Samyang 8mm f/2.8 ED AS IF UMC Fisheye Lens Review

Samyang 8mm f/2.8 ED AS IF UMC Fisheye Performance

As is often true of the performance of fisheye lenses, sharpness in the centre of the frame is very high from maximum aperture. In fact this lens delivers outstanding sharpness in the centre of the frame between f/2.8 and f/8. Clarity towards the edges of the frame is good at f/2.8, but rises to excellent levels as the lens is stopped down to between f/5.6 and f/8.

How to read our charts The blue column represents readings from the centre of the picture frame at the various apertures and the green is from the edges. Averaging them out gives the red weighted column. The scale on the left side is an indication of actual image resolution. The taller the column, the better the lens performance. Simple. For this review, the lens was tested on a Sony NEX-3 using Imatest.

The achilles heel of fisheye lenses is often the level of chromatic fringing produced along high contrast edges towards the edges of the frame. Although this lens displays quite high levels of CA towards the edges, with fringing approaching 1.5 pixel widths at f/2.8 and f/22, this is still a reasonable level, as many fisheye optics display much higher levels of fringing. Still it may pay to be aware of this, especially if you intend to produce very large prints.

How to read our charts Chromatic aberration is the lens' inability to focus on the sensor or film all colours of visible light at the same point. Severe chromatic aberration gives a noticeable fringing or a halo effect around sharp edges within the picture. It can be cured in software. Apochromatic lenses have special lens elements (aspheric, extra-low dispersion etc) to minimize the problem, hence they usually cost more. For this review, the lens was tested on a Sony NEX-3 using Imatest.

Distortion is typical of a fisheye lens with straight lines near the edges of the frame curving wildly. However, this lens produces images with stereographic projection, which results in more natural looking images than typically found with fisheye lenses that produce images with equal-area projection. Objects placed near the edges of the frame appear far less compressed than those taken with a lens that produces equal-area or orthographic projection.

Due to the extreme angle of view, formal testing of how illumination falls off towards the corners isn't possible. In use, at f/2.8 and f/4 a slight, but gradual falloff in brightness can be seen appearing towards the corners, but this appears visually even by f/5.6

Flare and loss of contrast when shooting with bright light sources in the frame are both well controlled. A little flare and loss of contrast may be seen with a bright source of light in the frame when shooting at wide apertures, but this is reduced as the lens is stopped down.

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