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Celestron Omni Series 1.25-inch Eyepiece 4mm
The Celestron Omni 4mm 1.25” Plössl eyepiece delivers a 50° field of view, multi-coated optics, and blackened lens edges for sharp, high-contrast views of the Moon, planets, and some deep-sky objects.
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The Celestron Omni 4mm eyepiece delivers a 50º apparent field of view, making it ideal for detailed observations of the Moon, planets, and deep-sky objects. Designed with a four-element Plössl optical system, it features multi-coated lenses for enhanced light transmission and sharp, high-contrast views.
The eyepiece’s aluminum body undergoes a two-step anodizing process, giving it a matte finish that minimises reflections. Blackened lens edges further reduce internal glare for improved image quality. A foldable rubber eyecup provides added comfort and helps block stray light, whether used with or without eyeglasses. The standard 1.25” barrel is threaded to accommodate most filters for added versatility.
Full Specifications
| Focal Length | 4mm (0.16") |
| Apparent Field of View | 50° |
| Eye Relief | 6mm (0.24") |
| Optical Coatings | Multi layered high transmission |
| Number of Lens Elements | 4 |
| Barrel Size | 32mm (1.25") |
| Parfocal Eyepieces | No |
| Threaded For Filters | Yes, 1.25" |
| Warranty | Celestron 2 Year Warranty |
Recommended Accessories
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Lens Cleaning Pen Keep your eyepieces in check with a 3-in-1 lens cleaning pen! |
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saxon Optical Lens Cleaning Kit Keep your binoculars and lenses in top shape by keeping it free from dust and degree and cleaned regularly! |
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About Celestron
Celestron was founded by Tom Johnson whose first telescope design was a simple 6-inch reflector, built for his young son. He gradually progressed to making larger scopes in more sophisticated designs. Today, the Celestron company is an industry leader in designing and manufacturing optical equipment including telescopes (computerised and non-computerised), binoculars, spotting scopes and its accompanying accessories. Celestron's legacy spans 50 years, and has grown to enjoy recognition from amateurs to serious astronomers globally. The company seeks to remain innovative by growing its product offerings, while supporting science education around the world.
Product Code: 93316
Q1. How do I choose the right eyepiece for an object?
Generally, choose a low-power eyepieces (e.g., 25–40mm) for wide views of star clusters or to locate objects. Mid-range (10–20mm) is great for planets and the Moon. High-power eyepieces (below 10mm) are for close-up detail but may be affected by atmospheric conditions. These numbers may require an additional barlow lens for low focal length telescopes.
Tip! Use our Telescope Field of View Calculator to work out the relative field of view of an eyepiece through a telescope.
Q2. How do I clean telescope eyepieces?
Great question! Avoid cleaning unless necessary. If you notice smudges or dust affecting your view, blow off loose dust with a soft air blower. Use a lens brush for stuck particles. For smudges, use a few drops of lens cleaning fluid on a microfibre cloth or lens tissue, gently wiping in a circular motion from the centre outward. We recommend the saxon Optical Lens Cleaning Kit.
Q3. How should I store eyepieces when not in use?
Keep eyepieces in a protective case or pouch to prevent dust, scratches, and moisture. Always replace caps after use, and avoid storing them in humid environments to prevent fungal growth.
Q4. Can I use filters with eyepieces?
Yes. Most 1.25" and 2" eyepieces accept threaded filters at the base. Screw them on gently and make sure they are clean and scratch-free before use.