SG-image AF 25mm F1.8 MFT

Focal length: 25 mm
Aperture: f/1.8
Weight: 133 g
Filter diameter: 52 mm
Min. focus distance: –
Length: 30 mm

Overview

The SG-image AF 25mm F1.8 MFT is an autofocus standard prime for Micro Four Thirds cameras from Panasonic Lumix, Olympus and OM System. SG-image presents it as an everyday carry lens with a metal body and a bright F1.8 aperture. On Micro Four Thirds the 25mm focal length gives about 50mm in full frame terms, a classic normal view. A metal square lens hood is included, according to SG-image.

Optical design

SG-image gives the construction as 7 elements in 5 groups, including 3 high refractive index elements that it says help suppress chromatic aberration and edge distortion. The 9-blade diaphragm covers F1.8 to F16 according to the manufacturer's Amazon listing, which also lists an angle of view of 39.6 degrees. The minimum focus distance and magnification are not stated on the sources reviewed here. The sharpness claims on the product page are marketing statements and have not been checked.

Autofocus and handling

Focusing is by a built-in STM stepping motor, which SG-image describes as quiet and suited to video. The page says the lens supports eye detection autofocus on bodies that offer it, and the barrel has a textured focus ring for manual override.

Build and size

The lens has an all-metal barrel and mount. It weighs about 133 g and is 30 mm deep, according to SG-image. The filter thread is 52 mm per the manufacturer's Amazon listing. The diameter is not stated in the sources reviewed.

Where it fits

On Micro Four Thirds the Olympus M.Zuiko Digital 25mm F1.8 is the best known native option, and in the database the Olympus M.Zuiko Digital ED 25mm F1.2 Pro and the Panasonic Leica Summilux DG 25mm F1.4 sit in higher classes. Among budget options, the 7artisans 25mm F1.8 is a manual alternative. SG-image's APS-C AF 25mm F1.8 for Sony E, Fujifilm X and Nikon Z is the sibling with similar optics.

Pros and cons

Pros

Light at about 133 g and only 30 mm deep
Autofocus with F1.8 aperture
Metal barrel and mount
9-blade diaphragm and 52 mm filter thread
Hood included

Cons

No image stabilization in the lens
No aperture ring
Minimum focus distance and diameter are not published
No weather sealing mentioned
New model with little independent test data

Verdict

The SG-image AF 25mm F1.8 MFT is a small, light autofocus normal lens for Micro Four Thirds. It suits photographers who want a compact prime with a metal build and a lens hood in the box, while those who need published close-focus data or weather sealing should look at the established Olympus and Panasonic lenses.

Technical Specifications

min focal length: 25 mm
max focal length: 25 mm
max f (min zoom): f/1.8
max f (max zoom): f/1.8
min. aperture: f/16
Elements: 7
Groups: 5
Weight: 133 g (0.29 lb)
Filter diameter: 52 mm
min focus distance: –
Length: 30 mm (1.18 in)
Diameter: –

Simulate depth of field and angle of view

Which cameras does the SG-image AF 25mm F1.8 MFT fit?

The SG-image AF 25mm F1.8 MFT fits all Micro Four Thirds cameras. There its field of view equals 50 mm in full-frame terms (crop factor 2).

Micro Four Thirds cameras

Micro Four Thirds:: OM System PEN, OM System OM-3, OM System OM-5 Mark II, Panasonic Lumix G97 (G99M2), Panasonic Lumix GH7, OM System OM-1 Mark II, Panasonic Lumix G9 II, Panasonic Lumix G100D, OM System OM-5, OM System OM-1, Panasonic Lumix GH6, Panasonic Lumix GH5 II, Olympus PEN E-P7, Olympus OM-D E-M10 Mark IV, Olympus OM-D E-M1 Mark III, Panasonic Lumix G100 (G110), Panasonic Lumix BGH1, Olympus PEN E-PL10, Olympus OM-D E-M5 Mark III, Panasonic Lumix G95 (G90, G91), Olympus OM-D E-M1X, Panasonic Lumix GX9, Panasonic Lumix GF10 (GF90, GX880), Olympus PEN E-PL9, Panasonic Lumix GH5S, Blackmagic Pocket Cinema Camera 4K, Panasonic Lumix G9, Olympus OM-D E-M10 Mark III, Panasonic Lumix GF9 (GX850, GX800), Panasonic Lumix GH5, Olympus PEN E-PL8, Olympus OM-D E-M1 Mark II, Panasonic Lumix G85 (G80, G81), Panasonic Lumix GX85 (GX80, GX7 Mark II), Olympus PEN-F, Olympus OM-D E-M10 Mark II, Panasonic Lumix GX8, Panasonic Lumix G7, Panasonic Lumix GF7, Olympus OM-D E-M5 Mark II, Panasonic Lumix GM5, Olympus PEN E-PL7, Panasonic Lumix GH4, Olympus OM-D E-M10, Panasonic Lumix GM1, Olympus OM-D E-M1, Panasonic Lumix GX7, Olympus PEN E-PL6, Olympus PEN E-P5, Panasonic Lumix G6, Panasonic Lumix GF6, Blackmagic Pocket Cinema Camera, Olympus PEN E-PM2, Olympus PEN E-PL5, Panasonic Lumix GH3, Panasonic Lumix G5, Panasonic Lumix GF5, Olympus OM-D E-M5, Blackmagic Cinema Camera (MFT)