vxg@panda.UUCP (Vincent Gonzalez) (12/12/85)
I would like to thank all of you, who have commented on the use of
binoculars in night viewing of stars and comets. Having been convinced
that I should spend some funds on a binocular, opposed to a low price
telescope, my question now whould be: What magnification is best suited
for night viewing? I took a trip to a local camera shop and discovered
a variety of choices 7X50, 8X50, 10X50, 20X50, etc. A chart on their
wall stated that the 7X50 was a good choice for all around use and that
the 10X50 and 20X50 were best suited for "plane sighting", but not recom-
mended for nigh viewing. Hence, I am leaning toward the 7X50. What
will the more powerful glass do for me? What are their drawbacks?
Please send me mail with any help you can give. I will summaries for
the net if their is any interest.
Thanks, Vincent Gonzalez
UUCP: {decvax,linus,wjh12,mit-eddie,cbosgd,masscomp}!genrad!panda!vxg
MABELL: (617) 369-4400 x2353
USPS: GenRad, Inc., 300 Baker Ave., Concord Ma. 01742rdp@teddy.UUCP (12/13/85)
In article <1192@panda.UUCP> vxg@panda.UUCP (Vincent Gonzalez) writes: > > Having been convinced >that I should spend some funds on a binocular, opposed to a low price >telescope, my question now whould be: What magnification is best suited >for night viewing? I took a trip to a local camera shop and discovered >a variety of choices 7X50, 8X50, 10X50, 20X50, etc. A chart on their >wall stated that the 7X50 was a good choice for all around use and that >the 10X50 and 20X50 were best suited for "plane sighting", but not recom- >mended for nigh viewing. Hence, I am leaning toward the 7X50. What >will the more powerful glass do for me? What are their drawbacks? > One of the most important consideration I have found for purchasing binoculars is comfort. A 20x80 may be wonderful for looking at the sky, but who is going to want to hold on to such monsters for more than a few minutes. 7x50 and 8x50 seem to be good all-around choices. One other piece of equipment that should be purchased is a comfortable outdoor adjustable lounge chair. This can make the viewing even more comfortable. Take it from someone who is still suffering a sore neck after trying to look straight up at Halley's. Dick Pierce
chris@leadsv.UUCP (Chris Salander) (12/13/85)
1) 70, 80mm lens and larger are some trouble to
use, so you should only get them if you are
really serious.
2) 20x and higher magnifications are also more than
someone just starting out would want.
That leaves the most common: 7x, 10x, 35mm, 50mm.
You would want 50mm if most of your viewing is at
night (to gather more light). If most viewing will
be in the daytime, 35mm is fine.
7x and 10 x I think is just a matter of how much
magnification you would like to pay for. For
astronomy, I would get 10x50, although sometimes
you can get a good deal on 7x50.
Optics still seem to response to price. You can
get a 7x35 for $30 to $90, and the $90 pair IS far better
than the $30 pair. Avoid "Western Field". Tasco
is mediocre. Bushnell is a little better, particularly
because of their "Insta-Focus" lever. I hear that
Nikon is suppose to be fantastic. Macy's has them
on sale.
Finally, the last issue of Astronomy had an article
on buying binoculars. It talked about how to look
for chromatism and aberrations; and how different
binoculars are constructed.
- Chris Salanderfreeman@spar.UUCP (Jay Freeman) (12/14/85)
[] As you probably know, a binocular specification such as 7X50 means "seven power magnification, 50mm-diameter front lenses". For astronomy, light grasp is of the essence, so that the larger the second number is, the better! On the other hand, binoculars that are in some combination too heavy, or magnify too much, cannot be held sufficiently steady without a tripod. Most people have no trouble with a 7X50, but an 11X80 is more difficult to use. I recommend a 7X50 as an excellent instrument for a beginner. There are several good ones available in the $100 range (a bit less on sale, rather more at list price). -- Jay Reynolds Freeman (Schlumberger Palo Alto Research)(canonical disclaimer)
rfc@calmasd.UUCP (Robert Clayton) (01/03/86)
I just got a pair of Swift binoculars that I really like. I looked at a couple others and I can pass on what I learned as I shopped. Every source will tell you that magnification greater than 8X requires a tripod, and they are absolutely right. I had a pair of Bushnells that zoomed from 7X to 15X. They were useless at 15X. The problem is the magnification exagerates any jiggling, and the jiggling was maddening. As a result, I would recommend against buying any such zoom feature. The pair I bought has a heavy rubber case so that you do not need a separate binocular case. Every time I use binoculars, the case is just a fifth wheel so I was anxious to get rid of the case. This is especially important if you also carry a camera on field trips; picture yourself with camera, camera case, binoculars, and binocular case around your neck. I see other vendors are making rubber cased binoculars too so check them out. The two barrels of the binoculars must align with the lines of sight of your two eyes. Eye spacing varies from individual to individual so you will have to try different makes and models until you find a pair that is right for you. This is a very important feature so do not neglect it. It significantly affects your comfort. I chose the Swifts over other more expensive brands primarily for this reason. When it is right, the viewing is very natural; when it's not, one eye blacks out. You will know when you have found the pair right for you. Slotted prism. The Swifts have a slotted prism. The slot sticks up in the optic path through the prism and blocks the transmission of unwanted secondary reflections that cause double images. I expect most good binoculars will have this feature. Low cost ones do not. Ask for it. I don't think you would want to cut corners here since there are honest physics behind this feature. Coated optics. Most lenses use an oil film coating. This can be cleaned and re-applied if necessary, but few people maintain their coatings. A technician in a camera store can do this for you, but still people don't get the work done. Even if you keep an oil coating clean, it will eventually dry out and have to be renewed. The Swifts tout their hard amber coating as being more rugged. I chose ruggedness, but I am not sure what I will do when (not if) I finally do damage the coating. Comments to a previous posting: > > 1) 70, 80mm lens and larger are some trouble to > use, so you should only get them if you are > really serious. > > 2) 20x and higher magnifications are also more than > someone just starting out would want. Amen. And do not forget the tripod. > > For astronomy, I would get 10x50. Me too, but even at 8X I am at the jiggle threshold. If you want to use them at football games and nature hikes too, you will find yourself constantly seeking out props. Have you ever tried propping anything against the mast of a ship rolling at sea? > I hear that > Nikon is suppose to be fantastic. Macy's has them > on sale. Nikon optics are great. My dad was a camera nut who swore by his Nikon. As a result, I am kind of picky too. My camera is a Nikon, though I can't use it to its full capability. I saw a pair of Nikon binoculars for $350 in a camera store and decided that was too much. (Camera stores often carry binoculars and telescopes as a side line. Check discount camera stores. They should beat department stores. Look for ads in the back of photography magazines too.) Two points: 1. You can stare at a cherished photo for years, so the cost is amortized over a very long period, sometimes longer than the life of the camera even. 2. You will someday want to blow up a good photograph so you will appreciate the better optics although film type is also important here. You can enter photographs in contests, sell them for a living and share them among friends. Therefore, I can see going overboard on a camera before I would on a pair of binoculars. Once you get to clear comfortable viewing, you probably do not need more. With all the features discussed above, I put the absolute ceiling price at $150 and won't go higher. Many will be happy with less. Binoculars and cameras are one of the first things stolen, and the nationwide average says your house will be broken into once every six years. Do not buy anything of this nature unless you can insure it or are otherwise prepared to lose it. Thanks also to: > > - Chris Salander Bob Clayton GE Calma R&D San Diego Swift, Bushnell and Nikon are trademarks. All opinions are my own. No product endorsement is given nor should be inferred.