telescope
Askar
FRA500
90mm Petzval Quintuplet APO · 500mm f/5.6
Quintuplet Petzval astrograph; 60mm image circle.
Best for
- Large emission nebulae and star clusters
- Full-frame astro cameras and DSLRs
Specifications
| Optics | |
| Type | Refractor |
| Optical design | Petzval Quintuplet APO |
| Aperture | 90mm |
| Focal length | 500mm |
| Native f/ratio | f/5.6 |
| Image circle | 60mm |
| Full-frame support | Yes |
| Physical | |
| Weight | 5.4kg |
Typical FOV & image 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
Recommended accessories
- Askar ASKAR 0.8x Reducer for FRA400/FRA500reducer · 0.8× focal lengthmanufacturer supported
- Askar FRA 0.7x Reducerreducer · 0.7× focal lengthmanufacturer supported
Typical targets
- Messier M48 — Open Cluster M48Open Cluster · 54′
- IC IC 434 — Horsehead NebulaEmission Nebula · 60′
- NGC NGC 869/884 — Double ClusterOpen Cluster · 60′
- NGC NGC 2264 — Christmas Tree ClusterEmission Nebula · 60′
- NGC NGC 6992 — Eastern VeilSupernova Remnant · 60′
- NGC NGC 7822 — Cepheus HII RegionEmission Nebula · 60′
Recommended cameras
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