An “APO doublet” is actually just an improved achromatic doublet (two-lens) design that utilizes higher quality glass (like extra-low dispersion or ED) and/or coatings (like Fluorite) to achieve performance closer to a true apochromatic triplet telescope. However, many manufacturers use the term “APO doublet,” which is why it is included here. Technically, a truly apochromatic (APO) design uses a three lens system to bring red, green, and blue light into focus on the same focal plane, which generally eliminates all chromatic aberration. Intermediate ┃ $$ - $$$ | Best for beginner astrophotographers Shop Achromatic Doublet Refractor Telescopes Lower cost scopes usually have a not very sturdy mount.Long focal ratio means galaxies and nebulae are harder to spot.With heavy chromatic aberration, views are only so-so.Easy-to-use and intuitive for beginner visual observers.Lightweight and compact for portability.The most affordable of any kind of telescope.However, achromatic doublets can be a solid starting point for amateurs looking to enter the hobby as they are the most inexpensive kind of telescope. In addition, doublets will generally have a longer focal ratio than higher-end refractors like triplets, which translates to more zoom but means some dim objects like galaxies may be too faint to spot. An apochromatic telescope will provide much better views and images.
This makes for less-than-ideal viewing and imaging, but still plenty good enough for most beginners. The two lenses can allow both red and blue light to reach the focal plane at the same time, but green and magenta light arrive separately, making for colored halos around brighter stars, planets, and the moon. By definition, an achromatic doublet uses two lenses to partially correct for chromatic aberration, or color fringing. These are some of the most common telescopes, and just about all beginner refractor telescopes will be an achromatic doublet design. A small, widefield refractor is the best choice for those looking to begin astrophotography beyond a camera lens.īeginner | $-$$ | Best for beginner visual observersĪn achromatic doublet is the most affordable and simplest kind of telescope. High-quality refractors, on the other hand, can provide some of the best views and images of any telescope design, but are the most expensive to produce. Cheap refractors are often poorly made and can suffer from heavy chromatic aberration, otherwise known as color fringing, where bright objects like stars and planets can have colored halos around them. Refractors are the simplest and most lightweight telescope design. Light enters through the front lens element, is refracted (bent) into focus by other lens elements, and exits through the rear of the telescope and into an eyepiece or camera.
Refractor vs reflector telescope series#
Refractors, much like camera lenses, use a series of glass lens elements to bring an image into focus.
0 kommentar(er)
