Samyang AF 75mm f/1.8 - Full Frame Featherweight
Samsung have been a bit lacklustre in the past, but more recently they have come out with some real gems lately and this was the first lens that they made where I really took notice. The 75mm f/1.8 is a very small and light lens for what it is. The first of it's kind, it has spawned a slew of other 75mm leneses from Viltrox and Sirui. You'd be forgiven for thinking that this one was APS-C only given it's size and price, but it's actually just as good on full frame as it is on crop.
Sony A5100 | Ducati | 41 image Bokeh Pano
Size & Weight
Shown here on the Sony A5100, the Samyang 75mm might look rather large, but this is a miniscule camera that weighs a ridiculously light 494g (lens, camera, battery and memory card). This combo feels like a toy, but the image quality is surprisingly capable. This is equivalent to a 113mm f/2.7 on full frame, which is still pretty interesting. It is pretty useful for the friendly wildlife images that I usually shoot on a full frame 135mm f/1.8, which as you can see is much bigger and triple the weight.
Lens Entrance Pupils & Weights Compared
With the ultra low weight of the A5100 body here it makes the entrance pupil per kilogram ratio (84:1). One of the highest ratios I have ever seen on that camera (until the Sirui AF 75mm f/1.2 scored 88:1). If you swap out the camera for the Sony NEX C3 it will bump the score a further 8 points (92:1), but that camera will be noticeably more of a struggle to use, especially for bokeh panos (which is why I made this ratio score). With basic focus tracking, the A5100 is actually a pretty decent enough AF experience for friendly animals.
Sony A5100 | Red Squirrel | f/1.8, ISO 1000
Build & Design
The Samyang 75mm feels very plasticy, but that's not only necessary to achieve its weight, but fortunately quite nicely balanced with its size. Unfortunately this extreme weight and/or cost saving has manifested in a lack of weather sealing. I can understand it, but I would have liked at least a rubber ring on the lens mount. Surprisingly, the does have a custom switch, which controls what functions you can map to the focus ring. This is a nice way to add functionality to the only dial on the lens itself.
Sony A1 | Vole | f/2.0, ISO 800
Image Quality
I'm really impressive by the Sharpness of this lens. For something so small, light and fast that is quite shocking. Even when wide open and right down to the minimum focus distance (69cm) sharpness remains high and no haziness creeps in. Chromatic aberration is pretty well controlled and Longitudinal CA is not bad either.
Sony A5100 | Woodpcker | f/1.8, ISO 6400
Auto Focus
The focus speed of the lens is very good. Advanced features like eye-AF work perfectly well on all my Sony's and it's quiet too. The focus ring feels decently smooth and the focus by wire works pretty well.
Sony A1 | Vole | f/2.0, ISO 2500
Final Words
75mm lenses didn't really exist before this, but now we have a few. I really like them for APS-C sensors, where they are equivalent to a 113mm. For such a small and light lens the image quality is really impressive. It's a bargain for the price and that's before you take second hand prices into consideration. Sure it's a bit plasticy, but the build feels perfectly good enough for its weight.
Sony A1 | Red Squirrel | f/1.8, ISO 2000
Bokeh Panos
This technique (A-K.A. The Brenizer Method) involves stitching multiple images (with the same settings) to achieve a wider angle image with otherwise impossibly shallow depth of field and extreme sharpness. I used to be convinced that full frame cameras and lenses were the best way to maximize this effect even considering that they weigh more, but this lens has largely changed my mind.
I would recommend this 75mm f/1.8 as where lenses start to get interesting for bokeh panos. You can see it on the left of the box here (below). It's not the highest raw effect, but it scores extremely high on efficiency, only being beaten by the Sirui AF 75mm.
I really like the effective 113mm that you get here for bokeh panos. For a long time I have been hoping someone would make a full frame 105mm f/1.4, as it would have been a great sweet spot for effect, workflow and results (as long as it's not too heavy). This Samyang lens is not the biggest entrance pupil, but it is extremely easy to carry around and use.
