This is my
third autofocus lens for the Sony a7c.
The Viltrox AF 28/4.5 (FE). It is a disputed lens, but I found it interesting.
The main attraction of this lens is its size. The lens is very small even for a pancake lens. However, it is an autofocus lens. Moreover, it is an autofocus only lens. There is no possibility of manual focus: no ring at all (not mechanical, not electrical).
Since this is a full frame lens, the 28mm focal length is practical for everyday use. It reminds me of
the Ricoh GR, which I like.
The lens is quite slow: f/4.5. I find it tolerable for FF, because the APS-C equivalent is f/3 - not much worse than the f/2.8 of the Ricoh GR. But don't expect fast autofocus in low light.
Unfortunately, f/4.5 is the only aperture. There is no aperture control. The camera displays f/4.5 and cannot change it, even in Av/M modes. For me, this is the main drawback. I would like to be able to use f/8: even two apertures (f/4.5 and f/8) would be enough.
It is funny that there is an octagonal diaphragm imitation:
Is it for better sunstars? I haven't tested it yet.
What I like most is the slider to use the lens without a cap. It protects the front optical element:
It is very practical! Fast opening/closing and small size.
And, by the way, there is no filter thread.
The lens has 6 elements (2 ED, 2 aspherical) in 6 groups.
(It looks as if the background image of the lens is reversed/mirrored. The largest optical element is actually closest to the camera)
Of course, the NX 30/2 is optically much better (in my opinion), but it is equivalent to the 45mm (it is not a wide-angle lens). The NX 20/2.8 (equiv. to FF 30/4.2) is optically comparable to the Viltrox 28/4.5.
And what the Sony a7c looks like with the Viltrox 28/4.5:
I like it.