telescopecomparison · 2-way
Astro-Tech AT8RC vs William Optics FLT 156
William Optics
FLT 156
Best suited for intermediate imagers building a versatile kit running a backyard imaging setup.
Key differences
+50% focal length
+30% aperture
Slower by 1.0 f-stops
Specifications
| Specification | Astro-Tech AT8RC | William Optics FLT 156 |
|---|---|---|
| Optics | ||
| Type | RC | refractor |
| Optical design | Ritchey-Chrétien | Apo triplet FPL-53 |
| Aperture | 203mm | 156mm |
| Focal length | 1624mm | 1085mm |
| Native f/ratio | f/8.0 | f/7.0 |
| Image circle | 42mm | 52mm |
| Full-frame support | Yes | Yes |
| Physical | ||
| Weight | 10.0kg | 11.5kg |
Advantages of Astro-Tech AT8RC
- Tighter framing — 1624mm vs 1085mm focal length
- 30% more light-gathering aperture
Advantages of William Optics FLT 156
- Wider field — 1085mm vs 1624mm focal length
- Faster optics at f/7 vs f/8
- Larger image circle (52mm) — supports bigger sensors
Best for — Astro-Tech AT8RC
- Small galaxies, planetary nebulae, lunar & planetary detail
- High-resolution long-exposure work
- Faint-object imaging under dark skies
- Full-frame astro cameras and DSLRs
Best for — William Optics FLT 156
- Medium-sized galaxies and planetary nebulae
- Full-frame astro cameras and DSLRs
Astro-Tech AT8RC — typical FOV & scale
- With Full-frame (36×24mm, 3.76µm)FOV: 1.27° × 0.85°Scale: 0.48"/px
- With APS-C (23.5×15.7mm, 3.76µm)FOV: 0.83° × 0.55°Scale: 0.48"/px
- With IMX533 square (11.3×11.3mm, 3.76µm)FOV: 0.40° × 0.40°Scale: 0.48"/px
William Optics FLT 156 — typical FOV & scale
- With Full-frame (36×24mm, 3.76µm)FOV: 1.90° × 1.27°Scale: 0.71"/px
- With APS-C (23.5×15.7mm, 3.76µm)FOV: 1.24° × 0.83°Scale: 0.71"/px
- With IMX533 square (11.3×11.3mm, 3.76µm)FOV: 0.60° × 0.60°Scale: 0.71"/px
Astro-Tech AT8RC — recommended user
Best suited for experienced imagers chasing detail running a backyard imaging setup.
William Optics FLT 156 — recommended user
Best suited for intermediate imagers building a versatile kit running a backyard imaging setup.