Explore Scientific 152mm f/8 FCD-1 ED Triplet Refractor, Carbon Fiber, 2.5" Hex Rack And Pinion Focuser

This big and optically excellent 152mm (6") Explore Scientific air-spaced ED triplet apochromatic refractor has a carbon fiber body and a 2.5" Hex rack and pinion focuser. It is superb for visual observing and long-exposure DSLR and CCD imaging.

The 6" (152mm) aperture Explore Scientific ES152CF with 3" HEX focuser uses a premium ED glass element and state-of-the-art optical multicoatings in its apochromatic air-spaced ED triplet optics. The result is visual and photographic images that are essentially free of the annoying halo of unfocused violet light (chromatic aberration) that mars the view of bright stars and solar system objects in lesser scopes, despite the scope's large aperture, and even at very high magnifications.

The 152mm FCD-1 Explore Scientific triplet optics are even more appealing when you consider that this Explore Scientific apo is loaded with features other manufacturers charge extra for (or don't even have available) - such as a 3" focuser, an illuminated 8 x 50mm right-angle finderscope with erect right-reading images, a 2" dielectric star diagonal with 1.25" and 2" compression ring accessory holders, and a deluxe rolling carrying case.

The body and dew shield of this 152mm Explore Scientific are made of high strength, low weight, low thermal expansion carbon fiber. This keeps the scope sharply focused as the ambient temperature changes during critical long-exposure CCD imaging.

This version of the Explore Scientific ES152CF is a natural on an equatorial mount as the heart of your observing system. In addition to it's superb visual images, it's an excellent astrograph for both serious wide field deep space imaging and crisp solar system imaging.

Features of this Telescope . . .

ED triplet refractor optics: 152mm (6") aperture, 1216mm focal length, f/8 focal ratio three-lens air-spaced optical system. The optics use a center lens element of Hoya FCD1 (Dense Fluor Crown) glass, the Hoya equivalent of FPL-51 ED (Extra-low Dispersion) glass. This ED element produces superior sharpness and color correction by essentially eliminating chromatic aberration, the "false" color fringing seen around bright objects when light rays pass through standard crown-and-flint doublet objectives, particularly those with apertures in the 152mm class. The result is to reduce spurious color halos and fringing to vanishingly low levels for both imaging and visual use.

Fully multicoated optics: The triplet objective lens of the ES152CF has EMD™ (Enhanced Multilayer Deposition) antireflection multicoatings on all air-to-glass surfaces for high light transmission, minimal light scatter, and excellent contrast.

Internal light baffles: Contrast-enhancing internal light baffles and a specially darkened tube interior provide dark sky backgrounds and high terrestrial contrast.

Collimatable optics: One of the bonuses of owning a refractor is that, compared to standard reflector telescopes, they almost never require realigning of the optics (collimation). However, any air-spaced refractor telescope may require optical recentering if the lens elements are knocked out of alignment by a heavy blow during shipping or use. Removing the dew shield will give you access to the lens centering screws in the sides of the lens cell, which you can then adjust yourself by referring to the supplied instructions. You can also send your scope to Explore Scientific's Service Center for precision alignment. A standard service charge applies for factory realignment.

Carbon fiber body: The body and dew shield of the 152mm Explore Scientific are made of woven carbon fiber fabric, encapsulated in epoxy. Carbon fiber, the same material used to fabricate much of the fuselage and wings of the new Boeing 787 Dreamliner passenger jet, has a high strength-to-weight ratio to keep the scope almost 20% lighter than comparable aperture aluminum-body scopes. In addition, it has low thermal expansion characteristics when subjected to temperature variations. This helps to keep the instrument sharply focused as the ambient temperature changes, which is particularly important during critical long-exposure CCD imaging.

Dew shield: The supplied removable carbon fiber dew shield slows the formation of dew on the lens in cold weather to extend your undisturbed observing time. It also improves the contrast, similar to the effect of the lens shade on a camera lens, when there is excessive ambient light at night, such as a neighbor's backyard security light. A slip-on metal dust cap for the dew shield is standard.

Dual speed 2.5" HEX rack-and-pinion focuser: This version of the ES152CF uses a heavy-duty 2.5" rack-and-pinion focuser from JOC (Junghua Optical Company, the parent company of Explore Scientific). This 2.5" JOC has dual-speed focusing. There are two coarse focusing knobs. The right knob also has a smaller concentric knob with a 10:1 fine focusing ratio. This provides very precise image control during high magnification visual observing and critical DSLR or CCD imaging. The large focus knobs have ribbed gripping surfaces so they are easy to operate, even while wearing gloves or mittens in cold weather.

The focuser can be rotated 360° for the best photographic composition without affecting the focus, which is locked in place with a large brass knob on the top of the focuser. Three large brass knobs lock the focuser at any desired rotational orientation. The focuser drawtube has a scale marked on both sides in centimeters and 1mm increments. This lets you note individual focuser positions for easy return to the correct focus when switching between visual use and photography. A knob underneath the focuser lets you adjust the tension on the built-in drawtube brake to accommodate varying eyepiece/photo accessory loads.

2" dielectric star diagonal and compression ring eyepiece holders: The supplied standard equipment 2" mirror star diagonal of the ES152CF slips into the 2.5" focuser drawtube. The 2" diagonal has 99% reflectivity dielectric mirror coatings for high light transmission. The star diagonal uses a non-marring soft brass compression ring to hold 2" eyepieces in place. The compression ring won't scratch the barrel of your 2" eyepieces as an ordinary thumbscrew can. A supplied 1.25" accessory adapter slips into the 2" diagonal to let you use 1.25" eyepieces in the 2" diagonal.

Mounting rings and dovetail: The ES152CF has dual split mounting rings mounted on a Losmandy-style "D-plate" dovetail that fits the Losmandy-style dovetail slot on the head of many of the most popular heavy duty German equatorial mounts. Such mounts include the Celestron CGEM DX and CGE Pro, the iOptron iEQ45, the Losmandy G11 and HGM Titan, and the Software Bisque Paramount MX go-to equatorial mounts, among others. A spacer/stabilizing bar on the top of the rings provides a carrying handle that makes it easy to transport the optical tube and install it on your equatorial mount.

Extended lifetime warranty: This individually serial numbered Explore Scientific telescope is backed by a limited one year warranty, which will be extended to an Explore Scientific transferable lifetime limited warranty when its warranty card is registered with Explore Scientific within 60 days of purchase.