ZWO FF80 APO Astronomical Telescope User Manual

: June 1, 2024
: ZWO

Table of Contents

ZWO FF80 APO Astronomical Telescope
Instructions for use
Items in FF80 APO Packaging
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Download This Manual (PDF format)

ZWO FF80 APO Astronomical Telescope

Instructions for use

The FF80 APO is a refractive astrograph with the powerful flatfield optical design which saves you from the expensive cost of a field flattener. It eliminates the trouble of calculating the back focus distance of the flattener and connecting various accessories to achieve that distance. You can just connect any possible accessories you need as long as the target is focused. This makes the whole setting up process much more convenient, and saves your time, allowing you to pay more attention to the image shooting itself. It will also be an ideal telescope if you want to do visual astronomy. Directly connect the star diagonal to the eyepieces, you’ll see focusing is such an easy thing then. Planetary observation in high magnification is also piece of cake!

FF80 APO inherits the optical design of the FF- family, adopting a 3+1 quadruplet lens structure which contains two pieces of ED glass that can effectively reduce chromatic aberration and enhance clarity and sharpness. It’s worth mentioning that all astrographs from FF- family come with an integrated lens combination rather than simply placing three major lenses and a corrector together in a line. In another word, the whole optical system cannot solely perform without any piece of these lenses. This structure design leads to a more rational lens arrangement, better vignette control and superior image quality.

At the first glance, ZWO FF80 APO is much more compact. FF80 APO is 450mm in length and gross weight 4.7kg. So if your equatorial mount is not capable of holding heavy telescopes, or if you are quite tired of carrying a bulky long focal-ratio telescope around, then FF80 APO may be a great option.

In terms of the optical design, FF80 APO is 80mm in its aperture diameter and 600mm in focal length. Thus its focal ratio is f/7.5. It’ s actually a medium focal ratio telescope compared with those f/4 and f/5 short focal ratios or f/10 and f/11 long focal ratios. So FF80 APO is a compact halfway house.

The traditional long-focal-ratio astrographs are used only for observation due to the troublesome accessory connection. And those short-fo-cal-ratio astrographs consistently suffer a lot from chromatic or spherical aberrations. As a great mixture, FF80 APO is equipped with a 4-piece adapter, convenient for users to connect different types of accessories. So it’s a great helper in astrophotography. Besides, its special lens deign and powerful flatfield capacity make a crucial contribution to the high-quality imaging results, greatly reducing the impact of spherical and chromatic aberrations.

FF80 APO is also a novice-friendly device. Keep in mind that the distance from the base of M68 X 1 to the focal plane is 155mm, and you can literally attach any accessories within this limit. You don’t have to calculate your back focus distance which effectively simplifies the operation.

ZWO FF80 APO is a cost-effective refractor. It boasts special and fantastic vantages in both mechanical and optical design.

As an f/7.5 refractor, it can function well by virtue of its flatfield ability and rigorous optical performance.

Aperture size:80mm
Focal length: 600mm
Focal ratio:f/7.5
Objective lens: Quadruplet air-spaced APO (including two ED glasses)
Image circle: 44mm

Maximum accessory connection (with the focuser fully retreated):

Imaging mode:
115mm (from the base of M48 X 0.75 male thread)
135mm (from the base of M54 X 0.75 male thread)
155mm (from the base of M68 X 1male thread)
168.5mm (from the base of M76 X 1 male thread)
Observing mode:
148mm (from the end of 2″ eyepiece holder)

Total length: