ESPRIT 100ED APO OTA Features
- Air Spaced 100mm Apochromatic Triplet
- FPL-53 extra low dispersion glass
- Zero detectable colour fringing even on bright objects
- Diffraction limited optics
- Fully multi coated lenses
- 3″ CNC machined 11:1 dual speed linear power focuser – rotatable
- Indexed focuser tube
- Knife-edge baffled system to enhance contrast
5 year manufacturer warranty (not transferable).
ESPRIT 100ED APO OTA Description
ESPRIT 100ED APO OTA
The Sky-Watcher 100mm Esprit 100ED Triplet APO Refractor is a professional instrument for the most demanding and exacting astro-photographers. The air spaced apochromatic triplet lenses use the remarkable Ohara FPL-53 ED (extra low dispersion) glass, with exceptional colour correction over the entire visible spectrum there is no chromatic aberration even on bright objects! Knife edge baffles reduce internal reflections and increase contrast, helping to bring out faint structure in deep sky objects.
A 2-element field flattener is included to iron out the natural off-axis astigmatism and field curvature of the objective lens, leaving a fully corrected 42mm field of view. The Sky-Watcher exclusive Helinear Track 11:1 dual speed focuser is rock solid with zero image shift and a 3″ barrel to avoid vignetting. Designed with photography in mind, it sits on two tracks above and below the barrel to prevent flexure with a heavy camera attached, and is fully rotatable to perfectly frame a target on the sensor.
In The Box:
- 100/550 Apochromatic Refractor
- Fixed Dew Shield
- Field Flattener with M48 Thread
- T2 Canon Camera Adapter
- 2″ Dielectric Star Diagonal
- 9×50 Right Angled Erect Image Diagonal
- D Style dovetail Bar
- 2″ to 1.25″ Eyepiece Adaptor
- Aluminium Foam-Lined Case
Optical Design
Airspaced Apochromatic Triplet
The optical design of a telescope is a feature that defines what sort of observing the telescope is suitable for.
Optical Diameter
100mm
The aperture (diameter) of a telescope’s main lens or mirror. This describes how much light a telescope can grasp.
Focal Length
550mm
The distance that the light has to travel between the aperture and the focal point. A smaller focal lengths will deliver a wider field of view.
Focuser
3″ Crayford dual speed with 2″ and 1.25″ adaptor
Wider focusers allow for a wider field of view.
F/Ratio
f/5.5
The relationship between the focal length and the aperture, larger f/numbers imply higher magnification.
Highest Practical Power
200x
Exceeding the Highest Practical Power will result in a fuzzy image.
Light Gathering Power
204
How much brighter things will appear than what the human eye can see.
Tube Weight
6.15kg
You may need a counterweight to prevent your telescope from rotating downwards due to gravity.
Corrected Field Diameter
40mm
the maximum diameter of the circular area in the eyepiece where the image remains sharp and clear.
Visual Back Focus
465mm
The distance from the eyepiece to the point where the light rays converge to form a focused image.
Resolving Power
1.20″
The ability to clearly distinguish between two points whose separation is less than the smallest angle that your eye can resolve.
Stellar Limit Magnitude
12.0
The magnitude of the faintest object visible under zero light pollution conditions.