Big Mike's BM-SLY420NK-K2 420-800mm
The 420-1600mm zoom range and constant f/8.3 aperture offer extreme reach in a lightweight 989g body, but the lens is entirely manual focus with no electronic communication. Its F-mount compatibility spans a wide range of Nikon DSLRs, making it a low-cost entry point for super-telephoto photography. This lens is best for budget-conscious Nikon DSLR users who are comfortable with manual focus and want to experiment with long-distance wildlife or sports shots in good light.
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.
The proof
Performance
Specifications
Full Specifications
Optics
| Type | Telephoto |
| Focal Length Min | 420 |
| Focal Length Max | 800 |
Aperture
| Max Aperture | f/8.3 |
| Min Aperture | f/8.3 |
| Constant | No |
Build
| Mount | Nikon F |
| Weight | 1.0 kg / 2.2 lbs |
AF & Stabilization
| AF Type | manual focus only |
| Stabilization | Yes |
Focus
| Min Focus Distance | 420 |
vs Competition
| Spec | Big Mike's BM-SLY420NK-K2 420-800mm | Tamron Di III VC 28-300mm f/4-7.1 VXD | Nikon NIKKOR Z DX 16-50mm f/3.5-6.3 VR | Sony E PZ 16-50mm f/3.5-5.6 OSS | Panasonic LUMIX S S-E100 | Canon EF-S 18-135mm f/3.5-5.6 IS USM |
|---|---|---|---|---|---|---|
| Focal Length | 420-800mm | 28-300mm | 16-50mm | 16-50mm | 100mm | 18-135mm |
| Max Aperture | f/8.3 | f/4 | f/3.5 | f/3.5 | f/2.8 | f/3.5 |
| Mount | Nikon F | Sony E | Nikon Z | Sony E | L-Mount | Canon EF-S |
| Stabilization | true | true | true | true | false | true |
| Weather Sealed | false | true | false | true | true | false |
| Weight (g) | 989 | 590 | 135 | 107 | 298 | 515 |
| AF Type | manual focus only | VXD linear motor | Stepping Motor | Autofocus | Dual phase linear motor | STM |
| Lens Type | telephoto | zoom | zoom | zoom | macro | zoom |
| Compare | Compare | Compare | Compare | Compare |
| Product | AF | Bokeh | Build | Macro | Optical | Aperture | User Sentiment | Versatility | Social Proof | Stabilization |
|---|---|---|---|---|---|---|---|---|---|---|
| Big Mike's BM-SLY420NK-K2 420-800mm | 13.3 | 47.9 | 6.1 | 62 | 20.2 | 49.8 | 3.7 | 69.8 | 64 | 82.4 |
| Tamron Di III VC 28-300mm f/4-7.1 VXD Compare | 98 | 78.2 | 65.1 | 85.8 | 96.7 | 66.3 | 91.2 | 97.7 | 55 | 82.4 |
| Nikon NIKKOR Z DX 16-50mm f/3.5-6.3 VR Compare | 86.9 | 75.7 | 92.7 | 45.2 | 74.1 | 77.6 | 0 | 83.3 | 80.6 | 95.3 |
| Sony E PZ 16-50mm f/3.5-5.6 OSS Compare | 53.9 | 75.7 | 98.5 | 43.9 | 68.3 | 77.6 | 63.7 | 83.3 | 80.6 | 93.3 |
| Panasonic LUMIX S S-E100 Compare | 98 | 87.3 | 85.8 | 82 | 83.4 | 84.2 | 80.9 | 33.6 | 64.8 | 36.8 |
| Canon EF-S 18-135mm f/3.5-5.6 IS USM Compare | 86.9 | 75.7 | 53 | 42.4 | 82.2 | 77.6 | 30 | 95.8 | 77.2 | 93.3 |