Pekka Buttler: 07/2025
Introduction to the Tamron Adapt-a-matic mount:
The Tamron Adapt-a-matic is not – strictly speaking – a lens mount as there has never been a camera that uses the Adapt-a-matic mount, but is instead an intermediate mount. The purpose of such mounts is to allow third party lens manufacturers to easily make their lenses available on a wide range of camera bodies, simply by attaching a suitable adapter to the lens.
Tamron Adapt-a-matic mount specifications and identification
Mount type: 58 mm thread mount (threads on the inner side)
Flange focal distance: 48,5 mm
Sensor Size: 36,0 mm x 24,0 mm (Full frame)
Mount communication:
• Adapt-a-matic lenses are able to respond to aperture stop-down commands (mechanical).
• Adapt-a-matic lenses are NOT able to communicate the selected aperture value nor the lens’ aperture range.
Key Characteristics of Tamron Adapt-a-matic lenses
[1] 58 mm thread mount (Does not protrude. You have to know to look for it)
[2] Orientation pin to help orient adapter
[3] Opening (dark) for adapter’s lever to couple with aperture mechanism lever (silver)
History of Tamron and Tamron intermediate mounts.
Tamron, originally Taisei Kogaku (Taisei Optical Equipment Manufacturing), was founded in 1950 in the Japanese city of Urawa (nowadays Saitama), a bit north of Tokyo. Tamron originally manufactured cameras and binoculars, and while the binoculars sold well, the cameras did less so. In 1957 Tamron started manufacturing camera lenses with the intention of these lenses being used on a wide range of cameras. From the beginning Tamron’s approach was to use an intermediate mount to allow their lenses to be used on as wide as possible a range of cameras.
Tamron has a long history of producing lenses for intermediate mounts as well as designing such mounts, summarised below:
• ‘mini’ T mount (M37x0,75 mm thread), introduced in 1957
• T/T2 mount (M42x0,75 mm thread), introduced in 1962
• Tamron Adapt-a-Matic (breech-lock mount), introduced 1969
• Tamron Adaptall (bayonet mount), introduced 1973
• Tamron Adaptall-2 (bayonet mount), introduced 1980
Generally each new generation of the mount was launched in order to incorporate a functionality that the previous mount did not allow for:
• The switch from the original M37 T mount to the wider M42 T mount was to allow larger rear lens elements (and exit pupils)
• The switch to Adapt-a-Matic was to allow auto aperture
• Going from Adapt-a-matic to Adaptable allowed the lens to communicate its selected aperture
… and so on.
Tamron had a lot of success with its focus on producing lenses for intermediate mounts, but the increase of electronic lens-body communication and the advent of autofocus lenses forced Tamron to start producing their lenses separately for each mount. What is noteworthy is that Tamron is one of the few third party lens manufacturers to have remained in the business, while many (most) others have had to throw in the towel.
Adapting Tamron Adapt-a-matic lenses
If you intend to adapt your Tamron Adapt-a-matic lens to a dSLR…
There are original Tamron Adapt-a-matic adapters to both Pentax K and Nikon F (Pre-Ai) available. These adapters allow you to mount a tamron Adaptall lens as if it was a manual focus in manual exposure mode.
If your dSLR is a Canon EF or Sony/Minolta A and Four thirds camera, you can mount an adapt-a-matic lens with an M42 adapter ring if you get an aftermarket dumb adapter.
If you intend to adapt your Tamron Adaptall lens to a mirrorless camera
If you already have a number of adapters from the typical SLR mounts to your mirrorless camera (e.g. Canon FD / M42 / Nikon F / Olympus OM / Pentax K …) your best choice is to get an original Tamron adapter from adapt-a-matic to whatever your most favoured SLR era lens mount is.
If you intend to adapt your Tamron Adapt-a-matic lens to a film SLR
Given that the original purpose of the Tamron Adapt-a-matic mount was to allow the use of the same lens on several SLR systems, there are Adapt-a-matic adapters available for many film SLR systems, including1: Canon FD, Exakta, Konica AR, M42, Minolta SR, Miranda, Nikon F, Olympus OM, Pentax K, Petri FT.
Footnotes
- This list will only contain adapters that we at JAPB have witnessed. ↩︎