Excellent quality amateur astronomy telescopes are available at a lower price than ever before. These amazing devices enable the user to view expansive star fields, glowing nebulae, the remnants of exploded stars, and galaxies so distant that their light left on its journey to us millions of years ago.
The wide differences in magnification needed to view such varied objects are effected by the use of removable eyepieces. A good quality eyepiece can give enable breathtaking views of the night sky. A poor quality eyepiece on the other hand can ruin even an expensive telescope's view.
Historically, all eyepieces gave narrow angle views (like looking through a tube), but a revolution about 20 years ago saw companies introduce wide angle eyepieces onto the market. These eyepieces came at a price, however, up to £400 each!
Recently, Meade has introduced its own ranges of wide angle eyepieces, the 5000 series.
The Meade 5000 series Super Wide Angle 20mm is one of that range. The 20mm eyepiece is a chunky piece of kit. Weighing in at 254g, it consists of six glass elements packed into a bulky frame (with such a large eyepiece, it's possible that it may upset the balance of a smaller telescope, so check for this when fitting the eyepiece to the scope).
The 20mm has a field of view of 68 degrees. This is far greater than older designs which were often less than 50 degrees and is closer to the eye's natural field of view.
Magnification of a telescope/eyepiece combination is calculated by dividing the telescope's focal length by the eyepiece's. My eight inch reflector has a focal length of 1000mm so using the 20mm gives a magnification of 1000/20 = 50 times.
This low magnification is perfect for viewing the larger astronomical objects in the night sky, as well as the star fields of the Milky Way.
The eye relief of the eyepiece is very generous (meaning the user does not have to put the eye right over the lens) and allows spectacle wearers to use the telescope whilst wearing their glasses.
Using the eyepiece, the first thing that will be noticed is the wide angle view; so wide that it can be necessary to look around to get a good look at the object of interest. This gives the user a sense of viewing directly, rather than using a telescope, and brings the night sky wonders directly to the viewer's eye.
Next it will be noticed how sharp the view is. Many eyepieces have distortions that smear the view at the outer edges of the field. The 20mm Meade is sharp from edge to edge; amazing considering the wide field of view. Again, this enhances the viewing experience.
What's not apparent is any chromatic aberration. Poorer quality lenses show colour fringes at high contrast edges. These are absent from the 20mm.
Using the 20mm gives, with large, diffuse objects, the chance to get a complete view of sights that would be only partially within the view of a higher magnification eyepiece.
The famous 'double cluster' in Perseus is a tremendous sight in the 20mm. The whole of the double cluster fits in the field of view. Set against a velvet sky, the tiny sparkles of the hundreds of individual stars making up the clusters shine with diamond, ruby and sapphire lights; a twin jewel box shining down from the heavens.
Perhaps even more impressive is the view of the Pleiades. This dazzling cluster is visible to the naked eye as a grouping of six or seven stars. Although with the 20mm, the whole cluster spills over the field of view, the brightest stars fill the frame. Suddenly, the viewer sees a dazzling sight. Over 50 blazing blue points of light, young, massive stars many times more luminous than our sun glare down through the eyepiece giving an awesome experience on a cold winter's night.
This eyepiece has then, a lot of attractive features; wide angle, edge to edge sharpness, with no chromatic aberration apparent. There is one less than impressive aspect, however, the price. Although these eyepieces are less costly than the high end items, they're not cheap. The 20mm cost me £169 from Telescope House. This is expensive, but for a high quality eyepiece, is not unexpected. If you want a high quality, wide angle eyepiece, then the Meade Super Wide Angle 20mm is highly recommended.