telescopecomparison · 2-way
William Optics FLT 120 vs SharpStar 61EDPH III
William Optics
FLT 120
Best suited for intermediate imagers building a versatile kit running a backyard imaging setup.
SharpStar
61EDPH III
Best suited for beginners and wide-field enthusiasts running a portable travel rig.
Key differences
+133% focal length
+97% aperture
Slower by 1.0 f-stops
Specifications
| Specification | William Optics FLT 120 | SharpStar 61EDPH III |
|---|---|---|
| Optics | ||
| Type | Refractor | Refractor |
| Optical design | Triplet APO | Doublet APO |
| Aperture | 120mm | 61mm |
| Focal length | 780mm | 335mm |
| Native f/ratio | f/6.5 | f/5.5 |
| Image circle | 44mm | 32mm |
| Full-frame support | Yes | No |
| Physical | ||
| Weight | 7.7kg | 2.4kg |
Advantages of William Optics FLT 120
- Tighter framing — 780mm vs 335mm focal length
- 97% more light-gathering aperture
- Larger image circle (44mm) — supports bigger sensors
Advantages of SharpStar 61EDPH III
- Wider field — 335mm vs 780mm focal length
- Faster optics at f/5.5 vs f/6.5
- Lighter (2.4kg vs 7.7kg) — easier to travel with
Best for — William Optics FLT 120
- Medium-sized galaxies and planetary nebulae
- Full-frame astro cameras and DSLRs
Best for — SharpStar 61EDPH III
- Wide-field nebulae and Milky Way regions
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
SharpStar 61EDPH III — typical FOV & scale
- With Full-frame (36×24mm, 3.76µm)FOV: 6.16° × 4.11°Scale: 2.32"/px
- With APS-C (23.5×15.7mm, 3.76µm)FOV: 4.02° × 2.69°Scale: 2.32"/px
- With IMX533 square (11.3×11.3mm, 3.76µm)FOV: 1.93° × 1.93°Scale: 2.32"/px
William Optics FLT 120 — recommended user
Best suited for intermediate imagers building a versatile kit running a backyard imaging setup.
SharpStar 61EDPH III — recommended user
Best suited for beginners and wide-field enthusiasts running a portable travel rig.