-Multi-Coated Takumar 400mm f/5.6 equivalent to on APS-C?
On a 1.5× APS-C body it frames like 600 mm, and like 640 mm on Canon APS-C.
What is the Pentax Super-Multi-Coated Takumar 400mm f/5.6 good for?
As a super-telephoto prime it suits birds, wildlife and field sports from a distance.
Sources & licences#
- Lensfun lens database — CC BY-SA 3.0
Last updated October 03, 2026 · How we calculate · Sources