Orion Optics UK 50mm Straight-Through Wide Field Finder
- 50mm Aperture
- Straight-Through Optical Path
- Fully Coated Optics
- Integrated Crosshairs for Centering
- Quick-Release Dovetail Shoe
With its 50mm objective lens, the Orion Optics UK Straight Finder captures bright, wide-field views for intuitive manual star-hopping, even in an era of GoTo technology. This 50mm aperture gathers significantly more light than standard finder scopes, revealing the fainter guide stars needed to navigate complex regions of the sky toward your chosen deep-sky object.
The 50mm objective is a significant step up from smaller, standard finders, capable of finding most objects you are likely to search for. It gathers enough light to reveal dimmer stars essential for navigating to faint galaxies and nebulae, providing a bright image that makes star-hopping intuitive. With fully coated optics and integrated crosshairs, you can precisely center your target before switching to the main eyepiece.
Designed for convenience and stability, the finder mounts via a dovetail shoe for rapid attachment and removal from your telescope tube, which is especially useful for transportation. This system ensures your finder's alignment is maintained session after session. The mount itself features sprung-loaded adjustment screws, which hold collimation firmly while allowing for smooth, precise corrections.
Orion Optics UK offers this finder in two ergonomic designs to suit different observing styles. This straight-through version is ideal for quickly pointing your telescope toward a target by sighting directly along the main tube, a method many observers find fast and intuitive. The alternative angled finder (available separately) offers a more comfortable viewing position when objects are high overhead, reducing neck strain.
The 50mm aperture gathers substantially more light than typical 30mm or smaller finders. This results in a brighter image and makes fainter stars visible, which are often crucial for accurately star-hopping to deep-sky objects like nebulae and galaxies.
The finder uses a dovetail shoe for quick and secure attachment. This design allows you to remove the finder for transport and reattach it without losing your alignment. The sprung-loaded adjustment screws provide firm tension, preventing the alignment from shifting during use.
Yes. While GoTo is convenient, many astronomers prefer the hands-on experience of manually finding objects. A high-quality 50mm finder also serves as an excellent backup if your GoTo system has alignment issues or power failure, and it's perfect for quick, casual observations without a full alignment procedure.
The straight-through design allows you to sight directly along the telescope's main tube, making coarse aiming very intuitive. You can quickly point the scope to the general area of the sky and then use the finder for fine-tuning, a process many observers find faster than using an angled finder.
With an 8-inch Dobsonian, you would first point the tube towards the constellation Cassiopeia. The 50mm finder's wide, bright field of view would then allow you to easily see the guide stars needed to hop from Mirach (Beta Andromedae) upwards to find the faint, extended smudge of M31 and its satellite galaxies, something a smaller finder might struggle with.
The Ring Nebula (M57) is located between the two bottom stars of Lyra's parallelogram, Sulafat and Sheliak. The 50mm aperture of this finder is powerful enough to show these two bright stars and the fainter stars of the parallelogram clearly, allowing you to place the crosshairs precisely midway between them to locate the nebula's position.
| Model | AG12 |
| Aperture | 50mm |
| Type | Straight-Through Finder |
| Optics | Fully Coated |
| Reticle | Crosshairs |
| Mounting | Dovetail Shoe with Sprung-Loaded Adjustment Screws |
This product includes the finder scope and its integrated mounting bracket only. The corresponding dovetail base that attaches to the telescope is sold separately.