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
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 VC VXD Lightweight A074 | Nikon NIKKOR Z DX 16-50mm f/3.5-6.3 VR | Sirui Sniper 75mm Autofocus F1.2 Telephoto APS-C Cine | Canon EF-S 18-135mm f/3.5-5.6 IS USM | Panasonic LUMIX S S-E100 |
|---|---|---|---|---|---|---|
| Focal Length | 42mm | 28-300mm | 16-50mm | 75mm | 18-135mm | 100mm |
| Max Aperture | f/22 | f/7.1 | f/3.5 | f/1.2 | f/3.5 | f/2.8 |
| Mount | Micro Four Thirds | Sony E | Nikon Z | Sony E | Canon EF-S | L-Mount |
| Stabilization | false | true | true | true | true | false |
| Weather Sealed | false | true | false | false | false | true |
| Weight (g) | 150 | 590 | 135 | 466 | 515 | 298 |
| AF Type | STM stepper motor | VXD linear motor | Stepping Motor | STM | NANO USM | Dual Phase Linear Motor |
| Lens Type | prime | zoom | zoom | telephoto | zoom | macro |
| 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 | 87.2 | 13.4 | 90.8 | 37.4 | 52.7 | 20.5 | 3.7 | 33.7 | 59 | 37 |
| Tamron Di III VC VXD Lightweight A074 Compare | 53.4 | 77.3 | 65.3 | 85.1 | 96.6 | 65.6 | 91.2 | 97.7 | 54.3 | 82.7 |
| Nikon NIKKOR Z DX 16-50mm f/3.5-6.3 VR Compare | 87.2 | 74.7 | 92.8 | 44.9 | 74.6 | 76.8 | 0 | 83.2 | 80.1 | 95.5 |
| Sirui Sniper 75mm Autofocus F1.2 Telephoto APS-C Cine Compare | 87.2 | 99.5 | 59.3 | 94.5 | 87.6 | 98.5 | 15.9 | 33.7 | 84.7 | 82.7 |
| Canon EF-S 18-135mm f/3.5-5.6 IS USM Compare | 87.2 | 74.7 | 54.2 | 42.2 | 82.6 | 76.8 | 0 | 95.8 | 76.6 | 93.5 |
| Panasonic LUMIX S S-E100 Compare | 98.1 | 86.4 | 86.2 | 81.4 | 83.7 | 83.4 | 80.9 | 33.7 | 64.2 | 37 |
Price
Value & Pricing
Amazon 1 offer From $138
We started tracking prices for this product on Jun 3, 2026. The chart appears once we have more data.
