telescope
Borg
55FL
55mm Apo doublet fluorite · 250mm f/4.5
Compact fluorite.
Best for
- Wide-field nebulae and Milky Way regions
- Fast imaging — short exposures per sub
Specifications
| Optics | |
| Type | refractor |
| Optical design | Apo doublet fluorite |
| Aperture | 55mm |
| Focal length | 250mm |
| Native f/ratio | f/4.5 |
| Image circle | — |
| Full-frame support | No |
| Physical | |
| Weight | 1.2kg |
Typical FOV & image scale
With Full-frame (36×24mm, 3.76µm)
FOV 8.25° × 5.50°
Scale 3.10″/px
With APS-C (23.5×15.7mm, 3.76µm)
FOV 5.39° × 3.60°
Scale 3.10″/px
With IMX533 square (11.3×11.3mm, 3.76µm)
FOV 2.59° × 2.59°
Scale 3.10″/px
Typical targets
- Messier M45 — PleiadesReflection Nebula · 110′
- NGC NGC 7000 — North America NebulaEmission Nebula · 120′
- IC IC 2177 — Seagull NebulaEmission Nebula · 120′
- Messier M44 — Beehive ClusterOpen Cluster · 95′
- Messier M8 — Lagoon NebulaEmission Nebula · 90′
- Messier M24 — Sagittarius Star CloudOpen Cluster · 90′
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