Excited to be returning to practice astronomy, I decided to compile below some things I learned about binoculars during this time. Some go completely against what I imagined when I started to practice astronomy. I hope that helps those who want to buy a pair of binoculars.
The first thing you need to know is about binoculars that are sold from street dealers in Brazil for US$10 to US$20. They are pure garbage, made with plastic lenses. Comparing the quality of these binoculars with something decent is a joke. In many cases you see better without them than with. If you want to buy a good pair of binoculars in Brazil, You will have to agreed paying a couple hundred dollars. Do not commit the crime of giving a US$10 binoculars to his son, much more if he is interested in astronomy. Unless you just want him to forget this practice.
The harsh reality is that binoculars have absurd prices in Brazil. A US$150 model found in a Brazilian store, costs about thirty dollars in the United States. One that costs US$1000 here, costs about US$ 300 there. Moral: products seen as high level here, as the cheapest binoculars from Celestron or Orion, are seen as toys in the United States, while the products seen by them as quality products, to us are products of the English aristocracy.
It is when you look at the night sky that you really find the quality optics of a binocular. Products that look perfect when you're looking at a landscape during the day will reveal its shortcomings when are pointed toward a planet or star in the night: the picture does not come together, chromatic aberration spreads, reflexes pollute the image, the stars deform approaching the edge of the field of view. Even US$150 will present real problems when looking at the night sky and you'll understand why there are those that cost about 2000 dollars.
Something that will make you confused, is finding that image increase is a totally different meaning than you imagined. The first thing you will hear from experienced practitioners when buying binoculars is to much increase is "very bad, and little increase is good." You will take longo to accept this, but will soon realize that a binocular with too much increase delivery very dark and absurdly blurred image, and a narrow field of vision, making it a great difficulty to find and watch what you want. You will find that the highest good increases are between 7 and 11 times. Above that you will need a very large and heavy binocular and a robust and high tripod (and both will be very expensive.
You will also find that, for astronomy, zoom is a nuisance that can undermine the quality and much observation, mainly to greatly reduce the size of the image field of view.
In the beginning you'll also hear about prisms and BaK4 BAK7 and will not understand the difference, the only thing I understood is that all the experienced say BK4 is best for those who want to use the binoculars for astronomy, sometimes without explaining the law because. When you look at a star with a binocular with BK7 prism and see how it deforms when approaching the edge of the image, you'll understand the difference.
A very common type of nonsense you'll find on sites like "Mercado Livre" are things like "Binocular with a range of 1km." It does not exist and who describes his binoculars so normally do not have the slightest knowledge about the product they are selling. Binocular is a product made by lenses. What they do is give more power to your eyes without changing its basic characteristics. As your eyes, binoculars can see to infinity if there is nothing in front of the opaque object.
If you are in order to find a good pair of binoculars on the Internet and live in Brazil, watch for addresses of two of Brazil's most respected sites:
www.astroshop.com.br
- BK4 prisms.
- increased from 7 to 11 times.
- opening between 50 and 63mm
- maximum weight of three pounds.
- Fully Multi-Coated Lenses
- Visual comfort above 11 mm if you do not wear glasses and about 20mm if you use.
- Price between US$100 and US$200 (in Brazil).
Great post!!! Thank you for sharing these things and that are very useful to us..While searching I had come across one site that provides binocular telescope etc & I must say it provides best quality products in very amazing prices...Just have a look http://www.bosmaoptics.com/
ReplyDelete