telescopecomparison · 2-way
William Optics FLT 120 vs Sky-Watcher Esprit 100ED
William Optics
FLT 120
Best suited for intermediate imagers building a versatile kit running a backyard imaging setup.
Sky-Watcher
Esprit 100ED
Best suited for intermediate imagers building a versatile kit running a backyard imaging setup.
Key differences
+42% focal length
+20% aperture
Slower by 1.0 f-stops
Specifications
| Specification | William Optics FLT 120 | Sky-Watcher Esprit 100ED |
|---|---|---|
| Optics | ||
| Type | Refractor | Refractor |
| Optical design | Triplet APO | Triplet APO |
| Aperture | 120mm | 100mm |
| Focal length | 780mm | 550mm |
| Native f/ratio | f/6.5 | f/5.5 |
| Image circle | 44mm | 44mm |
| Full-frame support | Yes | Yes |
| Physical | ||
| Weight | 7.7kg | 8.6kg |
Advantages of William Optics FLT 120
- Tighter framing — 780mm vs 550mm focal length
- 20% more light-gathering aperture
Advantages of Sky-Watcher Esprit 100ED
- Wider field — 550mm vs 780mm focal length
- Faster optics at f/5.5 vs f/6.5
Best for — William Optics FLT 120
- Medium-sized galaxies and planetary nebulae
- Full-frame astro cameras and DSLRs
Best for — Sky-Watcher Esprit 100ED
- 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
Sky-Watcher Esprit 100ED — typical FOV & scale
- With Full-frame (36×24mm, 3.76µm)FOV: 3.75° × 2.50°Scale: 1.41"/px
- With APS-C (23.5×15.7mm, 3.76µm)FOV: 2.45° × 1.64°Scale: 1.41"/px
- With IMX533 square (11.3×11.3mm, 3.76µm)FOV: 1.18° × 1.18°Scale: 1.41"/px
William Optics FLT 120 — recommended user
Best suited for intermediate imagers building a versatile kit running a backyard imaging setup.
Sky-Watcher Esprit 100ED — recommended user
Best suited for intermediate imagers building a versatile kit running a backyard imaging setup.