Optical Features Of Telescopes
The ability of a telescope to focus light is related to the optical features you use. Considerations to make when purchasing optical equipment – Aperture, Magnification, Focal Length, Focal ratio, Wave Number, and Resolution. If you purchase low quality merchandise, you won't be able to see what you are looking for as well.
The most important consideration is the Aperture. This is the ability to focus light and is related to the size of the lens or mirror that is used. In other words, the bigger the lens or mirror, the brighter the final image. The biggest telescope, however, is not always the best.
Magnification is dependent upon the lenses used and the distance to the eyepiece. A general rule of thumb to follow is 40-60x per 1 inch of aperture. Usually low magnification gives the best light.
Focal length is defined as the optical length of the telescope lens. Long focal lengths usually mean higher magnification. Don't mistake the length of the telescope for focal length though. Some compound telescopes light paths are folded and become longer in a short tube.
The focal ratio tells us about he brightness and width of the field of view. They are divided into three sections. F/10 or higher is good for viewing the moon, planets, or stars. F/8 is great for all around viewing. F/6 and lower is meant for viewing deep sky objects.
The wave number is also known as the wave error. It tells us how good the mirror or lens was ground to an almost perfect surface. The smaller the number, the better the lens or mirror. The minimum number that is acceptable is one fourth. The performance is in the accumulation of the numbers of each optical piece.
Resolution is the ability to find the details in the moon or a planet. It is dependent upon how well the telescope can separate two close objects. It also rests on the aperture and the observing conditions that are present.
Telescopes
Finding The Telescope That Meets Your Needs
Viewing Deep Sky Objects And Comets
Telescopes
... Jupiter's small satellite moons. They are usually in a straight line and appear as very bright stars. Given Jupiter's rapid rotation, you can view nearly all the planet in a single night. The simplest thing you can do is look at the stars. Sometimes, you may see a double-star. What looks like a single ...
Viewing The Night Sky With A Telescope
... using one before you buy. They also meet in the evenings so you can learn how to observe the night sky. It is truly fascinating to see the images with your own eyes instead of just looking at pictures on the web or in books. Telescopes are used for two reasons. One is to see fainter objects and the other ...
Telescope Advice For Beginners
... as the case may be. Look up the night sky without the aid of a telescope. Can you spot and name any constellations? Can you spot the moon or the planet Venus or Jupiter? If you can't do this, you might have some trouble spotting other heavenly objects. There are many magazines out there that follow astronomy ...
... an object as a far distance and enlarge it so you can see it clearly. Any magnification can be obtained by using different eyepieces depending on the object you are trying to view. Here is a simplified explanation. Obtain two magnifying glasses and a piece of paper. Hold one of the glasses between you ...
... Masking tape, Flashlight, Thin piece of paper, a pair of reading glass with low numbers, yardstick, and an assistant. Tape the reading glasses to the yardstick making sure one lens is out on the side. Place the flashlight on a stand about twelve feet away. Shine the light at the lens that is sticking ...