Agena 1.25" Reticle Eyepiece with Focusable Dual Crosshair - 20mm
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- Premium quality 20mm 1.25" centering / alignment / tracking eyepiece
- 5 lens elements in 4 groups with blackened lens edges provide bright views with a wide 70° apparent field of view
- Comfortable 16mm eye relief
- Dual crosshairs are focusable - great if you wear glasses
- Excellent for accurate polar alignment, goto alignment, and centering guide stars for astrophotography
- Reticle is not illuminated
A reticle eyepiece is virtually indispensable for serious astronomy observing and astrophotography. The Agena 20mm reticle eyepiece boasts a double line crosshair laser etched into optical glass that extends from edge to edge. It greatly simplifies centering celestial objects in the eyepiece for more accurate go-to alignments.
Unlike single line crosshairs in other illuminated reticle eyepieces, the double line design doesn’t obscure small targets when attempting to center them – they remain visible in the small box created by the intersection of the two pairs of double lines. Alignment can also be achieved by putting the object at the intersection of any two perpendicular lines. The reticle can be rotated and facilitates polar drift alignment routines for equatorial mounts and precision guiding for astrophotography. Eyeglass wearers will appreciate the focusing mechanism that allows them to bring the reticle to a sharp focus.
The 20mm focal length provides a wide 70° apparent view of the sky allowing you to find objects and alignment stars more easily than shorter focal length eyepieces, while maintaining good eye relief, especially when compared with other higher-power reticle eyepieces (just use a barlow with this eyepiece if you want even more magnification/accuracy).
Note that this eyepiece does not include an illuminator to light up the reticle pattern with red light. The eyepiece features a standard 8mm metric illuminator female thread (M8x0.75 specification) which accepts many (but not all) commonly sold illuminators if you wish to convert it into an illuminated reticle eyepiece yourself.
Please note: This eyepiece was deliberately designed with a large center box compared to what you might be accustomed to with most other reticle eyepieces. This was based on requests from many customers who primarily wanted an alignment eyepiece that was easier to use without excessive squinting and straining. Others who want to use this eyepiece for critical tracking can simply defocus a star to where it occupies the center box, and its tracking/guiding will be just as accurate as using a smaller star image with a smaller central crosshair box.
| Free Shipping Graphic | Free US Shipping |
|---|---|
| Eyepiece Series | SWA (Super Wide Angle) |
| Focal Length | 20mm |
| Barrel Size | 1.25" (31.7mm) |
| Apparent Field of View (Mfg Specified) | 70° |
| Eye Relief (Designed) | 16mm |
| Filter Threads | Standard 1.25" Filter Thread (M28.5 x 0.6) |
| Coatings | Fully Broadband Multi-Coated |
| Lens Elements | 5 |
| Lens Groups | 4 |
| Blackened Lens Edges | Yes |
| Barrel Type | With safety undercut |
| Protective Plastic Storage Container | No |
| Height (With Eyeguard Extended) | 81mm |
| Maximum Width | 54mm |
| End Caps | 2 |
| Rubber Eye Guard | Yes |
| Weight | 6.7oz |
| Hide Found a better Shipped Price on Frontend? | No |
- Premium quality 20mm 1.25" centering / alignment / tracking eyepiece
- 5 lens elements in 4 groups with blackened lens edges provide bright views with a wide 70° apparent field of view
- Comfortable 16mm eye relief
- Dual crosshairs are focusable - great if you wear glasses
- Excellent for accurate polar alignment, goto alignment, and centering guide stars for astrophotography
- Reticle is not illuminated
A reticle eyepiece is virtually indispensable for serious astronomy observing and astrophotography. The Agena 20mm reticle eyepiece boasts a double line crosshair laser etched into optical glass that extends from edge to edge. It greatly simplifies centering celestial objects in the eyepiece for more accurate go-to alignments.
Unlike single line crosshairs in other illuminated reticle eyepieces, the double line design doesn’t obscure small targets when attempting to center them – they remain visible in the small box created by the intersection of the two pairs of double lines. Alignment can also be achieved by putting the object at the intersection of any two perpendicular lines. The reticle can be rotated and facilitates polar drift alignment routines for equatorial mounts and precision guiding for astrophotography. Eyeglass wearers will appreciate the focusing mechanism that allows them to bring the reticle to a sharp focus.
The 20mm focal length provides a wide 70° apparent view of the sky allowing you to find objects and alignment stars more easily than shorter focal length eyepieces, while maintaining good eye relief, especially when compared with other higher-power reticle eyepieces (just use a barlow with this eyepiece if you want even more magnification/accuracy).
Note that this eyepiece does not include an illuminator to light up the reticle pattern with red light. The eyepiece features a standard 8mm metric illuminator female thread (M8x0.75 specification) which accepts many (but not all) commonly sold illuminators if you wish to convert it into an illuminated reticle eyepiece yourself.
Please note: This eyepiece was deliberately designed with a large center box compared to what you might be accustomed to with most other reticle eyepieces. This was based on requests from many customers who primarily wanted an alignment eyepiece that was easier to use without excessive squinting and straining. Others who want to use this eyepiece for critical tracking can simply defocus a star to where it occupies the center box, and its tracking/guiding will be just as accurate as using a smaller star image with a smaller central crosshair box.
| Free Shipping Graphic | Free US Shipping |
|---|---|
| Eyepiece Series | SWA (Super Wide Angle) |
| Focal Length | 20mm |
| Barrel Size | 1.25" (31.7mm) |
| Apparent Field of View (Mfg Specified) | 70° |
| Eye Relief (Designed) | 16mm |
| Filter Threads | Standard 1.25" Filter Thread (M28.5 x 0.6) |
| Coatings | Fully Broadband Multi-Coated |
| Lens Elements | 5 |
| Lens Groups | 4 |
| Blackened Lens Edges | Yes |
| Barrel Type | With safety undercut |
| Protective Plastic Storage Container | No |
| Height (With Eyeguard Extended) | 81mm |
| Maximum Width | 54mm |
| End Caps | 2 |
| Rubber Eye Guard | Yes |
| Weight | 6.7oz |
| Hide Found a better Shipped Price on Frontend? | No |
Agena 1.25" Reticle Eyepiece with Focusable Dual Crosshair - 20mm