Selecting binoculars

[HenryC]

Deleted 12/10/09 - HC

[Salty19]

HenryC, thanks for the articles you've been writing.  They are appreciated!

I use a 5 x35 Leopold, mainly for bird watching or spotting other friend sailors on the water (and the local constable!). My wife uses them to look at Blue Herrons and the deer along the shoreline.  They allow you to focus each lens separately, but the optics in low light are not that great. At dusk you simnply cannot make out objects whose colors blend in with the environment (such as deer against a forest floor).  At dusk you can see the deer, but can't tell if it's a rock, a deer, or just a brown spot.  During the day this is not a problem.  Definitely get one with decent light gathering capabilities.

Was considering buying a decent quality monocular instead for convenience reasons (easy to stick in your pocket and easy to deploy quickly).  Plus the eye relief is not sufficient on the leopolds wearing glasses and I don't like taking my glasses off while sailing (Mr. Jones will surely take them away from me!).

The 7 X50's are probably too much for small lakes -judgement call only here--
but just right for open bodies of water.  If you're a little shakey in the hands, try to stay with lower magnification.

[Steve Ullrich]

I had an opportunity to look through some self focusing/permanent focus binoculars this fall.  I was amazed at how clearly I could see with them.  I have monocular vision... That means my eyes are different.  I am far sighted in my right eye and near sighted in my left.  That has created all sorts of problems for me but that wasn't an issue with these binoculars.  I could see clearly with them, with both eyes.  It was like magic.  I'll have a pair before hitting the water again next summer.  Some reading material:

http://www.bestbinocularsreviews.com/self_focusing_binoculars.php
http://www.binoculars.com/search/index.cfm?Ntt=auto%20focus&Ntk=all

[Craig Weis]

I always heard that the ratio of the small eye ball lens to the big, other end lens, ought to be about 4 or 5 to 1.

I have no idea if that is correct.
The wife's birding bioculars are Leitz Trinovid 10 x 40 BA, or 110 m @1000 m. I guess this is very good, designed for close focus.
The seeing clearly trick is to focus on one eye then re focus using both eyes on ONLY the eye piece not used the first time around.
skip.

[HenryC]

The ratio of the eyepiece  to objective lens sizes depends on the design of the optical system, but by itself tells you little.  Like all highly engineered devices, even high quality binoculars are a compromise of competing parameters, such as magnification, eye relief, light gathering ability, field of view, ease of focusing, close-focus distance, mechanical robustness, etc.  Some optical characteristics, particularly in-close focus, field of view and eye relief, are expensive to design and fabricate and not necessary for everyone or every application.  If your binocular has a standard field of view it doesn't mean it's of low quality,  and the converse is also true: a super-wide field of view MAY have been paid for by skimping on something else. I personally don't require one, so I won't pay extra for it, but in some applications (like watching fast-moving sports) it is very helpful.

For boating on small craft, I use a 7x50 monocular because it is easier to use and requires less fumbling around with, and is lighter to carry.  On a larger, more stable boat, I would go with the 7x50 binoculars, because storage is less of a problem and you're generally not in a hurry.  For general use, I prefer 10x50 binos, because I have extremely steady hands but my aged pupils don't open up to a full 7mm any more.  I don't do much birding these days, but for that I prefer a very portable and higher power day glass, a 10x35 monocular or thereabouts, with a very in-close focus capability.

As for the single focus (no need to focus at all) instruments now on the market, I must be fair and say I have never tried one myself.  But I would guess they just sound too good to be true.  I simply can't see how they are supposed to work, they appear to violate the laws of optics.  And if they do work, my guess is they have to compromise something for that convenience.  I know my eyes are so different in focus from one another that I can't see how a compromise, one-size-fits-all setting could possibly work for everybody, all the time.  With the focussing arrangement I recommend, even someone with Steve's "monocular vision" should be able to use a two-focus adjustment  to utilize both eyes simultaneously.  Believe me, that makes all the difference in the world as far as comfort and clarity of vision are concerned.  Still, you need to be able to field test the glasses to make sure the two focussers have the range to accommodate both eyes simultaneously. If your eyes are seriously different, this may not be possible.  In that case, I recommend a monocular.  Having two glasses when you've got one eye shut makes no sense at all.

I currently own three night glasses:  a 7x50 monocular, a 10x50 bino, and 11x80 "Big Eyes" for deep sky astronomy. All three are center focus with a right eyepiece adjustment. The latter do require a tripod or something to lean on while using them because of their high power and weight.  I use the 10x50 most of the time, even to back me up when I'm using my telescope. For me, 10x50 is the best overall compromise.

[Craig Weis]

Like I said, I have no knowledge of what is good with binoculars, only what I heard.
But now I do. Thanx Henry.
skip.

[Steve Ullrich]

Excellent information Henry.  I'm still suggesting that anyone looking for a new pair of binoculars take a peek through permanent focus models before making a decision.
Perhaps you should take a look through a pair of permanent focus binoculars, you can find them at Fleet Farm and other places.  You may well be as amazed as I was.  They aren't too good to be true. The trade off is that they focus from approximately 40 yards to infinity.  I won't pretend to understand the optical specifics but I don't need binoculars for objects within 40 yards so the permanent focus glasses will work perfectly for me on local lakes and rivers.  No fumbling, no individual focus to toy with, you just see clearly.  As I said, I have monocular vision.  I'm nearsighted in one eye and far sighted in the other.  Looking through these glasses was the first time in years that I could see sharp clear images at a distance.  It is magic.  I have a pair of 7x50 permanent focus binoculars on my Christmas list.  If the admiral doesn't come through I'll get them from Santa for sure. 

The ratio of the eyepiece  to objective lens sizes depends on the design of the optical system, but by itself tells you little.  Like all highly engineered devices, even high quality binoculars are a compromise of competing parameters, such as magnification, eye relief, light gathering ability, field of view, ease of focusing, close-focus distance, mechanical robustness, etc.  Some optical characteristics, particularly in-close focus, field of view and eye relief, are expensive to design and fabricate and not necessary for everyone or every application.  If your binocular has a standard field of view it doesn't mean it's of low quality,  and the converse is also true: a super-wide field of view MAY have been paid for by skimping on something else. I personally don't require one, so I won't pay extra for it, but in some applications (like watching fast-moving sports) it is very helpful.

For boating on small craft, I use a 7x50 monocular because it is easier to use and requires less fumbling around with, and is lighter to carry.  On a larger, more stable boat, I would go with the 7x50 binoculars, because storage is less of a problem and you're generally not in a hurry.  For general use, I prefer 10x50 binos, because I have extremely steady hands but my aged pupils don't open up to a full 7mm any more.  I don't do much birding these days, but for that I prefer a very portable and higher power day glass, a 10x35 monocular or thereabouts, with a very in-close focus capability.

As for the single focus (no need to focus at all) instruments now on the market, I must be fair and say I have never tried one myself.  But I would guess they just sound too good to be true.  I simply can't see how they are supposed to work, they appear to violate the laws of optics.  And if they do work, my guess is they have to compromise something for that convenience.  I know my eyes are so different in focus from one another that I can't see how a compromise, one-size-fits-all setting could possibly work for everybody, all the time.  With the focussing arrangement I recommend, even someone with Steve's "monocular vision" should be able to use a two-focus adjustment to utilize both eyes simultaneously.  Believe me, that makes all the difference in the world as far as comfort and clarity of vision are concerned.  Still, you need to be able to field test the glasses to make sure the two focuses have the range to accommodate both eyes simultaneously. If your eyes are seriously different, this may not be possible.  In that case, I recommend a monocular.  Having two glasses when you've got one eye shut makes no sense at all.

I currently own three night glasses:  a 7x50 monocular, a 10x50 bino, and 11x80 "Big Eyes" for deep sky astronomy. All three are center focus with a right eyepiece adjustment. The latter do require a tripod or something to lean on while using them because of their high power and weight.  I use the 10x50 most of the time, even to back me up when I'm using my telescope. For me, 10x50 is the best overall compromise.

[HenryC]

I haven't looked through them, but I did read the website describing them, and I think I understand them a little better.  They are simply focused at infinity, so if your eyes are normal (focused at infinity) they should work ok.  The reason I feel skeptical about them is that my eye focus changes over time (an astronomy observing session can last for hours, during which you are actually looking through the glasses about half the time), so with sharp, point images, like stars, even a slight change of focus is easily noticeable. I am constantly adjusting the focus as I look through the glasses, then look away at my charts, etc. 

There is also the issue of "near" and "far" or "depth of field" focus (related to what photographers call "Hyperfocal Distance").   Your eye is capable of refocusing to a sharp image even if your optics are slightly out of focus.  This will be perfectly acceptable, but it can lead to fatigue over long sessions.  You will note that as you focus "in", the image will first appear sharp, but it will remain so even if you focus even further in.  Eventually, it goes out of focus again.  Somewhere in that range is where the eye and the glass are both focused at infinity, and therefore you are most relaxed and comfortable. 

If you are someone who will be spending very long periods of time looking through the glass, as will a ship's lookout, or an astronomer, all this is worth following up on.  You want to be able to completely control what you see.  OTOH, if you just want to double check the number on a buoy, you probably don't want to spend too much time fiddling with your gear.  As always, get what works for you, and keep in mind that the condition of your eyes may be such that it really doesn't matter that much what you're looking through.  The limiting factor may not be your equipment, but you!  I am very fortunate in that I still have excellent distance vision for a person my age, even though my ability to read is pretty much non-existent without my cheaters.

[nies]

Steve, I have the same eye problem, will look into a pair........Phil

[Bob23]

Hmmm...wonder why Henry deleted his post?
Bob23, the inquisitive

[curtisv]

http://www.bestbinocularsreviews.com/self_focusing_binoculars.php
http://www.binoculars.com/search/index.cfm?Ntt=auto%20focus&Ntk=all

Steve,

Fixed focus make sense on a boat if you are trying to read the number off a buoy in the distance rather than carefully examine the bird on a nearby buoy.  I think all of the marine binoculars that have per eyepeice adjustments are either fixed focus or very optimized for distance.  Its the center focus ones you want to avoid.

The first link was a good review and if you click on "Marine Binoculars" there is good advice there too (http://www.bestbinocularsreviews.com/marine-binoculars.php).  The best peice of advice there is "Obviously a waterproof binocular is the single most important feature of a marine binocular."  That whole paragraph is worth considering carefully, including the part about nitrogen purged.

The consensus on marine binoculars is 7x is the right magnification.  Any higher and you can't keep them steady enough on a moving boat.  I think you should go with 7x50 rather than 7x35 or 7x30, if you plan to be out after dusk as the second number is the big end size in mm and the bigger, the more light it lets in.  If you day sail only then the higher cost of the 7x50.

I prefer a compass for two reasons, though both might not apply to most sailors.  When you see a big commercial vessel on the horizon it is nice to be able to easily take bearings and know that you won't hit it.  Also if you know how far off the wind you are sailing (varies a little with conditions) you can get a bearing on a distant destination and not tack until you can make it in one tack.  The wind is usually stronger farther off shore so this serves two purposes.  A separate hockey puck hand bearing compass would also work, but I like the binoculars.

When Tasco was first trying to break into the binocular business they underpriced some very good binoculars.  Since then binoculars have come way down in prices.  Thes the ones I have are at this incredibly long URL http://www.google.com/products/catalog?hl=en&source=hp&q=tasco+binoculars&oq=&um=1&ie=UTF-8&cid=14745265749120782873&ei=fj-LS_24A4iqtgPn4KCGAw&sa=X&oi=product_catalog_result&ct=result&resnum=4&ved=0CDkQ8wIwAw#ps-sellers (at about half what I paid for them about 8 years ago).  These have per eyepeice adjustment and don't need refocus for distance viewing.  If you play with them in the yard or elsewhere and focus close they seem to me to be fine down to 20-30 feet but with a little turn of the eyepeice.  The antiglare coating is also nice - something you'd appreciate if you sight a buoy that is just in front of the sun low on the horizon.

Curtis

[Bob23]

   I purchased a pair of 7x50's at West Marine on sale a while back. About 100 clams on sale, if my memory serves me well. Waterproof and it's claimed that they float although I've never had the nerve to throw them overboard to try.
   While on lunch a few years ago, my over-inquisitive son decided to take them apart and, in doing so, broke 'em. I took them back, explained the situation (truthfully) and noted that I did not have the reciept but I knew they were old enough to be outside of the warranty. They replaced them on the spot! It does pay, sometimes, to deal with the locals.
Bob23, the far-sighted

[HenryC]

Hmmm...wonder why Henry deleted his post?
Bob23, the inquisitive

Copyright reasons.  I'm trying to get it published and have submitted it to a magazine.
HC

[Steve Ullrich]

Curtis - Thank you very much for the information and related links.  As I'm hip deep in snow I haven't bothered to run out and buy binoculars just yet.  A lighted compass and rangefinder would be wonderful.  I'll consider the Tasco OS36 very seriously.

Steve

http://www.bestbinocularsreviews.com/self_focusing_binoculars.php
http://www.binoculars.com/search/index.cfm?Ntt=auto%20focus&Ntk=all

Steve,

Fixed focus make sense on a boat if you are trying to read the number off a buoy in the distance rather than carefully examine the bird on a nearby buoy.  I think all of the marine binoculars that have per eyepeice adjustments are either fixed focus or very optimized for distance.  Its the center focus ones you want to avoid.

The first link was a good review and if you click on "Marine Binoculars" there is good advice there too (http://www.bestbinocularsreviews.com/marine-binoculars.php).  The best peice of advice there is "Obviously a waterproof binocular is the single most important feature of a marine binocular."  That whole paragraph is worth considering carefully, including the part about nitrogen purged.

The consensus on marine binoculars is 7x is the right magnification.  Any higher and you can't keep them steady enough on a moving boat.  I think you should go with 7x50 rather than 7x35 or 7x30, if you plan to be out after dusk as the second number is the big end size in mm and the bigger, the more light it lets in.  If you day sail only then the higher cost of the 7x50.

I prefer a compass for two reasons, though both might not apply to most sailors.  When you see a big commercial vessel on the horizon it is nice to be able to easily take bearings and know that you won't hit it.  Also if you know how far off the wind you are sailing (varies a little with conditions) you can get a bearing on a distant destination and not tack until you can make it in one tack.  The wind is usually stronger farther off shore so this serves two purposes.  A separate hockey puck hand bearing compass would also work, but I like the binoculars.

When Tasco was first trying to break into the binocular business they underpriced some very good binoculars.  Since then binoculars have come way down in prices.  Thes the ones I have are at this incredibly long URL http://www.google.com/products/catalog?hl=en&source=hp&q=tasco+binoculars&oq=&um=1&ie=UTF-8&cid=14745265749120782873&ei=fj-LS_24A4iqtgPn4KCGAw&sa=X&oi=product_catalog_result&ct=result&resnum=4&ved=0CDkQ8wIwAw#ps-sellers (at about half what I paid for them about 8 years ago).  These have per eyepeice adjustment and don't need refocus for distance viewing.  If you play with them in the yard or elsewhere and focus close they seem to me to be fine down to 20-30 feet but with a little turn of the eyepeice.  The antiglare coating is also nice - something you'd appreciate if you sight a buoy that is just in front of the sun low on the horizon.

Curtis

[tmolik]

I liked your cover..
What kind of compass have you mounted on your starborad bulkhead
thanks
tom