What's the difference between the Voigtländer Ultron 27mm F2 X and the Viltrox Viltrox AF 33mm f/1.4?

The Ultron 27mm F2 X leads on a lighter 120g body, a more compact 23.5 mm barrel, closer 0.25 m focusing. The Viltrox AF 33mm f/1.4 leads on a brighter f/1.4 maximum aperture, autofocus at all, where the Ultron 27mm F2 X is manual focus only.

Which is smaller, the Voigtländer Ultron 27mm F2 X or the Viltrox Viltrox AF 33mm f/1.4?

The Ultron 27mm F2 X is the smaller, lighter lens at 120g and 23.5 mm long, versus 270g for the Viltrox AF 33mm f/1.4.

Which is faster, the Voigtländer Ultron 27mm F2 X or the Viltrox Viltrox AF 33mm f/1.4?

The Viltrox AF 33mm f/1.4 is the faster lens at f/1.4, against f/2 for the Ultron 27mm F2 X — brighter in low light and able to throw the background further out of focus.

Voigtländer Ultron 27mm F2 X vs Viltrox Viltrox AF 33mm f/1.4: full comparison

The Viltrox gives you f/1.4 and autofocus for less, and the Ultron is smaller, with better controls and manual focus.

Read the full Ultron 27mm F2 X review →Read the full Viltrox AF 33mm f/1.4 review →

The short version

This one comes down to autofocus and how the lens feels in your hand. The Viltrox AF 33mm f/1.4 has fast autofocus that's almost silent, even for video. The Ultron 27mm f/2 has no autofocus. The Viltrox came out in 2020 at around $239, and the Ultron costs around $600.

Check the view as well. On a Fujifilm X camera, the Viltrox shows about what a 50mm lens shows on a 35mm film camera. That's the classic normal view. The Ultron shows about 40mm, which is a little wider.

The Ultron wins on size and controls. It's 120g and 23.5 mm long, and the Viltrox is 270g and 72 mm long. The Ultron's aperture ring clicks in small steps. Its focus tab has a hard infinity stop, so the ring stops dead at infinity. The Viltrox aperture ring has no clicks and no numbers. You set it by watching the screen. That's smooth for video, but it's easy to move by accident in a bag.

Viltrox's own store no longer lists the X-mount version of this lens, so support for future cameras is uncertain. The Ultron is the newer lens, from 2023.

Where the Ultron 27mm F2 X wins

+a lighter 120g body
+a more compact 23.5 mm barrel
+closer 0.25 m focusing
+higher 0.15× magnification
+a 10-blade diaphragm

Where the Viltrox AF 33mm f/1.4 wins

+a brighter f/1.4 maximum aperture
+autofocus at all, where the Ultron 27mm F2 X is manual focus only

Who should buy the Ultron 27mm F2 X or Viltrox AF 33mm f/1.4?

Buy the Ultron 27mm F2 X if…

Pick the Ultron if you enjoy handling the camera. Its metal build, clicked aperture ring and small size suit slow street and travel shooting.

Buy the Viltrox AF 33mm f/1.4 if…

Pick the Viltrox if you want f/1.4 with autofocus for the least money. It's good for portraits, low light and video. It works best on subjects that don't move fast.

Ultron 27mm F2 X vs Viltrox AF 33mm f/1.4: pros and cons

Voigtländer Ultron 27mm F2 X	Viltrox Viltrox AF 33mm f/1.4
Sharp in the centre at f/2. The change from sharp to blurred is short, so subjects stand out. Blurred lights come out clean, with no rings inside them. Ten straight blades turn bright lights into ten-point stars from about f/2.8. All metal, with a focus tab and a hard stop at infinity. The camera knows the lens is on, so focus aids, stabilisation and photo data work. Focuses as close as 25 cm, close enough for small details.	f/1.4 autofocus normal prime at roughly a third of the native price. Strong centre sharpness from f/1.4, even across the frame by f/2.8. Fast, effectively silent stepping-motor autofocus — quiet enough for video. User-updatable firmware over a USB port in the mount. HD Nano coating handles backlight without the milky wash cheap glass shows.
No autofocus. Everything past a few metres is in a tiny turn of the focus ring. At f/2 the corners are softer than the XF 23mm F2 R WR's, until about f/8. No weather sealing, on a lens people put on sealed X-Pro and X-T bodies. Since firmware updates in 2024, some Fuji bodies save f/22 as the aperture. Around $600, about 1.5 times the price of Fujifilm's 27mm with autofocus.	Clickless, unmarked aperture ring — smooth for video, imprecise for stills. No weather sealing and no stabilization. 270g and 72 mm long, noticeably bigger than the XF 35mm F1.4 R. Compatibility depends on firmware; the original needed a hardware revision for the X-Pro3. Viltrox's own store no longer lists the X-mount version, so future support is uncertain.

Voigtländer Ultron 27mm F2 X

Viltrox Viltrox AF 33mm f/1.4

Sharp in the centre at f/2.
The change from sharp to blurred is short, so subjects stand out.
Blurred lights come out clean, with no rings inside them.
Ten straight blades turn bright lights into ten-point stars from about f/2.8.
All metal, with a focus tab and a hard stop at infinity.
The camera knows the lens is on, so focus aids, stabilisation and photo data work.
Focuses as close as 25 cm, close enough for small details.

f/1.4 autofocus normal prime at roughly a third of the native price.
Strong centre sharpness from f/1.4, even across the frame by f/2.8.
Fast, effectively silent stepping-motor autofocus — quiet enough for video.
User-updatable firmware over a USB port in the mount.
HD Nano coating handles backlight without the milky wash cheap glass shows.

No autofocus.
Everything past a few metres is in a tiny turn of the focus ring.
At f/2 the corners are softer than the XF 23mm F2 R WR's, until about f/8.
No weather sealing, on a lens people put on sealed X-Pro and X-T bodies.
Since firmware updates in 2024, some Fuji bodies save f/22 as the aperture.
Around $600, about 1.5 times the price of Fujifilm's 27mm with autofocus.

Clickless, unmarked aperture ring — smooth for video, imprecise for stills.
No weather sealing and no stabilization.
270g and 72 mm long, noticeably bigger than the XF 35mm F1.4 R.
Compatibility depends on firmware; the original needed a hardware revision for the X-Pro3.
Viltrox's own store no longer lists the X-mount version, so future support is uncertain.

Pros and cons mirror the in-house Ultron 27mm F2 X review and Viltrox AF 33mm f/1.4 review.

Ultron 27mm F2 X vs Viltrox AF 33mm f/1.4: full specs

Spec	Ultron 27mm F2 X 27 mm · f/2 · 120g	Viltrox AF 33mm f/1.4 33 mm · f/1.4 · 270g
Optical
Focal length	27 mm	33 mm
35mm equivalent	40 mm	50 mm
Maximum aperture	f/2	f/1.4
Minimum aperture	f/22	f/16
Optical construction	6 elements in 4 groups	10 elements in 9 groups
Special elements	1 extra-low-dispersion element, no aspherical glass	1 ED element, 1 high-refractive-index element, HD Nano coating
Aperture blades	10	9
Focus & Stabilization
Min. focus distance	0.25 m	0.40 m
Max. magnification	0.15×	0.1×
Autofocus motor	Manual focus only	Stepping motor
Optical stabilization	No	No
Physical
Filter thread	43 mm	52 mm
Diameter × length	59.3 × 23.5 mm	65 × 72 mm
Weight	120g	270g
Weather sealing	No	No
Min. operating temp	—	—
General
Announced	2023-05-15	2020-04-21

Highlighted cells are best in class between these two. Specs sourced from the manufacturers' public product pages.

In-depth reviews

For the full long-form review of each lens, see the Voigtländer Ultron 27mm F2 X review and the Viltrox Viltrox AF 33mm f/1.4 review. Each carries the full spec breakdown, pros and cons, and where the lens sits in the X-mount lineup.