Accessories For Telescopes
Eyepieces and Filters
An eyepiece, or ocular lens, is a lens that you attach to the viewing end of your telescope. The objective, or primary, lens or mirror collects the light to create the image. The eyepiece is placed at the focal point of the telescope to magnify that image so you can see it. This magnification is provided by the focal length of the eyepiece itself. An eyepiece features the lens itself, the housing barrel, and maybe a filter or two.
Telescope filters adjust the contrast and brightness offered by telescopes. They can also add colors when needed for such things as reducing the glare of the sun. Filters are positioned between the eyepiece and the telescope’s main body.
Almost all telescopes come with 2 or 3 in a kit
You may asking yourself if you need to buy eyepieces and filters too, but you can rest assured that most telescopes come with 2 or 3 of the more commonly used ones in a kit. Most people won’t have to buy anything else. However, Optics Central has a fine selection of filters and eyepieces if you need them.
Barlow lenses are filter lenses that extend the effective focal length of your telescope. In other words, these lenses increase your telescope’s magnification. They are placed before your eyepiece and are rated by the magnification increase they provide. Most Barlow lenses come in 2x and 3x sizes, but there are a few adjustable lenses that use extensions tubes to increase magnification.
Plossl or symmetrical eyepieces are a special type of eyepiece consisting of two sets of lenses called doublets. These eyepieces increase the effective viewing angle of your telescope making them ideal for deep sky and planetary viewing. However, this comes at the cost of eye relief which is the viewing distance between the eyepiece and your eyes. Plossis have really short eye reliefs which means you must come up really close to them before you can see anything.
What Do I need for Astrophotography?
Astrophotography is one of those things that are easy to get in to but require a lifetime to master.
All you need is a camera
To get started, all you really need is to mount a camera to a tripod. That’s it. You can do a lot with this setup and it is the best way to learn the craft as it will let you figure out your preferred camera equipment before you start spending money on the more expensive telescopes.
Photography with your telescope
If you are planning to mount a camera onto your telescope, there are a few ways to do this. A compact camera can be mounted with a simple Universal Camera Adapter.
If you have an SLR, you will need a T-Ring and a T-Adapter. The T-Ring is a mount specific to the brand of your camera. So, if it’s a Nikon SLR, you will use a Nikon T-Ring.
|Saxon Variable Projection Camera T- Adapter 1.25"
|Universal Camera Adapter
Planispheres, moon and phase maps…
Planispheres are star charts that display what you can see for any given time and date. They are generally used to assist in identifying stars and constellations. Planispheres are analog equipment. They are basically two dials that rotate on a common pivot, and are useful when you don’t have access to a computer. Please note that planispheres are designed for specific latitudes. You need to know yours before you can get or build one of your own.