telescopecomparison · 2-way
Radian Raptor 61 vs Radian Raptor 75
Key differences
-32% focal length
-19% aperture
Faster by 0.9 f-stops
Specifications
| Specification | Radian Raptor 61 | Radian Raptor 75 |
|---|---|---|
| Optics | ||
| Type | refractor | refractor |
| Optical design | Petzval quadruplet | Petzval quintuplet |
| Aperture | 61mm | 75mm |
| Focal length | 275mm | 405mm |
| Native f/ratio | f/4.5 | f/5.4 |
| Image circle | 44mm | 44mm |
| Full-frame support | No | Yes |
| Physical | ||
| Weight | 2.6kg | 4.5kg |
Advantages of Radian Raptor 61
- Wider field — 275mm vs 405mm focal length
- Faster optics at f/4.5 vs f/5.4
- Lighter (2.6kg vs 4.5kg) — easier to travel with
Advantages of Radian Raptor 75
- Tighter framing — 405mm vs 275mm focal length
- 23% more light-gathering aperture
Best for — Radian Raptor 61
- Wide-field nebulae and Milky Way regions
- Fast imaging — short exposures per sub
Best for — Radian Raptor 75
- Large emission nebulae and star clusters
- Full-frame astro cameras and DSLRs
Radian Raptor 61 — typical FOV & scale
- With Full-frame (36×24mm, 3.76µm)FOV: 7.50° × 5.00°Scale: 2.82"/px
- With APS-C (23.5×15.7mm, 3.76µm)FOV: 4.90° × 3.27°Scale: 2.82"/px
- With IMX533 square (11.3×11.3mm, 3.76µm)FOV: 2.35° × 2.35°Scale: 2.82"/px
Radian Raptor 75 — typical FOV & scale
- With Full-frame (36×24mm, 3.76µm)FOV: 5.09° × 3.40°Scale: 1.91"/px
- With APS-C (23.5×15.7mm, 3.76µm)FOV: 3.32° × 2.22°Scale: 1.91"/px
- With IMX533 square (11.3×11.3mm, 3.76µm)FOV: 1.60° × 1.60°Scale: 1.91"/px
Radian Raptor 61 — recommended user
Best suited for beginners and wide-field enthusiasts running a portable travel rig.
Radian Raptor 75 — recommended user
Best suited for beginners and wide-field enthusiasts running a portable travel rig.