SG-image MF 50mm F1.8 Shaped Aperture

Focal length: 50 mm
Aperture: f/1.8
Weight: 311 g
Filter diameter: 58 mm
Min. focus distance: 50 cm
Length: 48 mm

Overview

The SG-image MF 50mm F1.8 Full Frame Lens with Shaped Aperture is a manual focus standard prime with a creative twist. Instead of a classic iris it uses a variable shaped aperture, so that out-of-focus highlights take on shapes such as hearts, stars or diamonds. SG-image offers it for Sony E, Fujifilm X, Nikon Z, Micro Four Thirds, Canon EF-M, Canon RF and Leica L mounts. It is designed to cover a full frame sensor and is aimed at expressive portraits and artistic shots.

Optical design

According to SG-image the lens has 7 elements in 5 groups and a 44 degree angle of view, with a maximum magnification of 1:7.7. The spec sheet lists the aperture as a variable shape aperture with one blade and a fixed aperture ring, and it gives no minimum aperture and no special glass types. The maximum opening is f/1.8.

Focusing and handling

Focusing is manual. The minimum focus distance is 0.5 m. SG-image says that when the shaped aperture lens is stopped down, out-of-focus highlights and light sources take on the specific shape, and that the lens still works as a regular standard prime. Press reports mention interchangeable aperture plates, but the product page does not describe how the shapes are changed in practice.

Build and size

The barrel is metal. The lens measures 69 mm in diameter and 48 mm in length, weighs about 311 g and takes 58 mm filters. The specification is the same for all seven mounts. Because it covers full frame, it also works on APS-C and Micro Four Thirds bodies, where the field of view is narrower.

Where it fits

Creative bokeh lenses are a niche. The Lensbaby Velvet 85mm f/1.8 in the database is another effect-oriented prime for similar mounts. For a conventional 50mm option with autofocus, SG-image's own AF 55mm F1.8 or the 7Artisans AF 50mm F1.8 (Sony E, Nikon Z) are alternatives.

Pros and cons

Pros

Shaped bokeh as a distinctive creative effect
Full frame coverage with F1.8 aperture
Metal construction, 58 mm filter thread
Minimum focus distance of 0.5 m
Seven mounts supported

Cons

Manual focus only
Unusual aperture design with one blade and no conventional stop-down range published
Special effect is not useful for every kind of shot
No minimum aperture or glass details published
No weather sealing mentioned

Verdict

This SG-image lens is a creative tool first and a standard prime second. It makes sense for portrait and still life photographers who enjoy playing with bokeh shapes, and its price class is low according to the maker. Anyone looking for a neutral, general purpose 50mm should pick a conventional lens instead.

Technical Specifications

min focal length: 50 mm
max focal length: 50 mm
max f (min zoom): f/1.8
max f (max zoom): f/1.8
min. aperture: –
Elements: 7
Groups: 5
Weight: 311 g (0.69 lb)
Filter diameter: 58 mm
min focus distance: 50 cm (19.69 in)
Length: 48 mm (1.89 in)
Diameter: 69 mm (2.72 in)

Simulate depth of field and angle of view

Which cameras does the SG-image MF 50mm F1.8 Shaped Aperture fit?

The SG-image MF 50mm F1.8 Shaped Aperture fits all Micro Four Thirds cameras. There its field of view equals 100 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)