binoculars

[eyeball]

im an outdoor type of guy and I was wondering if anybody knew where I can get some powerful binculars. and I aint talking about the kiddie binoculars that you buy at K-mart but some high powered ones.

what is the longest range binoculars that you have ever seen? anybody know of any?

thanks.

[C.R.Sam]

"Longest range" is an iffy term......Magnification alone does not always determine usable distance. So much depends on optical quality, color correction, mechanical integrity etc. Some of the largest and most powerful are Naval binoculars intended for use from a pintle mount. They are very large, very expensive and the magnification is so high as to make them useless when hand held.

Here is a site that gives some info on better binoculars. They have treated me well for quite a few years.

http://www01.bhphotovideo.com/defaul...ID=E7A15C6D360

You might be suprised at the positive difference between an excellent pair of six power compared to a cheapo ten power.

Try all you can get your hands on. Better gun stores, camera shops etc.

Sam

[C.R.Sam]

Overkill
http://www01.bhphotovideo.com/defaul...ID=E7A15C6D360

On sale, $3,000 off MSRP

Sam

[eyeball]

wow. im surprised at the cost of some of these binoculars. some of them cost as much as cars!

[hksigwalther]

As mentioned above, magnification shouldn't be the only characteristic that you measure a good bino with. Other factors include objective lens diameter, lens quality, lens coatings, etc. Remember, the higher in magnification you go, the more magnified your shakiness will be. I've got a cheapo Tasco 20-60X and at 60X it's very hard to keep the bino stable to get a good look offhand. Need a tripod for that high a mag. Also, cheapos like my Tasco, the higher the magnification, the field of view narrows down severely (that is the black ring around the image when you look through the bino contracts).

[C.R.Sam]

Eyeball............well, you wanted sumpin a grade above the K-mart stuff

Make sure you're sittin down before you look at the really high end stuff.

Actually, there are a lot of quite good glasses out there that don't cost an arm and a leg. Things to look for include....brightness, ability to sharply focus, maintain focus over most of the image area, both sides focus on the same point (collumation) etc etc.

An extreme test is to see if, at night, you can focus on a star and see a single point of light. Very few will do so.

Plenty good enough is to look at a power pole at a mile or so and you should not see two poles. Also check on a cross bar. That way you are checking them for both vertical and horizontal alignment.

Sam

[eyeball]

i bought a pocket-sized pair of binoculars from Big 5 the other day. it was originally $69.99 but was on sale for just $20.00. i just couldn't let the big oppurtunity pass.

it is 12 X 25 mm.

now let me get this straight. the 12 means that I could see something 12 times as far as I would with the naked eye? what does the 25 mm mean?

and how is all of that optical quality-lens coating stuff measured? is it even measured or will I just have to do a "star test" by myself?

and im surprised that I could use binoculars at night. I could actually see stuff clearly at night things I wouldn't normally be able to.

[C.R.Sam]

12 is the magnification factor.....25 is the diameter of the objective (front) lens in milimeters. There is a bit of light lost in passing through each lense element. Certain coatings help to reduce this loss. A lot more involved than that but that is the short n sweet version.

All other factors being equal.....larger objective lense allows more total light to enter the instrument......thus more capability in low light situations. Also, usually, larger objective lens will allow larger field of view. More area at a given distance.

Smaller objective of course makes em handier to carry.

Sam

[Dave R]

There is a tradeoff between the magnification and the size of the objective lens as it relates to brightness. For example, for a 25mm lens (the 2nd number):

-an 8X25 will be brighter than a
-10X 25, which will be brighter than a
-12 X 25

The lower magnification (smaller first number) will also have a wider field of view than the higher magnification (bigger first number).

This all affects how usable the binoculars will be in the real world. For example, I have a 10X 25 "pocket" binocular. Good German manufacturer. I also have a 7X35 binocular from a mid-range American manufacturer. I took 'em both to a football game. I only use the 7X35 after that. The 10X25, even though it had higher magnification, was much less usable. It was dimmer, and it had such a small field of view that I couldn't follow what what was happening. It was like looking through a really narrow tube.

So, for a binoculars you would use for spotting paper targets, which don't move, and are generally seen only in bright light, a high power and small lens might work. But for real-world use, i.e. hunting or even sight seeing, you'll want a bigger, brighter lens.

IMHO, if you want a 7-power bincular you want at least a 35mm lens. If you want a 10-power binocular, you'll want a 50mm lens.

Try a bunch at the store an you'll see what I mean.

[C.R.Sam]

There is going to be a quiz on this thread at the end of the week.
And I'll probably flunk it.

Any piece of glass difracts different colors of light at slightly different angles.

When lookin at a paper target it matters little whether your glass focuses all colors equally (color correction). This situation changes a bit when lookin at real targets of variable color. Then it sometimes becomes impossible to focus sharply on the whole target with a simple glass. This can be compensated for by various coatings and the addition of more elements (lenses) internally. Trouble with precise color correction is there is a loss of transmitted light at each interface......goin into and out of a piece of glass. Therefore the more elements, the less light gets through to your eye.

I have some VERY expensive telephoto camera lenses that are nearly color focus perfect. I have converter/erector to use them as telescopes/spotting scopes. Trouble is even with 120mm objective lense, there are so many elements that they only make good scopes on a very bright day.

Life is a compromise........but I want it MY way.

Can't eat your pie and keep it too.

Sam

[eyeball]

damn, all of you guys are experts.

well basically, i am fortunate to live in a house with a great view. from my backyard I can see Mexico (I live 25 minutes away from the San Diego/Tijuana border). I just wan't a really powerful quality pair of binoculars so powerful that I could actually see people walking the streets of TJ so the range from by backyard to inside the streets of TJ is around 25 miles. and the advantage is that Tijuana is situated on a steep hill so I have a good view as opposed to if it was on flat land.

is that even possible to have a pair that strong? what numbers would you recommend.

[bobs1066]

eyeball, you've also got to consider what sort of atmosphere you will be looking through. If you are 12,000 feet up in the Rockies & looking at something 5 miles away through a good pair of binos, you will see it much better than the same distance & same glasses operating as sea level & going through five miles of smog & heat monkeys...my $0.02 is that to be able to discern the motion of individuals at 15+ miles, you will need a telescope & a good steady tripod...

[C.R.Sam]

Probably be cheaper to move closer. ...Sam

[hksigwalther]

Sportsman's Guide is selling Cstar (never heard of them) binos with a 20-110X mag range, $135. Unfortunately, they are the size of those pocket binos and the objectives are only 27mm. 27mm! For 110X! As mentioned above, generally the bigger the objective, the brighter the image (eveerything else being equal). IMO, 27mm is way too small for 110X.

Another option that you might want to consider is a telescope for astronomy or those big diameter short length telescopes.

[eyeball]

does anybody know how much farther, in general, a telescope sees as compared to binoculars?

A good telescope can see well into outer space. You should be able to see 25 miles with one, I imagine.

wow. im surprised at the cost of some of these binoculars. some of them cost as much as cars!

You should see what some nice guns cost.

[hksigwalther]

Something like this Bushnell 405X will run under $200:



You can compare pricing and power at

http://www.thecameraclub.com/cgi-loc.../web_store.cgi

This is about as far as my reflective/refractive telescope knowledge goes.