Which binoculars should I get?

[mgton]

I've been looking at these Galileo binocs. It says that the binocs are fully multi-coated, but for that price can I really trust that they will be?

http://www.amazon.com/gp/product/tech-data/B0001DJJ4E/ref=dp_nav_0/103-1589931-0439019?%5Fencoding=UTF8&n=502394&s=photo

Also, I was looking at these eagle optics binocs. I wonder if these are truly fully multi-coated? http://http://www.amazon.com/gp/product/B0002CTXYA/sr=1-107/qid=1136268014/ref=sr_1_107/103-1589931-0439019?%5Fencoding=UTF8 (http://www.amazon.com/gp/product/B0002CTXYA/sr=1-107/qid=1136268014/ref=sr_1_107/103-1589931-0439019?%5Fencoding=UTF8)

Konica and Nikon are some more brands that I am looking at, anybody have any knowledge of these brands.

Here are some Konica zoom binocs: http://http://www.amazon.com/gp/product/B00009XV27/sr=1-99/qid=1136268014/ref=sr_1_99/103-1589931-0439019?%5Fencoding=UTF8 (http://www.amazon.com/gp/product/B00009XV27/sr=1-99/qid=1136268014/ref=sr_1_99/103-1589931-0439019?%5Fencoding=UTF8) Are zoom binocs a good idea or what?

thanks for all the info on this forum, I do a ton of searching on these forums for astronomy info!

[redshifter]

I'm getting http error and can't view the products you're interested in. Generally, zoom optics aren't nessarily a good idea, you get fair performance at the various magnifications, but not great. Are you just starting out in binocular observing? Will these binocs be for terrestrial observing as well as astronomical? What is your budget? If it were me, I'd take a look at these: http://www.telescope.com/shopping/product/detailmain.jsp?itemID=318&itemType=PRODUCT&iMainCat=5&iSubCat=37&iProductID=318&relateInfo=3&compareList=314&add=yes#tabLink they have a nice wide field as well as a good eye relief.

[mgton]

Oops, I fixed the link, it should work now.

I'm trying to find a nice pair for about $100, 7 or 10x50's, BAK 4 multi or fully multi-coated.(is there a big difference between multi and fully-multi) The binoculars are strictly for astronomy.

I have some 8x21's that I don't really know the quality of, last night I was looking at Orion and spotted that cool little thing hanging from his belt. I looked it up on the net and its pretty impressive, it just looks like a gray fuzzy thing in my binoculars though. One question that I do have is if I get a quality pair of 7x50's I wont be able to see anything more than what I can see with my 8x21's right? I mean, it will no doubt be clearer and brighter because of the increased aperture but since the magnification actually goes down a bit, doesn't that mean that I will see the same stuff but just clearer and brighter?

[redshifter]

BAK-4 refers to the optical glass used in the prisms, BAK-4 is pretty good (boro silicate glass I believe, though I could be wrong). Fully multi coated means every air to glass surface is multicoated, which is a good thing. IIRC, every time light passes through a glass surface, 5% of the light is lost. Binocs have several glass surfaces (an assortment of lenses and prisms), so light loss can be pretty high. Single coatings reduce the 5% loss down to about 1%, and multi coatings reduce that even further. So, I'd look for the following:

BAK-4 prisms
Fully multi coated
Wide field of view (at least 5 degress for 10X50's)
Good eye relief (at least 12-15mm) Eye relief is the distance your eyeball has to be from the eyepeice to see the full feild of view. Longer is better, anything under about 10mm and it'll seem like you're cramming your eyeballs against the binocs.

At your budget of 100, it will be difficult to meet the above criteria. The Orion nebula (M42) you refer to will look like a 'gray fuzzy thing' in most binocs (you need more magnification than most binocs provide to see M42 in all it's glory, and more aperature doesn't hurt either), but ones with better optics will be much clearer. A good binocular target is the moon, and that also will be much clearer with good binocs, as well as scanning the summer milky way (my favorite thing to do with binocs). The binocs I linked to will perform head and shoulders above you 8X21's. I'm not familiar with the binocs you linked to, and there's no info about eye relief. You might check these: http://www.telescope.com/shopping/product/detailmain.jsp?itemID=307&itemType=PRODUCT&iMainCat=5&iSubCat=37&iProductID=307&relateInfo=1&add=yes#tabLink the 7X50's have a nice 20mm eye relief, the 10X50's have only a 12mm eye relief, you might try before you buy. Orion is really good about returns. Both of those have a nice wide field, use BAK-4 prisms, and are fully coated (multicoated on the objective lens).

[mgton]

hey thanks for the info. I've been looking at those orions, I have a orion catalogue that I like to look through. The only problem with the scenix binocs is that they are on backorder until march. Does anyone have any experience with Celestron binoculars? I'm thinking about getting these http://www.telescopes.com/products/Celestron_Outland_LX_10x50_-_Porro_38176.html

[aurora]

Those should be OK. I have used Celestron binocs, but not those specific ones.

[Wolverine]

hey thanks for the info. I've been looking at those orions, I have a orion catalogue that I like to look through.
FWIW: I have a pair of Orion 15x80 Megaview binos, tripod-mounted. They're marvelous.

Does anyone have any experience with Celestron binoculars? I'm thinking about getting these http://www.telescopes.com/products/Celestron_Outland_LX_10x50_-_Porro_38176.html
My only experiences have been with Celestron's SkyMaster series and the Ultimas (the former are quite comparable to Orion's offerings). The Ultimas are much more than you're wanting to spend, but wow are they impressive. Excellent optics, magnesium barrels, incredibly light weight. They're been upgraded (http://www.celestron.com/prod_pgs/bino/ultima.htm) for 2006 as well.

[redshifter]

Those Celestrons look pretty good to me, they probably would do as well as the Orions at that price point. They have 18mm eye relief, which is pretty good.

[mgton]

It's strange that Celestron advertises the Skymaster series as binoculars for astronomy and yet only one has an exit pupil of even 5, the Outland LX series is the same way. I wish they had some 7x50's or better yet 10x70's, but I guess I'm going to go with the Celestron Oultand LX10x50's because they are fully-multi coated unlike the skymasters that are multi-coated. Thanks for all the help and will make some posts after I get them and tell ya what I think about them.

If anybody is interested, I came across these at amazon.com, http://www.amazon.com/gp/product/B00008Y0VN/sr=1-32/qid=1136497598/ref=sr_1_32/002-4009614-9968804?%5Fencoding=UTF8 They are Celestron Skymaster 15x70's for $68. I would get them myself but with an exit pupil of only 4.6 I figured they would be pretty blurry.

[Dave Mitsky]

Any binocular that offers higher magnification views for a given aperture will have a smaller exit pupil. If you aren't observing from a very dark site or are over 40 years of age, it's unlikely that the pupils of your eyes are going to dilate to much more than 5mm anyway.

Would you use a telescope at only an exit pupil of 7mm?

Dave Mitsky

[Kaptain K]

I would get them myself but with an exit pupil of only 4.6 I figured they would be pretty blurry.
Huh! What does exit pupil have to do with "blurriness"? Which do think has a "blurrier" image - 30x150 Fujinon (5mm exit pupil, $11,000) or 7x50 dept store specials (7mm exit pupil, <$50)?

[redshifter]

Anyone over the age of about 35-40 doesn't have an exit pupil of 7mm, as Dave already stated. Smaller exit pupils won't result in blurriness. My 25X100 Celestrons have an exit pupil of 4mm, they aren't blurry, neither are my 15X70 Orions, nor is my 9.5mm eyepeice in my XT10 telescope (a 2mm exit pupil).

[mgton]

I was just repeating what I have read, I'm new at this stuff. Here is what I read about exit pupil.

"You can see the exit pupil as a circular beam of light in the eyepiece when you hold the binocular at arm's length. The main importance of the exit pupil is how it relates to the pupil size of your eye. The eye pupil is controlled by the iris, which acts like a variable aperture for the retina and will allow the pupil to change in size from about 2mm up to 8mm, usually depending on the brightness of the available light. When the exit pupil of the binocular is larger than the eye pupil, some of the light coming from the binocular will fall on the iris and is undetected by the observer. When the exit pupil is smaller than the eye pupil, then the amount of light falling on the retina will be less than that collected with your normal vision at that particular time, and so the object observed will appear dim. Resolution and contrast are affected adversely, resulting in loss of clarity of the observed image."

My thinking was that since I'm only getting binoculars and since they are limited in terms of magnification (hand-held binocs), I should be damn sure that the image is crisp and clear so it will be enjoyable. Hey, I don't want to be right, I want to be correct. Help my understand:) Again, I'm new at this, this will be my first real pair of binoculars and I'm excited about checkin out the night sky. By the way, my eyes are only 23 and I do have some dark sites where I could go.

[redshifter]

If this is your first pair of binocs, get a good pair of 10X50's and don't worry about not having a 7mm exit pupil. Those are about the limit of hand holdability. Eye relief and hand holdability will be more important from a usability standpoint than a 7mm exit pupil. That description of exit pupil you pasted is somewhat oversimplified. For example M31 through a 10X50 binoc will look amazing, even with 'only' a 5mm exit pupil. It may look slightly dimmer than say through a 7X50 binoc, but since M31 is a very bright object, in practice it won't matter. A good 10X50 will be plenty crisp and clear. At your budget, optical quality will have a much much greater effect on clarity than any difference in exit pupil.

[Dave Mitsky]

I was just repeating what I have read, I'm new at this stuff. Here is what I read about exit pupil.

"You can see the exit pupil as a circular beam of light in the eyepiece when you hold the binocular at arm's length. The main importance of the exit pupil is how it relates to the pupil size of your eye. The eye pupil is controlled by the iris, which acts like a variable aperture for the retina and will allow the pupil to change in size from about 2mm up to 8mm, usually depending on the brightness of the available light. When the exit pupil of the binocular is larger than the eye pupil, some of the light coming from the binocular will fall on the iris and is undetected by the observer. When the exit pupil is smaller than the eye pupil, then the amount of light falling on the retina will be less than that collected with your normal vision at that particular time, and so the object observed will appear dim. Resolution and contrast are affected adversely, resulting in loss of clarity of the observed image."

My thinking was that since I'm only getting binoculars and since they are limited in terms of magnification (hand-held binocs), I should be damn sure that the image is crisp and clear so it will be enjoyable. Hey, I don't want to be right, I want to be correct. Help my understand:) Again, I'm new at this, this will be my first real pair of binoculars and I'm excited about checkin out the night sky. By the way, my eyes are only 23 and I do have some dark sites where I could go.

What was the source of that information?

Visual resolution is a function of aperture, not exit pupil. Within limits, a higher magnification (and therefore smaller exit pupil) view yields greater "contrast" between celestial objects and the background sky.

Multiplying the aperture of a binocular by its magnification gives an "astronomical usablity" index. So 500 (10x50) is better than 350 (7x50).

Dave Mitsky

[mgton]

So basically exit pupil is irrelevant as far as the image is concerned, as long as its not 20 or something ridiculous like that?

[aurora]

So basically exit pupil is irrelevant as far as the image is concerned, as long as its not 20 or something ridiculous like that?

If it is higher than 7 or so (depending on your eyes and the darkness of your site) then some of the light will be wasted. When it gets really low, like around 2, then the image gets dim and the field of view is small (in a telescope, I mean, because to get the really small exit pupils you use high power eyepieces).

I find an exit pupil of 5 is about right for me with binoculars.

YMMV.

[diskmaster]

Mgton:
I think you might be confusing the terms dim and blurry: blurry has more to do with out of focus and dim the amount of light gathered and delivered to the eye
for the optic nerve to tranfer to the brain to process.
Doug