telescopecomparison · 2-way
Orion 8" f/3.9 Newtonian Astrograph vs Astro-Tech AT115EDT
Orion
8" f/3.9 Newtonian Astrograph
Best suited for intermediate imagers building a versatile kit running a backyard imaging setup.
Astro-Tech
AT115EDT
Best suited for intermediate imagers building a versatile kit running a backyard imaging setup.
Key differences
+77% aperture
Faster by 3.1 f-stops
Specifications
| Specification | Orion 8" f/3.9 Newtonian Astrograph | Astro-Tech AT115EDT |
|---|---|---|
| Optics | ||
| Type | newtonian | refractor |
| Optical design | Newtonian astrograph | Apo triplet FPL-53 |
| Aperture | 203mm | 115mm |
| Focal length | 800mm | 805mm |
| Native f/ratio | f/3.9 | f/7.0 |
| Image circle | — | 52mm |
| Full-frame support | No | Yes |
| Physical | ||
| Weight | 10.5kg | 6.6kg |
Advantages of Orion 8" f/3.9 Newtonian Astrograph
- 77% more light-gathering aperture
- Faster optics at f/3.9 vs f/7
Advantages of Astro-Tech AT115EDT
- Larger image circle (52mm) — supports bigger sensors
- Lighter (6.6kg vs 10.5kg) — easier to travel with
Best for — Orion 8" f/3.9 Newtonian Astrograph
- Medium-sized galaxies and planetary nebulae
- Fast imaging — short exposures per sub
- Faint-object imaging under dark skies
Best for — Astro-Tech AT115EDT
- Medium-sized galaxies and planetary nebulae
- Full-frame astro cameras and DSLRs
Orion 8" f/3.9 Newtonian Astrograph — typical FOV & scale
- With Full-frame (36×24mm, 3.76µm)FOV: 2.58° × 1.72°Scale: 0.97"/px
- With APS-C (23.5×15.7mm, 3.76µm)FOV: 1.68° × 1.12°Scale: 0.97"/px
- With IMX533 square (11.3×11.3mm, 3.76µm)FOV: 0.81° × 0.81°Scale: 0.97"/px
Astro-Tech AT115EDT — typical FOV & scale
- With Full-frame (36×24mm, 3.76µm)FOV: 2.56° × 1.71°Scale: 0.96"/px
- With APS-C (23.5×15.7mm, 3.76µm)FOV: 1.67° × 1.12°Scale: 0.96"/px
- With IMX533 square (11.3×11.3mm, 3.76µm)FOV: 0.80° × 0.80°Scale: 0.96"/px
Orion 8" f/3.9 Newtonian Astrograph — recommended user
Best suited for intermediate imagers building a versatile kit running a backyard imaging setup.
Astro-Tech AT115EDT — recommended user
Best suited for intermediate imagers building a versatile kit running a backyard imaging setup.
