Specifications#
- Brand
- Viltrox
- Model
- PFU RBMH 20mm f/1.8 ASPH
- Lens type
- Ultra-wide prime
- Focal length
- 20 mm
- Maximum aperture
- f/1.8
- Image circle
- Full frame (36×24 mm)
- Mount(s)
- Sony E-mount, Nikon Z
- Projection
- Rectilinear
- Lensfun correction profile
- Yes — distortion/vignetting/TCA
Equivalent focal length on different cameras#
Field of view and depth-of-field equivalence when this lens is used on bodies with different sensor sizes (natively or via an adapter).
| Camera format | At 20 mm | Equiv. aperture (DoF) |
|---|---|---|
| Full frame | 20 mm · 94° | f/1.8 |
| APS-C | 30 mm · 70° | f/2.7 |
| APS-C (Canon) | 32 mm · 68° | f/2.9 |
| Micro Four Thirds | 40 mm · 57° | f/3.6 |
Depth of field & background blur#
Computed on its native Full frame format (CoC 30 µm). “Blur @2 m” is the size of an out-of-focus point at infinity, as a percentage of frame width, with the subject at 2 m — a simple bokeh index. Full table: 20 mm f/1.8 on full frame.
| Focal | Aperture | at 1 m | at 2 m | at 5 m | at 10 m | Hyperfocal | Blur @2 m |
|---|---|---|---|---|---|---|---|
| 20 mm | f/1.8 | 26.9 cm | 1.15 m | 12.3 m | ∞ | 7.43 m | 0.3% |
| 20 mm | f/4 | 64.4 cm | 3.67 m | ∞ | ∞ | 3.35 m | 0.1% |
| 20 mm | f/8 | 1.80 m | ∞ | ∞ | ∞ | 1.69 m | 0.1% |
Handheld & night-sky limits#
NPF assumes typical 20–24 MP sensors (≈6 µm pixels on full frame, ≈3.9 µm on APS-C, ≈3.3 µm on Micro Four Thirds).
| Body | Min. handheld shutter (longest focal) | 500 rule at 20 mm | NPF at 20 mm, f/1.8 |
|---|---|---|---|
| Full frame | 1/20 s | 25 s | 12 s |
| APS-C | 1/30 s | 17 s | 9 s |
| APS-C (Canon) | 1/30 s | 16 s | 9 s |
| Micro Four Thirds | 1/40 s | 12 s | 8 s |
Compatible cameras#
Bodies in our database with a native Sony E-mount and Nikon Z mount.
- Sony α7R VI 2026
- Nikon Z5II 2025
- Sony α7 V 2025
- Nikon ZR 2025
- Sony ZV-E10 II 2024
- Sony α1 II 2024
- Sony α9 III 2024
- Nikon Z50II 2024
- Nikon Z6III 2024
- Nikon Z8 2023
- Nikon Zf 2023
- Sony α6700 2023
- Sony ZV-E1 2023
- Sony α7C II 2023
- Sony α7CR 2023
- Sony α7R V 2022
- Nikon Z30 2022
- Sony FX30 2022
- Sony FX3 2021
- Sony ZV-E10 2021
- Sony α1 2021
- Nikon Z9 2021
- Nikon Zfc 2021
- Sony α7 IV 2021
- Sony α7S III 2020
- Nikon Z5 2020
- Nikon Z7II 2020
- Nikon Z6II 2020
- Sony FX6 2020
- Sony α7R IV 2019
- Nikon Z50 2019
- Sony α6400 2019
- Sony α6600 2019
- Sony α6100 2019
- Nikon Z6 2018
- Nikon Z7 2018
- Sony α7 III 2018
- Sony α6300 2016
- Sony α6500 2016
- Sony α7R II 2015
Adapt it to other systems#
Similar lenses#
- Sony FE 20mm f/1.8 G f/1.8
- Nikon Nikkor Z 20mm f/1.8 S f/1.8
- Samyang 20mm f/1.8 ED AS UMC f/1.8
- Sigma 20mm F2 DG DN | Contemporary 022 f/2
- Tamron 20mm F2.8 Di III OSD M1:2 f/2.8
- Viltrox AF 20mm F2.8 Z f/2.8
- Sigma 19mm f/2.8 DN f/2.8
- Sigma 19mm f/2.8 EX DN f/2.8
- Samyang AF 18mm f/2.8 f/2.8
- Zeiss Batis 18mm f/2.8 f/2.8
- Zeiss Distagon 18mm f/4 f/4
- Sigma 17mm F4 DG DN | Contemporary 023 f/4
Frequently asked questions#
Is the Viltrox PFU RBMH 20mm f/1.8 ASPH full frame?
Yes — it covers the full 36 × 24 mm frame.
What is the Viltrox PFU RBMH 20mm f/1.8 ASPH equivalent to on APS-C?
On a 1.5× APS-C body it frames like 30 mm, and like 32 mm on Canon APS-C.
What is the Viltrox PFU RBMH 20mm f/1.8 ASPH good for?
As a ultra-wide prime it suits astrophotography, landscapes and dramatic perspectives.
Sources & licences#
- Lensfun lens database — CC BY-SA 3.0
Last updated October 03, 2026 · How we calculate · Sources