telescopecomparison · 2-way
Tele Vue TV-85 vs Askar FRA500
Tele Vue
TV-85
Best suited for intermediate imagers building a versatile kit running a portable travel rig.
Key differences
+20% focal length
-6% aperture
Slower by 1.4 f-stops
Specifications
| Specification | Tele Vue TV-85 | Askar FRA500 |
|---|---|---|
| Optics | ||
| Type | refractor | Refractor |
| Optical design | Apo doublet | Petzval Quintuplet APO |
| Aperture | 85mm | 90mm |
| Focal length | 600mm | 500mm |
| Native f/ratio | f/7.0 | f/5.6 |
| Image circle | — | 60mm |
| Full-frame support | No | Yes |
| Physical | ||
| Weight | 2.9kg | 5.4kg |
Advantages of Tele Vue TV-85
- Tighter framing — 600mm vs 500mm focal length
- Lighter (2.9kg vs 5.4kg) — easier to travel with
Advantages of Askar FRA500
- Wider field — 500mm vs 600mm focal length
- Faster optics at f/5.6 vs f/7
- Larger image circle (60mm) — supports bigger sensors
Best for — Tele Vue TV-85
- Large emission nebulae and star clusters
Best for — Askar FRA500
- Large emission nebulae and star clusters
- Full-frame astro cameras and DSLRs
Tele Vue TV-85 — typical FOV & scale
- With Full-frame (36×24mm, 3.76µm)FOV: 3.44° × 2.29°Scale: 1.29"/px
- With APS-C (23.5×15.7mm, 3.76µm)FOV: 2.24° × 1.50°Scale: 1.29"/px
- With IMX533 square (11.3×11.3mm, 3.76µm)FOV: 1.08° × 1.08°Scale: 1.29"/px
Askar FRA500 — typical FOV & scale
- With Full-frame (36×24mm, 3.76µm)FOV: 4.13° × 2.75°Scale: 1.55"/px
- With APS-C (23.5×15.7mm, 3.76µm)FOV: 2.69° × 1.80°Scale: 1.55"/px
- With IMX533 square (11.3×11.3mm, 3.76µm)FOV: 1.29° × 1.29°Scale: 1.55"/px
Tele Vue TV-85 — recommended user
Best suited for intermediate imagers building a versatile kit running a portable travel rig.
Askar FRA500 — recommended user
Best suited for beginners and wide-field enthusiasts running a backyard imaging setup.