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Explore Scientific 2" 3x Focal Extender - FE03-020

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SKU: EXS-FE03-020

Explore Scientific 3x Focal Extender - 2"

Focal extenders function exactly as you would expect, extending the effective focal length of the lens in order to generate higher magnifications for imaging and visual applications.

Even though focal extenders are similar to Barlows or tele-negative lenses, there is one crucial difference you'll want to pay attention to, particularly if you want to use this Explore Scientific Focal Extender for imaging and astrophotography.

By using a standard Barlow or tele-negative lens to enhance your optical system's magnification, the results you get will be reliant upon the placement of the Barlow in the optical chain. For example, if you place a 2X Barlow Lens in front of your diagonal instead of behind it (Barlow-Diagonal-Eyepiece as opposed to Diagonal-Barlow-Eyepiece), you won't achieve 2X magnifications in both configurations. Magnification differs with placement. However, with this Explore Scientific 3X Focal Extender, magnification is consistent even when the distance is altered. It can be placed anywhere in the optical chain between an eyepiece or a camera. 3X magnification means you will get 3X magnification.

When it comes to imaging, this is a critical difference, because you may want to introduce an accessory like a flip mirror or filter wheel in between the Focal Extender and a CCD camera, which would increase the distance to the focused image. This difference in design allows users to rest easy, whether they are pumping up the magnification of a lower power eyepiece for visual observations or using their Explore Focal Extender in imaging applications.

Explore Scientific Focal Extender Highlights

More Magnification Choices without Sacrificing Eye Relief

A quality Focal Extender adds some genuine flexibility to your telescope accessory roster. First, it enables the magnification increase of any eyepiece you already own that has a barrel size identical to that of the focal extender. In other words, 3 eyepieces give you 6 magnification options with the addition of a focal extender. Second, lower magnification eyepieces usually have better eye relief than higher power models. By using a focal extender in lieu of a higher magnification eyepiece, you get to enjoy the comfortable eye relief of the lower power eyepiece. For observers who wear eyeglasses, or for those with fast telescopes who can really push high magnification eyepieces, this can be a significant perk.

Optimized Optical Design

Explore Focal Extenders are optimized through each design, fabrication, and testing process to produce high contrast, high resolution images.

Durable Coatings & Finishing Touches

All four elements of Explore Scientific Focal Extenders are fully multi-coated using Explore EMD enhanced coatings for bright, sharp images. In addition, every element features blackened edges to minimize internal reflections and increase contrast.

Tapered Barrel For Extra Security

The insert barrel of each extender is double-tapered to allow smooth insertion to, and removal from, a telescope's eyepiece holder, focuser or diagonal. However, the wide dimension of the taper helps prevent the focal extender from falling out of the telescope should the set-screw holding it in place become loose. The barrel is threaded to accept 2" filters.

Warranty Information:

Limited Warranty is one year, which converts to the Explore STAR Transferable Extended Life of the Product Warranty when product is registered on within 60 days of purchase.