Cameras Ranked

20 Tamron 20mm F2.8 Di III OSD M1:2

The Tamron 20mm F2.8 Di III OSD M1:2 is a prime lens for Sony E-mount (Full frame) that covers 20 mm at f/2.8, weighs 220 g and focuses as close as 0.11 m. Next to 10 other full frame Sony E-mount prime lenses in its focal range, it suits you if you carry it all day or travel light, or you want a wider view at the short end. If you shoot in low light or want a blurrier background, every other one that does better on brightness gives up weight. If you want more reach at the long end, every other one that does better on reach gives up width.

  • f/2.8widest aperture
  • 220 gweight
  • 51bodies it fits
To one scale. Tamron 20mm F2.8 Di III OSD M1:2: length 64 mm, diameter 73 mm, filter thread 67 mm.64 mmø73
To scale from the maker's length and diameter, the mount on the left and the filter thread in yellow at the front. The rings are drawn, not measured.

Compare it with another lensAll Sony E-mount lenses

To one scale. Tamron 20mm F2.8 Di III OSD M1:2: length 64 mm, diameter 73 mm, filter thread 67 mm.64 mmø73
To scale from the maker's length and diameter, the mount on the left and the filter thread in yellow at the front. The rings are drawn, not measured.

Where it sits

11 lenses

Full frame Sony E-mount prime lenses in its focal range that state each value, this one included. Each tick is one; the thick one is this one.

Bodies it fits

51 bodies

All cameras, by maker and mount

Specifications

Focal length
20 mm1
Widest aperture
f/2.81
Closest focus
0.11 m2
Maximum magnification
0.5x2
Stabilization
No
Mount
Sony E-mount2
Covers
Full frame
Type
Prime
Weight
220 g2
Length
64 mm2
Diameter
73 mm2
Filter thread
67 mm2
On sale from
Jan 30, 20202
Elements
102
Groups
92
Aperture blades
72
Hood
Flower-shaped hood2

Sources

  1. Wikidata, checked Oct 9, 2026 (CC0 1.0)
  2. Tamron product specifications, checked Oct 6, 2026

Worked out by code, not stated by a source

  • Read from the lens name: each maker marks the sensor size a lens covers (Sony FE/E, Canon RF/RF-S, Nikon DX, Tamron Di III/Di III-A, Sigma DG/DC); every Fujifilm X lens is APS-C and every Micro Four Thirds lens is Four Thirds.
  • Read from the lens name: Sony marks optically stabilized lenses OSS, Canon IS, Nikon VR, Fujifilm OIS, Panasonic O.I.S., Tamron VC and Sigma OS; a lens from these makers without the mark has no optical stabilization.
  • Prime or zoom, read from the focal length in the lens name.

Each value is checked automatically against the source it links, on the date shown. How we build these pages

† The makers' own tables, row by row, with labels in our plain words (translated where the maker's page isn't in English); each row's numbers are checked against the page it links.

Full specifications†

Show all 11 rows
Full specificationsTamron 20mm F2.8 Di III OSD M1:22
Diagonal angle of view94°30' (for full-frame mirrorless format)
Optical element arrangement10 elements in 9 groups
Closest focusing distance0.11m (4.3 in)
Highest magnification ratio1:2
Filter thread diameterΦ67mm
Maximum lens diameterΦ73mm
Lens length64mm (2.5 in)
Lens weight220g (7.8 oz)
Number of aperture blades7 (circular diaphragm)
Smallest aperture settingF22
Compatible camera mountSONY E Mount

How the pick works

  1. Widest aperture3

    Lower wins once they are 0.3 apart.

  2. Weight2

    Lower wins from a 12% gap.

  3. Focal length (longest)2

    Higher wins from a 15% gap.

  4. Focal length (widest)2

    Lower wins once they are 2 mm apart.

  5. Optical stabilization1

    Having it wins.

  6. Closest focus, wide end1

    Lower wins from a 15% gap. Compared only between lenses of the same focal length (widest).

  7. Filter thread0.5

    Lower wins once they are 5 mm apart.

  8. Lead for a pick1

Our pick or our take adds up the importance of each real difference, with these importances and thresholds: a gap smaller than its row's threshold is too close to call and counts as the same. They are our editorial choice, not a measurement, the same on every page, and they never read prices, sales or who sells it.

Paid placements0

How we rank, in full