Sigma 28-70mm f/2.8 AF Specs, Equivalents & Depth of Field

28–70 mm

Focal length

f/2.8

Maximum aperture

75°–34°

Diagonal angle of view (Full frame)

Full frame

Designed for

2.5×

Zoom ratio

Specifications#

Brand: Sigma
Model: 28-70mm f/2.8 AF
Lens type: Standard zoom
Focal length: 28–70 mm
Maximum aperture: f/2.8
Image circle: Full frame (36×24 mm)
Mount(s): Sony / Minolta A-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 28 mm	At 44 mm	At 70 mm	Equiv. aperture (DoF)
Full frame	28 mm · 75°	44 mm · 52°	70 mm · 34°	f/2.8
APS-C	42 mm · 53°	66 mm · 36°	105 mm · 23°	f/4.2
APS-C (Canon)	45 mm · 51°	70 mm · 34°	112 mm · 22°	f/4.5
Micro Four Thirds	56 mm · 42°	88 mm · 28°	140 mm · 18°	f/5.6

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: 28 mm f/2.8 on full frame.

Focal	Aperture	at 1 m	at 2 m	at 5 m	at 10 m	Hyperfocal	Blur @2 m
28 mm	f/2.8	21.1 cm	88.5 cm	7.44 m	∞	9.36 m	0.4%
28 mm	f/4	30.4 cm	1.33 m	18.1 m	∞	6.56 m	0.3%
28 mm	f/8	65.3 cm	3.80 m	∞	∞	3.29 m	0.1%
44 mm	f/2.8	8.3 cm	34.2 cm	2.25 m	10.6 m	23.1 m	1.0%
44 mm	f/4	11.9 cm	49.2 cm	3.39 m	19.9 m	16.2 m	0.7%
44 mm	f/8	24.0 cm	1.03 m	9.87 m	∞	8.11 m	0.3%
70 mm	f/2.8	3.2 cm	13.2 cm	85.1 cm	3.51 m	58.4 m	2.5%
70 mm	f/4	4.6 cm	18.9 cm	1.23 m	5.17 m	40.9 m	1.8%
70 mm	f/8	9.1 cm	38.2 cm	2.56 m	12.7 m	20.5 m	0.9%

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 28 mm	NPF at 28 mm, f/2.8
Full frame	1/80 s	18 s	10 s
APS-C	1/100 s	12 s	8 s
APS-C (Canon)	1/125 s	11 s	7 s
Micro Four Thirds	1/125 s	9 s	7 s

Compatible cameras#

Bodies in our database with a native Sony / Minolta A-mount mount.

Adapt it to other systems#

Sony E-mount Canon RF Nikon Z Fujifilm X-mount Micro Four Thirds L-Mount Canon EF-M Fujifilm G-mount Hasselblad XCD Nikon 1 (CX)Pentax Q Samsung NX Canon EF Nikon F

Similar lenses#

Sony 28-75mm F2.8 SAM f/2.8
Tokina AF 28-80mm f/2.8 AT-X 280 Pro f/2.8
Sigma 24-105mm f/4.0 DG OS HSM [A] f/4
Sigma 24-60mm f/2.8 EX DG f/2.8
Sigma 24-70mm f/2.8 IF EX DG HSM f/2.8
Sony Zeiss Vario-Sonnar T* 24-70mm f/2.8 ZA SSM II f/2.8
Sigma 35–80mm f/4–5.6 DL-II AF f/4–5.6
Sigma 18-35mm f/1.8 DC HSM [A] f/1.8
Sony DT 18-55mm f/3.5-5.6 SAM f/3.5–5.6
Sony Minolta/Sony AF DT 18-70mm f/3.5-5.6 (D) f/3.5–5.6
Sigma 17-50mm f/2.8 EX DC OS HSM f/2.8
Tamron AF 17-50mm f/2.8 XR Di-II LD (Model A16) f/2.8

Frequently asked questions#

Is the Sigma 28-70mm f/2.8 AF full frame?

Yes — it covers the full 36 × 24 mm frame.

What is the Sigma 28-70mm f/2.8 AF equivalent to on APS-C?

On a 1.5× APS-C body it frames like 42–105 mm, and like 45–112 mm on Canon APS-C.

What is the Sigma 28-70mm f/2.8 AF good for?

As a standard zoom it suits everyday shooting, travel, events and walkaround use.

Sources & licences#

Lensfun lens database — CC BY-SA 3.0