telescopecomparison · 2-way
Sky-Watcher Esprit 120ED vs Borg 90FL
Sky-Watcher
Esprit 120ED
Best suited for intermediate imagers building a versatile kit running a backyard imaging setup.
Key differences
+68% focal length
+33% aperture
Slower by 1.4 f-stops
Specifications
| Specification | Sky-Watcher Esprit 120ED | Borg 90FL |
|---|---|---|
| Optics | ||
| Type | Refractor | refractor |
| Optical design | Triplet APO | Apo doublet fluorite |
| Aperture | 120mm | 90mm |
| Focal length | 840mm | 500mm |
| Native f/ratio | f/7.0 | f/5.6 |
| Image circle | 44mm | — |
| Full-frame support | Yes | No |
| Physical | ||
| Weight | 11.5kg | 2.5kg |
Advantages of Sky-Watcher Esprit 120ED
- Tighter framing — 840mm vs 500mm focal length
- 33% more light-gathering aperture
- Larger image circle (44mm) — supports bigger sensors
Advantages of Borg 90FL
- Wider field — 500mm vs 840mm focal length
- Faster optics at f/5.6 vs f/7
- Lighter (2.5kg vs 11.5kg) — easier to travel with
Best for — Sky-Watcher Esprit 120ED
- Medium-sized galaxies and planetary nebulae
- Full-frame astro cameras and DSLRs
Best for — Borg 90FL
- Large emission nebulae and star clusters
Sky-Watcher Esprit 120ED — typical FOV & scale
- With Full-frame (36×24mm, 3.76µm)FOV: 2.46° × 1.64°Scale: 0.92"/px
- With APS-C (23.5×15.7mm, 3.76µm)FOV: 1.60° × 1.07°Scale: 0.92"/px
- With IMX533 square (11.3×11.3mm, 3.76µm)FOV: 0.77° × 0.77°Scale: 0.92"/px
Borg 90FL — typical FOV & scale
- With Full-frame (36×24mm, 3.76µm)FOV: 4.13° × 2.75°Scale: 1.55"/px
- With APS-C (23.5×15.7mm, 3.76µm)FOV: 2.69° × 1.80°Scale: 1.55"/px
- With IMX533 square (11.3×11.3mm, 3.76µm)FOV: 1.29° × 1.29°Scale: 1.55"/px
Sky-Watcher Esprit 120ED — recommended user
Best suited for intermediate imagers building a versatile kit running a backyard imaging setup.
Borg 90FL — recommended user
Best suited for beginners and wide-field enthusiasts running a portable travel rig.