AstrHori 6mm f/2.8 Circular Fisheye

Focal length: 6 mm
Aperture: f/2.8
Weight: 340 g
Filter diameter: –
Min. focus distance: 8 cm
Length: 61 mm

Overview

The AstrHori 6mm f/2.8 Circular Fisheye is a manual-focus circular fisheye for full-frame mirrorless cameras, offered for Sony E, Leica L, Canon RF and Nikon Z. Instead of filling the rectangular frame, it records a circular image with a 220 degree angle of view, which covers more than a hemisphere. AstrHori recommends it for urban scenes, astrophotography, street and portrait experiments, landscapes and video.

Optical design

The lens has 10 elements in eight groups. The eight-blade aperture runs from f/2.8 to f/16, and the angle of view is 220 degrees. The minimum focusing distance is only 0.08 m, which AstrHori presents as a way to combine strong edge distortion with subjects placed very close to the lens, similar to wide-angle macro shots.

Focusing and handling

Focusing is manual. The barrel carries a focus ring, an aperture ring with click stops and a depth-of-field indicator. There is no autofocus and no stabilizer. According to AstrHori, f/2.8 combined with the 220 degree view can capture the night sky and the Milky Way in one frame without stitching, and a central position of the pole star gives concentric star trails.

Build and size

The finish is matte black. In its Sony E version the lens measures 64.8 mm in diameter and 61 mm in length, and it weighs about 340 g.

Where it fits

In this database, the Sigma 8mm F3.5 EX DG Circular Fisheye and the Sigma 4.5mm F2.8 EX DC HSM Circular Fisheye are circular fisheyes for Canon EF and Nikon F. For full-frame mirrorless fisheyes with a full rectangular frame there are the AstrHori 12mm f/2.8 Fisheye, the Venus Laowa 4mm F2.8 Fisheye and the 7artisans Photoelectric 10mm f/2.8 Fisheye. The AstrHori 6.5mm f/2 Fisheye is an APS-C counterpart from the same maker.

Pros and cons

Pros

220 degree angle of view on full frame
Minimum focusing distance of 0.08 m
f/2.8 maximum aperture for night work
Aperture ring with clicks and a depth-of-field indicator

Cons

Circular image means large unused areas of the sensor
Extreme distortion by design
Manual focus and manual aperture only

Verdict

The AstrHori 6mm f/2.8 Circular Fisheye is a specialist lens for creative full-frame photographers and video makers who want the circular look. It offers an extreme view and very close focus, while everyday use is limited by the circular format.

Technical Specifications

Min. focal length: 6 mm
Max. focal length: 6 mm
Max. aperture (min. zoom): f/2.8
Max. aperture (max. zoom): f/2.8
Min. aperture: f/16
Elements: 10
Groups: 8
Weight: 340 g (0.75 lb)
Filter diameter: –
Min. focus distance: 8 cm (3.15 in)
Length: 61 mm (2.4 in)
Diameter: 64.8 mm (2.55 in)

Manufacturer data: astrhori.cn

Simulate depth of field and angle of view

Which cameras does the AstrHori 6mm f/2.8 Circular Fisheye fit?

The AstrHori 6mm f/2.8 Circular Fisheye is a full-frame lens for Sony E-Mount cameras. On full-frame bodies it uses the whole sensor; on APS-C Sony E-Mount cameras its field of view equals 9 mm in full-frame terms.

Sony E-Mount cameras

Full frame:: Sony A7R VI, Sony A7 V, Sony FX2, Sony A1 II, Sony A9 III, Sony A7C II, Sony A7CR, Sony ZV-E1, Sony A7R V, Sony A7 IV, Sony A1, Sony FX3, Sony A7S III, Sony A7C, Sony FX6, Sony A7R IV, Sony A9 II, Sony FX9, Sony A7 III, Sony A7R III, Sony A9, Sony A7R II, Sony A7S II, Sony A7 II, Sony A7S, Sony A7, Sony A7R
APS-C:: Sony ZV-E10 II, Sony A6700, Sony FX30, Sony ZV-E10, Sony A6600, Sony A6100, Sony A6400, Sony A6500, Sony A6300, Sony A6000, Sony A5100, Sony A5000, Sony A3000, Sony NEX-5T, Sony NEX-3N, Sony NEX-6, Sony NEX-5R, Sony NEX-F3