Rokinon 75mm F1.8 AF Sony E (399) is a cheap lens that offers full frame coverage and portrait-friendly focal length. The lens's telephoto design is short and blurs backgrounds. It also supports the advanced autofocus capabilities of all Sony cameras. The lens' optics aren’t the best, but they can be used for weather protection. It's worthwhile to invest $200 extra and get the Sony FE85mm F1.8.
Related Reading: Fujifilm XQ2 Review
The Budget Price and the Build
Rokinon uses metal lenses all the time, although it has chosen to use plastic barrels in many of its products for the Sony mirrorless camera system. With a weight of 8.1 ounces the 75mm F1.8 lens, it is among its lightest lenses. This lightweight plastic design allows for an even lighter lens. The lens measures 2.7x2.6 inches (HD) and can accommodate 58mm filters.
The lens is also sold under the Samyang banner. Aside from branding, there are no differences between Rokinon and Samyang versions.
The angle of the view is slightly wider than 85mm lenses, which are the most common focal lengths for portrait photographers. The f/1.8 lens is narrower than Rokinon’s 85mm F1.4 Sony Autofocus (3.9 by 3.25 inches, 1.3 lbs).
Still, it's a good fit for portraits and for other shots where you want to blur the background behind a subject. I tested it on a full-frame camera, but it will work with APS-C models as well. It's sized well for the a6100 and a6400, and while its angle of view is narrowed when paired with a smaller sensor, you won't mind for portrait work.
You will need to be extra careful when taking outdoor photos. There is no splash or dust protection. Rokinon includes a protective zippered case and a lens cover that can be reversible. Stabilization is also omitted—it's a feature built into almost every full-frame model from Sony, but is only included in a couple of APS-C models, the a6500 and a6600.
Autofocus is quick and quiet, and all of the expected Sony features are supported, including eye detection and Real-Time Tracking. The STM motor takes a beat to drive from the minimum focus distance to infinity, but is generally quick and quiet. The angle of view does change visibly when adjusting focus, making the 75mm a less than ideal choice for video shots.
Two functions can be performed by the control ring. It's the manual-focus ring in Mode 1. For a pleasant manual focus experience, it turns smooth but has some resistance. You can use in-camera tools, such as frame magnification to get the subject exactly sharp.
Flipping the toggle switch to its Mode 2 setting changes the function of the ring. Out of the box it sets the f-stop, but Rokinon plans on extending its functionality via future firmware updates. A $60 accessory, the Rokinon Lens Station, is available; in addition to loading firmware, the Lens Station makes it possible to fine-tune autofocus response.
You can focus as close to 27.2 inches (69 cm) so make sure you have some space between the subject and your camera. It's a fine working range for portraiture—we substituted some statues for live models for the purposes of this review.
Don't reach to the lens for macro work, though—with just 1:7.7 magnification, you can't get in for the really close details. The dandelion, above, was captured at the minimum working distance with a full-frame camera.
Related Reading: Pentax SMC FA 43mm f/1.9 Limited Review
Not for a7R Models
I also tested the F1.8 AF 75mm along with 60MP a7R IV software and Imatest. The lab results were disappointing. The combination produces just-okay 3 070 lines in the frame at f/1.8. It's mitigated by stronger center performance, a very good result (4,100 lines)—if you frame your subject toward the center, bokeh will hide many imperfections.
Center resolution holds steady at f/2 and f/2.8, but the average ticks up slightly due to improved contrast away from the center of the frame. The average enters good territory at f/4 (3,575 lines), and it crosses into the very good range at f/5.6 (3,910 lines).
However, it doesn't get any better. At f/8 the peak is still within the excellent range of 4,200 lines. This is disappointing as it's not common to see outstanding or excellent resolution with short-telephoto prime lenses. Rokinon's 85mm F1.4 Sony FAF captures sharper details at f/1.4 that the 75mm F1.8.
There are other areas that hold up better. Distortion is well controlled, and there's barely any vignetting, even if you opt to disable in-camera correction. Chromatic aberration is all but absent. I wasn't able to induce any sort of purple fringing around tree branches. I did note a very slight bit of false green in bokeh; it took a close look to find it, and Lightroom removed it with a one-click correction.
Even without critical sharpness, images look quite good resized for the web—the a7R IV is overkill for Instagram. These drawbacks become more obvious when you view images on large, high-resolution displays or make prints.
The Sony is not for you if...
Although it isn't the sharpest, I do like the Rokinon75mm F1.8. This lens is one of the most affordable of its kind, making it attractive to those photographers who might want to occasionally use this type of lens. You don't need to worry about it being too small to fit in your bag. It's also more likely that the camera will end up with owners of 24-megapixel models like the A7 II or A7 III where the drawbacks of the product are much less obvious.
I'd more strongly recommend the lens if the Sony FE 85mm F1.8 wasn't such a good value. It's a bit pricier, at $600, but it brings better optics to the table, along with the dust and splash protection Sony system owners expect. This is one time where it's worth it to go for the name brand.