Yongnuo YN42.5mm F1.7M II 42mm
The 42.5mm focal length (85mm equivalent) and f/1.7 aperture deliver smooth bokeh and low-light capability in a tiny 146g body with STM autofocus. Its discreet, pocketable design integrates unobtrusively on small Micro Four Thirds bodies like the Panasonic G100 or Olympus E-M10 series. This lens is best for street photographers and budget-conscious portrait shooters who need a fast, lightweight prime for everyday candid work and environmental portraits.
Snapshot
Pros & Cons
Pros
- Strong build (91st percentile) 91st
- Strong af (87th percentile) 87th
Cons
- Below average user sentiment (4th percentile)
- Below average bokeh (14th percentile)
- Below average aperture (21st percentile)
- Below average versatility (33rd percentile)
What owners think
How owner sentiment changed over time
ExclusiveBased on when customers actually wrote their reviews - so you can see whether early praise held up.
Based on 9 dated customer reviews, grouped by calendar quarter. Period analysis is in English.
The proof
Performance
Specifications
Full Specifications
Optics
| Type | Prime |
| Focal Length Min | 42 |
| Focal Length Max | 42 |
| Elements | 9 |
| Groups | 8 |
| Coating | Multilayer Coating |
Aperture
| Max Aperture | f/22 |
| Min Aperture | f/1.7 |
| Constant | No |
| Diaphragm Blades | 7 |
Build
| Mount | Micro Four Thirds |
| Format | micro-four-thirds |
| Weight | 0.1 kg / 0.3 lbs |
| Filter Thread | 52 |
AF & Stabilization
| AF Type | STM stepper motor |
Focus
| Min Focus Distance | 300 |
| Max Magnification | 0.15x |
vs Competition
| Spec | Yongnuo YN42.5mm F1.7M II 42mm | Tamron Di III 17-70mm f/2.8 Di III-A VC RXD | Nikon NIKKOR Z 17-28mm f/2.8 | Sigma Contemporary 16-28mm f/2.8 DG DN | Panasonic Leica DG Vario-Elmarit H-ES12060 | Canon RF 28-70mm f/2.8 IS STM |
|---|---|---|---|---|---|---|
| Focal Length | 42mm | 17-70mm | 17-28mm | 16-28mm | 12-60mm | 28-70mm |
| Max Aperture | f/22 | f/2.8 | f/2.8 | f/2.8 | f/2.8 | f/22 |
| Mount | Micro Four Thirds | Fujifilm X | Nikon Z | Sony E | Micro Four Thirds | Canon RF |
| Stabilization | false | true | false | false | true | true |
| Weather Sealed | false | true | true | true | true | true |
| Weight (g) | 150 | 544 | 450 | 450 | 320 | 495 |
| AF Type | STM stepper motor | RXD | Stepping Motor | Stepping AF Motor | linear motor | STM |
| Lens Type | prime | zoom | zoom | zoom | zoom | zoom |
| Compare | Compare | Compare | Compare | Compare |
| Product | AF | Bokeh | Build | Macro | Optical | Aperture | User Sentiment | Versatility | Social Proof | Stabilization |
|---|---|---|---|---|---|---|---|---|---|---|
| Yongnuo YN42.5mm F1.7M II 42mm | 87.4 | 13.8 | 90.6 | 36.5 | 51.5 | 21 | 3.6 | 33.3 | 57.1 | 37.7 |
| Tamron Di III 17-70mm f/2.8 Di III-A VC RXD Compare | 53.7 | 87.1 | 69.8 | 85.8 | 91 | 84.3 | 63.5 | 89.3 | 85.4 | 83.3 |
| Nikon NIKKOR Z 17-28mm f/2.8 Compare | 87.4 | 87.1 | 76.1 | 85.8 | 88 | 84.3 | 90.8 | 67.3 | 69.6 | 37.7 |
| Sigma Contemporary 16-28mm f/2.8 DG DN Compare | 87.4 | 87.1 | 76.1 | 77.8 | 97.2 | 84.3 | 75.8 | 67.9 | 63.6 | 37.7 |
| Panasonic Leica DG Vario-Elmarit H-ES12060 Compare | 98.1 | 87.1 | 84.6 | 51.7 | 91 | 84.3 | 44.3 | 93.1 | 68.6 | 83.3 |
| Canon RF 28-70mm f/2.8 IS STM Compare | 87.4 | 24 | 72.9 | 80 | 86.2 | 21 | 98 | 76.8 | 89.4 | 98.6 |
Price
Value & Pricing
We started tracking prices for this product on Jun 4, 2026. The chart appears once we have more data.
Usage Scores
A full written review is coming soon. The specs, scores, prices and charts above are always up to date.
