The ZWO FF107 Quadruplet Apochromatic is a refractive optical tube with a flatfield optical design. Users can avoid the annoyance of back focus calculation and spend more time getting high-quality images.

Users can attach any accessories they need without back focus calculation as long as the object being imaged is focused properly.

The ZWO FF107 Quadruplet Apochromatic Refractor optical tube is great for both imaging and visual observation! In addition to many imaging cameras, it can also accommodate and connect with diagonals, eyepieces, and other visual accessories. With high magnification eyepieces, terrestrial and celestial viewing of planets will be remarkable!

The ZWO FF107 Quadruplet Apochromatic is a refractive optical tube that comes with a flatfield optical design, which is highly efficient and saves the additional expense of purchasing a field flattener. With this feature, the user no longer needs to go through the hassle and time-consuming process of calculating the back focus distance of the flattener or connecting various accessories and spacers to obtain the proper distance. This also means that users can easily connect any necessary accessories as per their requirements. The imaging system is superb and highly convenient to use, as long as the celestial object is in focus.

The ZWO FF107 Quadruplet Apochromatic Refractor optical tube is not only suitable for imaging due to its optical characteristics, but it is also an excellent choice for visual observation. Its design allows diagonals and eyepieces to fit seamlessly, just like any other optical tube, generating a splendid view of planets with high magnification eyepieces. The rings of Saturn, Jupiter's clouds, and phases of Venus should be a breeze to view in detail! This makes it an ideal option for amateur astronomers looking to observe and photograph celestial objects as well as deep sky objects that are of smaller angular size and higher magnitude.

An important advantage to note in the ZWO FF107 Quadruplet Apochromatic OTA is its 44mm image circle, enough to accommodate a 35mm full-frame sensor. This is important because full-frame cameras have several advantages over crop sensors (APS-C) and smaller-sized sensors. First and foremost, they have superior light capture which especially if using a camera with a good full well capacity and Quantum Efficiency, comes in significant handy in terms of image resolution and brightness. Secondly, they also have a wider angle view of the object centered and thus excel better for wide field observing.