Note: I have now given this lens review it's own page on the main site here.
I got the Sigma 135mm f/1.8 Art lens in 2017. Although its stunning clarity made it great for bokeh pano and squirrel photography, its 1,933g (4.26 lbs) weight on the Sony A9 meant it often didn't get taken out. A few years later I upgraded to the Sony 135GM lens, which took the weight down to a more manageable 1,623g (3.58 lbs). However, in 2022 Samyang brought out a version that would drop the weight (with the A1) down to 1,509g (3.32 lbs). At less than half the price of the Sony 135GM; Could this lens actually be any good?...
After reading some glowing reviews (about the Samyang), I was very tempted to try it. When I saw one come up for sale I just couldn't resist it any longer. Over the last couple of days I have been putting it through its paces and I have to say that I am very impressed. I have already noticed the weight advantage, but wow - the image quality too...
If you're not familiar with fast 135mm lenses and why they're so special, let me explain... It's all about entrance pupil (that's how big the lenses aperture looks through the front elements when wide open) and the bigger the better. They're great in low-light, but they also allow impressive subject isolation (shallow depth of field / background blur).
The entrance pupil on this lens is a whopping 75mm! That's as big as they get before the weight, cost and focal lengths skyrocket. The glass is over three times the surface area of a 50mm f/1.2 lens (letting in over three times the amount of light). The Samyang weighing only 772g (1.7 lbs) is crazy! It's actually lighter (and cheaper) than some 85mm f/1.4 lenses, which only have 61mm entrance pupils and won't reach this level of image quality.
Holding up the camera and lens to shoot 40-120 images without a tripod really does make you appreciate the lower weight. By the end of the day I had noticeably less shoulder strain from the camera bag too.
Using this lens on the Sony A1 will make its AF perform better than on lower Sony cameras. It's not the lightest mirrorless camera, but it is the lightest high resolution stacked sensor one.
I really like stacked sensor mirrorless cameras for shooting wildlife and bokeh panos, but if you're willing to drop that requirement you can actually get the total weight down to 1,281g (2.82 lbs) with the Sony A7C. That is an absolutely crazy-low weight for what you get! Also the combo would cost a mere £1600 second hand. The more feature packed A7CR would set you back quite a bit more, but is only another 6g (0.375 oz)!
After reviewing the first few photos taken with the Samyang, it was clear that the image quality is right up there with the Sony 135GM. Many reviewers had been reporting this, I just couldn't quite believe it given the price tag and weight, so...
What's the catch?...
Well, there are a couple areas where the Samyang doesn't quite keep up with the Sony lens... Auto focus seems to not lock on to subjects, or track them quite as surely, although it's not far off (at least on the A1). It's worth noting that the Sony 135GM can't keep up with squirrels in motion either. Since it's a third-party lens the burst speed of the camera maxes out at 15fps (instead of 30fps for the A1). There is no aperture ring or AF switch, plus the custom button doesn't work by default. Weight savings diminish a little when you consider the Samyang hood and front cap are bigger and heavier than the Sony ones - 120g vs 105g (7.5 vs 6.5 oz). Since you'll need both of those, the actual weight savings over the Sony lens are actually closer to 165g (5.8 oz).
None of those things are deal-breakers for me however and certainly not for its price. I like the design and finish. The manual focus ring has a nice feel to it (focus by wire of course). It is weather sealed and the hood is nice too. I actually prefer these twist-click type hoods over the ones with buttons (Sony 135GM), since - for some reason - they're easier to screw on backwards for me. It is also a longer hood, which means it should be better at keeping out rain and sun (although I didn't have issues with the 135GM hood either).
The length, shape and size of these two lenses is very close. I initially wondered whether the Samyang might be a clone of Sony's optical design too, but diving through the specs online suggests this is not the case (see below).
Competition & Cameras
Auto focus 135mm f/1.8 lenses have not been around for very long. The first company to offer one was Zeiss (for the Sony Alpha DSLRs) back in 2007 and they had the market to themselves for a while. Sony's first full frame DSLR (A900) came out a year later (2008) and the combo weighed a hefty 1,950g (4.3 lbs). A decade later Sigma took up the mantle, making the lens for most DSLR mounts. The wide-open performance set new standards for lenses of this this size/type! Since then subsequent variants have been chasing absolute image quality perfection. Here are the weights for all the versions of this lens on mirrorless, thus including adaptors for DSLR versions, to be fair (weights do not include lens caps or hood):
2007 - Zeiss A - 1,210g (2.67 lbs)
2017 - Sigma - 1,200g (2.65 lbs)
2019 - Sony FE - 950g (2.09 lbs)
2022 - Samyang - 772g (1.7 lbs)
2023 - Canon RF - 935g (2.06 lbs)
2024 - Nikon Z - 995g (2.19 lbs)
Here are those with a few full frame cameras to show total weight:
The Canon R8 is an incredibly light full frame mirrorless camera. It's a low end body that doesn't have 'image stabilization' (IBIS), but amazingly the Canon RF 135mm f/1.8 lens does (IS). Making it an oddly balanced (budget wise), but fun little combo for only 1,396g (3.07 lbs)! Although Canon don't have a high-res stacked option, their R5 is close and that would weight 1,673g (3.69 lbs) with the lens, which is also pretty good.
The Nikon Z5 is their lightest full frame mirrorless camera. This low end body does have IBIS, but the Nikon Z 135mm f/1.8 lens being more than triple the price of the Samyang makes it feel like an odd choice here. Those two together weigh 1,670g (3.68 lbs), which is not great considering the body features. If we step up to Nikon's smallest pro camera (the Z8), the weight shoots up to 1,905g (4.2 lbs) - putting it firmly in DSLR territory. A whopping 398g (0.88 lbs) heavier than the Sony equivalent, but with worse battery life, ouch! Bloody good camera otherwise!
The basic Sony A7IV model with the 135GM lens weighs (1,609g / 3.55 lbs), which is not too heavy, but switching the lens to Samyang would take that down to (1,431g / 3.15 lbs). However that's not the lightest Sony body. The the A7C (or A7CII) would take the weight down further, to (1,287g / 2.84 lbs) and the ZV-E1 would shave a little more off still (1,255g / 2.77 lbs). Those are all full frame cameras with IBIS too.
Unfortunately for other mirrorless platforms the Samsung AF 135mm f/1.8 lens is currently only made in the Sony FE mount. This may change though and Viltrox may soon get a similar option, so if you're on Canon or Nikon keep your fingers crossed...
Cost
Sensor resolution and dynamic range has largely stagnated over the past 10-15 years, but camera / lens speed and weight improvements have really impressed me over the past 5-10, especially with Sony, Sigma and Samyang! The latter two especially so with great value. Although the image quality performance is very similar between all the new 135mm f/1.8 lenses mentioned here (not the "old" Zeiss), their cost can differ massively (prices below from WEX Photo):
Being able to buy FOUR Samyang lenses for the price of ONE Nikon version is just obscure, so think about this... For the price either the Nikon or Canon version you can get the Samyang lens and a Sony A7C II camera (new). Combining a 33mp sensor, 7 stops of IBIS, AI subject recognition and a razor sharp lens with stunning subject isolation!