telescopecomparison · 2-way
William Optics FLT 120 vs Tele Vue NP101is
William Optics
FLT 120
Best suited for intermediate imagers building a versatile kit running a backyard imaging setup.
Tele Vue
NP101is
Best suited for intermediate imagers building a versatile kit running a portable travel rig.
Key differences
+44% focal length
+19% aperture
Slower by 1.1 f-stops
Specifications
| Specification | William Optics FLT 120 | Tele Vue NP101is |
|---|---|---|
| Optics | ||
| Type | Refractor | Refractor |
| Optical design | Triplet APO | Petzval |
| Aperture | 120mm | 101mm |
| Focal length | 780mm | 540mm |
| Native f/ratio | f/6.5 | f/5.4 |
| Image circle | 44mm | 40mm |
| Full-frame support | Yes | Yes |
| Physical | ||
| Weight | 7.7kg | 4.5kg |
Advantages of William Optics FLT 120
- Tighter framing — 780mm vs 540mm focal length
- 19% more light-gathering aperture
Advantages of Tele Vue NP101is
- Wider field — 540mm vs 780mm focal length
- Faster optics at f/5.4 vs f/6.5
- Lighter (4.5kg vs 7.7kg) — easier to travel with
Best for — William Optics FLT 120
- Medium-sized galaxies and planetary nebulae
- Full-frame astro cameras and DSLRs
Best for — Tele Vue NP101is
- Large emission nebulae and star clusters
- Full-frame astro cameras and DSLRs
William Optics FLT 120 — typical FOV & scale
- With Full-frame (36×24mm, 3.76µm)FOV: 2.64° × 1.76°Scale: 0.99"/px
- With APS-C (23.5×15.7mm, 3.76µm)FOV: 1.73° × 1.15°Scale: 0.99"/px
- With IMX533 square (11.3×11.3mm, 3.76µm)FOV: 0.83° × 0.83°Scale: 0.99"/px
Tele Vue NP101is — typical FOV & scale
- With Full-frame (36×24mm, 3.76µm)FOV: 3.82° × 2.55°Scale: 1.44"/px
- With APS-C (23.5×15.7mm, 3.76µm)FOV: 2.49° × 1.67°Scale: 1.44"/px
- With IMX533 square (11.3×11.3mm, 3.76µm)FOV: 1.20° × 1.20°Scale: 1.44"/px
William Optics FLT 120 — recommended user
Best suited for intermediate imagers building a versatile kit running a backyard imaging setup.
Tele Vue NP101is — recommended user
Best suited for intermediate imagers building a versatile kit running a portable travel rig.