This is my quick review about the Viltrox AF 28mm f/4.5 for L-mount full frame lens with autofocus. It has been about a year since Viltrox announced that they would join the L-mount alliance. Joining brands like Leica, Panasonic and Sigma to produce officially licenced L-mount lenses with auto focus. And after that announcement in 2025 Viltrox was a little quiet. Since introducing the very nice AF 16mm f/1.8 for L-mount Viltrox haven’t added any new L-mount lenses. Until now! With the introduction of the Viltrox AF 28mm f/4.5 for L-mount they add a lens that will certainly attract the attention of L-mount users. I’ve written a full review about this lens in Z-mount earlier, you can read that full review here. But I’ll try to summarise my experience here and tell you more about the experience with it as an officially licenced lens on L-mount. For this review I’ve used the lens on the Panasonic S5d.
Viltrox and the L-mount alliance
L-mount was initially developed by Leica. Leica understood that to have a chance against the big three they needed more products to use their mount so users would have more options. Therefor they opened the L-mount by forming the L-mount alliance with Panasonic and Sigma in 2018. And in 2025 Viltrox also joined. Joining the alliance means a brand can make officially licenced products for L-mount. This may not mean a lot to you, but it is a seal of approval and warranty that your lens will work as intended on all official L-mount cameras. And, more importantly that it will keep working, even with new firmware updates and on future camera models.
Before, the options for L-mount users were limited to mostly Leica, Panasonic and Sigma AF-capable lenses. With Viltrox joining it will mean that most of the great Viltrox lenses will eventually also be available for L-mount. Viltrox is understandably proud they are part of the alliance and show this by adding the official L-mount logo on their L-mount lenses and boxes.
The Viltrox AF 28mm f/2.8
As you can read in my original review of this lens, it has a lot going for itself:
- Incredible low price – 109 EUR/ 99 USD
- Full frame compatible
- Almost as small as a body-cap
- Weighs about 60 grams
- Full AF functionality on L-mount
- Fixed f/4.5 aperture
- Incredible sharpness for a lens this affordable
- USB-C port for updates
- Full metal mount
- Built-in lens hood
For the price this is already almost too good to be true, but of course it also has some downsides:
- Fixed aperture, so it is always at f/4.5
- Strong vignetting
- Limited flare resistance when shooting against a strong light source
How does it work on L-mount
In one word: perfect! As with the Z-mount version you will have full AF functionality on your L-mount camera with the Viltrox AF 28mm f/4.5 L-mount. This means tracking and face- and eye detection work just as good as with any Panasonic, Leica or Sigma lens. Focus is fast and reliable and I never had any hiccups or problems with this lens on the Panasonic S5.
On the Z-mount version I noticed AF was a little slower around the minimum focusing distance in low light. That is the same here. It will lock-on but it is just a little slower and will occasionally miss. I think this is caused by the slower maximum aperture letting in less light for the AF-system to work with. Still, it is very usable in all-round use. This means that this lens is also perfect for street photography.
Is the Viltrox AF 28mm f/4.5 the right lens for your L-mount camera?
I said it before in my full review for the Z-mount version and it is also true for the L-mount version. For this price you can’t go wrong with this lens. It is much sharper and functional than I had ever dreamed it could be for something so small and affordable. And it is a lot of fun to use. Because of the small size your full frame camera will feel almost like a point and shoot.
It will work on any L-mount camera, but they are the perfect match for the Panasonic S9 and Sigma BF. Those camera’s will actually fit in you pocket when you mount this tiny lens. It competes with the Panasonic 26mm f/8 when it comes to size, but this has a f/4.5 aperture and autofocus that the Panasonic misses. So this is a way more interesting option in my opinion. And it is about half the price!
For me the small size en low weight means I will bring my camera along more. And when I’m packing my bag there is no reason not to throw this little lens in there as well. It takes up virtually no space weighs next to nothing. And the results are very good, much better than expected. And the official L-mount support is the cherry on this little cake.
So if you are still undecided: just go for it. You will be very happy with this little wonder for your L-mount camera.
