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Telescopes > William Optics > William Optics Apochromatic refractor AP 81/535 GTF81 OTA
Product no.: 43894

Apochromatic refractor AP 81/535 GTF81 OTA

$ 1,730.00 incl. VAT, plus shipping costs
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Product description

The stunning new William Optics GTF 81APO is the new jewel of the apochromatic refractor world. From the pristine white finish on the CNC to the elegant red beauty which has more than just good looks... New GTF 81 features total 5-element in 2 groups design by using high-quality FPL-53 extra-low dispersion glass that reduces any secondary spectrum to an unbelievable degree,the second group of ED element (flat field corrector) is correcting the edge of flatness to the best quality (cover up to 40mm of image circle).


Optically Unbeatable

  • Five element in two groups air-spaced objective (FPL-53) in adjustable CNC machined ultra high precision lens cell.
  • Extremely sharp.
  • Excellent color correction.
  • Each lens is Fully Multi-Coated with a special super-high transmission coating (STM Coating) on all surfaces.
  • This F/5.9 lens is ideal for astrophotography.

2.5" R&P DDG Focuser

  • The Digital Display Gauge - DDG - allows you to take precise focusing readings down to two decimals precision instantly.
  • Extra-smooth 360 deg. rotatable 2.5" Rack & Pinion focuser with 1:10 dual speed: a treat to use during astrophotography. No image shifting!
  • Comes with two locking screws on angled positions for heavy load applications.
  • Large aluminum knob with installed thermometer and aluminum protection cover.

Attention to Details

  • 2" & 1.25" adapter included in the price.
  • Anti-marring brass compression rings
  • Carry handle with V-shape night glowing illuminator.
  • Guiding scope are optional.
  • 90mm mounting rings are optional.
  • Though you will never need it, you have a 2-year warranty from WO, and the certainty that we will be there to assist you even beyond that, if you need!

It not only matters which telescope you buy but also where you buy it. Our additional services:

  • We are a leading telescope dealer and know the devices we sell. Our customer service team will gladly help you after your purchase if you have problems with assembly or operation.
  • We provide a copy of the 80-page Telescope ABC beginners handbook with every telescope.
  • We also provide an edition of the exciting astronomy magazine, “Sterne und Weltraum” with each telescope.

Specifications

Optics


Type
Refractor
Aperture (mm)
81
Focal length (mm)
535
Aperture ratio (f/)
6,6
Resolving capacity
1,42
Limit value (mag)
11,3
Light gathering capacity
130
Max. useful magnification
162
Tube weight (kg)
3,7
Tube length (mm)
484
tube diameter (mm)
90

Focuser


Gear reduction
1:10 Fine movement
Connection ( to eyepiece)
2

Included accessories


Dew Shield
yes
Corrector
Flattener
Camera adaptor
T2 (M42 x 0,75)

Area of application


Astrophotography
yes

Recommended for


Beginners
no
Advanced
yes

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*All prices include VAT plus shipping costs.

William Optics Apochromatic refractor AP 81/535 GTF81 OTA
William Optics Apochromatic refractor AP 81/535 GTF81 OTA
William Optics Apochromatic refractor AP 81/535 GTF81 OTA
William Optics Apochromatic refractor AP 81/535 GTF81 OTA

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