Astro-Tech AT90EDX
Astro-Tech
Astro-Tech AT90EDX is a 90 mm ED triplet APO refractor for wide-to-mid-field nebulae and general deep-sky imaging.
Best Current Offer
Specifications
Optics
- Optical design
- ED triplet APO refractor
- Aperture
- 90 mm
- Focal length
- 540 mm
- Focal ratio
- f/6
- Dawes limit
- 1.29"
- Glass / elements
- Air-spaced ED triplet objective
Specifications
- Focuser
- 3.2\" dual-speed rotating rack & pinion, 10:1 fine focus
Imaging
- Camera format
- APS-C / full-frame with matching flattener
- Full-frame coverage
- Yes
- Back focus
- Requires field flattener/reducer spacing for imaging
Astrophotography Fit
Best for wide-to-mid-field nebulae and general deep-sky imaging when the mount, camera format, and correction hardware are chosen as one system.
Astro-Tech AT90EDX sits in the telescope slot for wide-to-mid-field nebulae and general deep-sky imaging. The useful headline specs are aperture 90 mm, focal length 540 mm, f/6.
Camera coverage: APS-C / full-frame with matching flattener. Back focus: Requires field flattener/reducer spacing for imaging.
Refractors keep the field routine calmer: no regular collimation, predictable cooldown, and a clean path to autofocus and filtered imaging. The tradeoff is aperture and reach.
Best paired with
- Corrected field flattener or reducer when the design requires one
- Cooled APS-C or smaller astro cameras matched to the image circle
- Autofocus, guide scope or OAG, and a mount with comfortable payload margin
Not recommended for
- Large full-frame sensors unless the corrected field supports them
- Very small travel mounts near their realistic imaging payload limit
- Buyers expecting one telescope to be ideal for every target size
Where To Buy
Some links on this page are affiliate links. Prices and availability are pulled automatically from each retailer and updated daily.
| Retailer | Price | Availability | View Offer |
|---|---|---|---|
| Astronomics Astronomics | $1,574.00 | In stock Updated 5/14/2026 | View Offer - $1,574.00 |