William Optics GTF81 5-Element 81mm APO Imaging Refractor Telescope
The stunning new William Optics GTF81 APO Refractor telescope is the new jewel of the apochromatic refractor world. From the pristine white finish on the CNC machined tube assembly to its elegant red highlights, it sports a beauty which is more than just good looks... The new GTF81 features 5-elements in 2 groups designed using high-quality FPL-53 extra-low dispersion glass that reduces any secondary spectrum to an unbelievable degree. The second group of ED elements (which is a field flattener) provides an image field flatness to the maximum quality (covering up to a 40mm diameter image circle).
A 2" & a 1.25" adapter are included in the price of this GTF81 APO Refractor Telescope from William Optics. It sports anti-marring brass compression rings to hold your eyepieces or accessories. The scope includes a carrying handle with a V-shaped night glowing illuminator. A Guiding Scope is an optional accessory as are 90mm mounting rings.
This telescope has a 2-year warranty from William Optics.
The WO GTF81 5-Element 81mm APO Imaging Refractor Telescope includes a 2" rack & pinion (R&P) focuser which will accept an optional Digital Display Gauge (DDG). The DDG (which is an option) allows you to take precise focusing readings down to two decimals. Extra-smooth 360 deg. rotatable 2.0" R&P focuser has a 1:10 dual speed: a treat to use during astrophotography. It prevents image shifting! Comes with two locking screws on angled positions for heavy load applications. It has a large aluminum knob with installed thermometer and aluminum protection cover.
|Focal Length||535 mm|
|Objective Type||Five element with FPL-53 Air Spaced (2 groups), Fully Multi-Coated, STM coatings|
|Resolving Power||1.43 seconds of arc|
2" 360° Rotating Camera-angle Adjuster, 1:10 fine focus Focuser Travel Length 3.15" (80mm)
|1.25" Adapter||2" Brass Compression Rings|
|Field Stops||knife edge Baffles|
|Tube Length||440mm Fully Retracted
484mm Fully Extended
Objective Lens Surface Finish Specifications: