(P)REVIEW: NISI F4 15MM

The NiSi F4 15mm is the first lens from this brand. It takes courage to release a super-wide angle right out of the gate.

NiSi is a brand that has become known for square filters of high quality. More recently, the brand has also started making round screw filters, and they also offer a high-quality macro filter: the NiSi Close Up Lens Kit. So they know about optical products. Now they are expanding the range with a lens, a 15mm super-wide angle for full-frame mirrorless cameras from Sony, Canon, Nikon and the APS-C models from Fuji. On full frame, the NiSi F4 15mm offers a field of view of 112 degrees and on APS-C, 78 degrees. The lens has no electronic coupling and a manually operated aperture. It thus bears similarities to, for example, the recently introduced Laowa 14mm FF RL Zero-D. What is also a similarity between the NiSi and the Laowa is that both have a filter thread to permit the use of ordinary screw filters. The brightness of both is equal to F4, but the NiSi has a larger diameter and a larger filter size of 72mm, where the Laowa is slimmer and has a filter size of 52mm. We’re curious whether the larger diameter of the NiSi also makes a difference for the image quality.

The optical design is fully tailored to mirrorless cameras. There is and will be no version for SLR cameras. NiSi has used two ED lens elements and a double aspherical element for the optical design. This should strongly combat chromatic aberration. Furthermore, NiSi also claims that the lens has little distortion and is therefore suitable for architectural applications. Of course, we will be happy to test this in practice.

BUILD

The NiSi F4 15mm is a fully mechanical lens that, in an almost old-fashioned way, has an all-metal housing. It has a reasonably wide, ribbed focusing ring at the front with an engraved distance scale in feet and meters and a depth of field scale on the silver-colored, non-rotating ring just behind it. Further to the rear is the aperture ring that runs from F4 to F22. The lens is 8 centimeters long, not very big but not really small, and the same applies to the weight of 470 grams.

The optical design consists of 12 lens elements in 10 groups. Two of those elements are made of ED glass, and one element is doubly aspherical. The aperture consists of 10 blades and, according to NiSi, already gives “sun stars” from full aperture. That has the advantage that you don’t have to stop down to get beautiful stars around point-shaped light sources. The filter size is 72mm. This allows screw filters to be used as well as NiSi’s square 100mm filters with the NiSi filter holder.

FOCUSING

The NiSi has a long, smooth and, of course, completely linear focus thanks to its mechanical operation. On the focusing ring, the set distance can be read in meters and feet, from the shortest setting distance of 20 centimeters to infinity. The depth of field can be read on the depth of field scale. This makes it easy to set the hyperfocal distance or zone setting, for example, at least if the focus ring is well calibrated.

IMAGE QUALITY

The MTF curves of the NiSi F4 15mm look good. The sharpness already looks high at full aperture with a small gradient to the corners, and those improve with stopping down two stops. However, MTF curves are calculated in the computer for almost all brands. In practice, differences can arise. We hope to have a copy in our test lab soon and will then publish a full review with our experiences in practice.

ConclusiON: REVIEW NiSi F4/15mm