$Apertura 102mm FCD-100 Doublet APO Classical Refractor — image 1$

Apertura

Apertura 102mm FCD-100 Doublet APO Classical Refractor

A long, classical f/11 FCD-100 doublet built for one thing and doing it superbly: high-contrast, color-clean views of the Moon, planets and double stars. A visual refractor purist's tube, not a wide-field imager.

78/ 100

Polaris Score

# of 101 refractor

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Aperture

102mm

Focal Length

1122mm

Focal Ratio

f/11

Mount Type

None (OTA only)

Optical Design

ED Doublet Refractor

Weight

4.8 kg

From$1,399.95

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Where to buy

High Point ScientificBest price$1,399.95→

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What it's built forOpen these in the simulator →

This telescope lives for the planets.

An f/11 focal length built to magnify. Where fast scopes sweep wide, this one holds a single planet rock-steady at high power — a telescope for the patient observer on a steady night.

Sweet spot 80–130×Loves steady seeing

The view people remember

Saturn, with its rings tilted wide.

The one you call people outside to see — the rings standing clear of the planet, the Cassini Division a clean black line drawn around them.

See Saturn through this telescope →

Where else it shines

Never gets old

The Moon

Crisp crater rims and fine surface texture, ridges visible inside maria

Open view →

Also excellent on

Jupiter

Recognizable disk with subtle markings under steady seeing

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Within reach

Orion Nebula

Stronger structure — embedded stars plus dark lanes within the core

Open view →

Easy first target

The Pleiades

Rich field — fainter members fill out the cluster

Open view →

✦

Wide-field nebulae belong to another kind of telescope. This one trades width for reach.

01What it's good at

What it's best at — and the trade-offs.

Best at

✓The long f/11 focal ratio and FCD-100 ED glass give near-apo color correction, so bright stars and planet limbs stay clean and high-contrast.

✓102 mm at 1,122 mm delivers sharp, steady high-power views of lunar detail, planetary features and tight double stars.

✓A sealed refractor needs no collimation and holds its optics stable for years, with almost no cool-down fuss.

✓The dual-speed 2-inch rack-and-pinion focuser gives the fine control high magnification demands.

Trade-offs

!At f/11 it is slow, which rules out practical deep-sky astrophotography.

!The 1,122 mm long tube needs a sturdy mount and has real moment arm, so it is not a light travel scope.

!The narrow true field won't frame large objects like the Pleiades or the full Andromeda.

!Sold as an optical tube, so budget for a mount, diagonal and eyepieces.

02In plain English

What These Numbers Mean

Aperture

102 mm

Four inches of unobstructed glass gathers roughly 210 times more light than your eye. That is enough for crisp lunar detail, the belts of Jupiter, Saturn's rings with the Cassini division on steady nights, and the brighter Messier clusters and nebulae. Faint galaxies stay small and grey; this scope trades reach for image quality.

Focal length

1122 mm

Long for a 4-inch refractor, which is exactly the point. It reaches 100x to 200x with ordinary eyepieces and no Barlow, so the Moon, planets and double stars sit naturally in the sweet spot. Wide fields are not its job: a 30 mm eyepiece still only gives about 37x.

Focal ratio

f/11

A slow focal ratio keeps colour error and coma essentially invisible and makes even inexpensive eyepieces perform well. The cost is a narrow field of view and dim, long exposures if you point it at deep-sky imaging. Treat it as a visual and planetary instrument first.

Optical design

FCD-100 ED doublet

Two elements with an FCD-100 ED front element, in a classical long-focus layout. At f/11 the doublet has an easy job correcting colour, so you get near-apochromatic sharpness for doublet money. A triplet buys you the same correction at a much faster ratio and a much higher price.

Weight

4.8 kg tube

About 10.5 lb of tube, but a long one. It is a one-hand carry to the mount, though the length gives it more leverage than the number suggests, so the mount matters more than the mass.

Mount

OTA only

No mount is included, and this tube's length punishes an undersized one. Budget for a solid alt-az or a mid-size equatorial rated well above 5 kg if you want steady views at 200x.

02The Polaris Score

How it scores, and why.

78/ 100

Apertura 102mm FCD-100 Doublet APO Classical Refractor

# of 101 refractor

Performance

Ease of use

Portability

Upgrade potential

Polaris weighs optical capability, how easy the scope is to live with, how portable it is, and how far it takes you before you outgrow it — not list price or brand.

03Who it's for