Canon M135mm f/2.5
Canon · Canon 7 bayonet · 1958 · Gauss-derived, 6e/4g
Also known as: Canon M135mm f/2.5 · Canon 135mm f/2.5 Mirror Box · Canon M 135mm f2.5 · Canon 135/2.5 M
Variants & identification
| Variant | Mount | Years | Serial ranges | Production |
|---|---|---|---|---|
| Canon M135mm f/2.5, Mirror Box 2 | Mirror Box 2 (three-lug bayonet) | 1958 | — | No figure published |
- The Mirror Box (1957) screws into the body's 39 mm thread and holds a mirror that flips up on a double cable release; its lenses focus by their own helicoid or by a bellows. The Mirror Box 2 (1958 per lens-db and the museum's M-lens dates; 1961 per Leica Copies Japan) clips onto the Canon 7's outer bayonet and takes its own three-lug lenses — the M135 and M200 — and the 400 to 1000 mm heads through an intermediate tube and Bellows R. The two boxes' lens mounts do not interchange (Leica Copies Japan).
How to tell them apart
Canon M135mm f/2.5, Mirror Box 2:
- Marketed July 1958, ¥53,000 · 500 g · 58 mm filter · stops to f/22 · 13 blades
- Marked M; three-lug bayonet for the Mirror Box 2 only; 58 mm filter; 500 g; own focusing helicoid
Specifications
- Formula
- Gauss-derived, 6e/4g
- Construction
- 6 elements / 4 groups
- Aperture range
- f/2.5–f/22
- Diaphragm blades
- 13
- Min. focus
- 1.5 m
- Weight
- 500 g
- Filter
- 58 mm
- Years manufactured
- 1958
- Country
- Japan
- Original price
- ¥53,000 (July 1958, Canon Camera Museum) (today ¥333,000)
What reviewers say
No reviews aggregated yet — this family is still in the research queue. Written one? We'd love to index it.
History
The fast 135 for the reflex housing: six elements in four groups, marketed in July 1958 at ¥53,000, 500 grams, marked M for the Mirror Box 2. It mounts on the box’s three-lug bayonet and focuses with its own helicoid, the box’s mirror giving the reflex view a rangefinder cannot at this speed and length.
It is the same optical idea as the R and FL 135mm f/2.5 for the Canonflex, which is what the Canonflex’s arrival in 1959 made of the whole mirror-box project.
This history is AI-written, from the sources listed at the foot of the page. Where the record is silent it says so rather than filling the gap — but no human wrote these sentences.
Example photos
Sample photo wanted — shot with a Canon M135mm f/2.5? We'd love to feature it (with credit).
Live listings
Listings updated 2026-09-11. Links go to the shop or marketplace that carries the item.