telescopecomparison · 2-way
Astro-Physics 92mm f/6.65 Stowaway vs William Optics FLT 91
Astro-Physics
92mm f/6.65 Stowaway
Best suited for intermediate imagers building a versatile kit running a portable travel rig.
William Optics
FLT 91
Best suited for intermediate imagers building a versatile kit running a portable travel rig.
Key differences
+13% focal length
Slower by 0.8 f-stops
Specifications
| Specification | Astro-Physics 92mm f/6.65 Stowaway | William Optics FLT 91 |
|---|---|---|
| Optics | ||
| Type | refractor | Refractor |
| Optical design | Apo triplet | Triplet APO |
| Aperture | 92mm | 91mm |
| Focal length | 612mm | 540mm |
| Native f/ratio | f/6.7 | f/5.9 |
| Image circle | — | 44mm |
| Full-frame support | No | Yes |
| Physical | ||
| Weight | 3.2kg | 4.5kg |
Advantages of Astro-Physics 92mm f/6.65 Stowaway
- Tighter framing — 612mm vs 540mm focal length
- Lighter (3.2kg vs 4.5kg) — easier to travel with
Advantages of William Optics FLT 91
- Wider field — 540mm vs 612mm focal length
- Faster optics at f/5.9 vs f/6.65
- Larger image circle (44mm) — supports bigger sensors
Best for — Astro-Physics 92mm f/6.65 Stowaway
- Large emission nebulae and star clusters
Best for — William Optics FLT 91
- Large emission nebulae and star clusters
- Full-frame astro cameras and DSLRs
Astro-Physics 92mm f/6.65 Stowaway — typical FOV & scale
- With Full-frame (36×24mm, 3.76µm)FOV: 3.37° × 2.25°Scale: 1.27"/px
- With APS-C (23.5×15.7mm, 3.76µm)FOV: 2.20° × 1.47°Scale: 1.27"/px
- With IMX533 square (11.3×11.3mm, 3.76µm)FOV: 1.06° × 1.06°Scale: 1.27"/px
William Optics FLT 91 — 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
Astro-Physics 92mm f/6.65 Stowaway — recommended user
Best suited for intermediate imagers building a versatile kit running a portable travel rig.
William Optics FLT 91 — recommended user
Best suited for intermediate imagers building a versatile kit running a portable travel rig.
