OpticsBlog – Thoughts and reviews of binoculars, telescopes, scopes, sights, and much more - birdwatching, astronomy, target shooting - pretty much anything related to optics, nature, and life!

Not too many years ago, everyone assumed that the maximum exit pupil (second binocular number divided by the first number) commonly offered in a binocular - 7mm -was the best choice for an astronomy binocular, because on paper, a 7mm exit pupil will give you the maximum image brightness and therefore allow you to see fainter objects. That's why a 7x50 was traditionally the classic astronomy binocular for many, many years and a good one, such as the Nikon 7x50 Sports and Marine binocular still makes an excellent choice.

Then came the giants with larger 70mm and 80mm objectives. This made it possible to offer even more magnification and still maintain a large 7mm exit pupil. 10x70s and 11x80s were the hot products. I have owned many of these and currently use a Nikon 10x70 Astroluxe binocular, not so much for the larger exit pupil as the excellent optics and construction. It's a true astronomy classic.

The market then shifted to giants with more magnification and therefore smaller exit pupils. The 20x80 with its 4mm exit pupil became the best selling giant (and still is, today). There are so many good 20x80s, I can't list them all, but I have always liked the Oberwerks, such as the Oberwerk 20x90mm Binocular with hard case. It's one of the best giant binoculars I have used for the price.

The 10x50 with its smaller 5mm exit pupil has largely replaced the 7x50 as the handheld astronomy binocular of choice and you don't have to spend a fortune to get a good one. Under $200, I like the Nikon 10x50 Action Extreme Waterproof Binoculars 7245 and the Pentax 10x50 PCF WP II Binoculars - 65808.

The bottom line is that we astronomers have learned over the years that an exit pupil (second binocular number divided by the first number) of 4mm or 5mm is plenty for nearly any type of binocular astronomy and that most users are seldom in the position to take advantage of larger exit pupil models. This is especially true if you observe under light polluted skies and have to deal with nearby lights (since the pupils of your eyes never completely open to their widest). It is also a fact of life for most of us past the age of forty or so, since our eyes can no longer open wide enough to use larger exit pupils.

Joanie

I received this comment from one of our readers,recently.

"I see you have LOMO microscopes and I would like to know what you think of them. You sound very experienced and I cant find reviews on them anywhere! Thanks! (And BTW, you sound like a great Lady!"

First of all, thank-you for the nice comments and for reading my blogs.

I own several LOMO microscopes such as the LOMO SF-100 stereo microscope and the LOMO Multiscope BMH4-BF microscope. You can also purchase these and other LOMO microscopes from our OpticsPlanet.net website at LOMO microscopes.

I own them specifically because I want 1)top notch, all metal, heavy-duty construction and 2)great optics for the dollar. Sure, I would love to own a Nikon or Olympus many thousands of dollars, but for a hobbyist like me, that's a little out of my price range. However,I do want a quality microscope and it's nice to get one made in Russia the old fashioned way. A lot of our professional and industrial customers feel the same way and they buy a lot of LOMOs from us. Really can't make a mistake buying a LOMO.

The idea that you can make deep-sky (faint objects) more visible by increasing magnification (and decreasing exit pupil) has been circulating for sometime. The idea is that increasing magnification will darken the sky background, thereby making faint objects stand out more. How much truth is there to this notion?

In my experience, it does work - sometimes. In other words, it is like many other observing techniques. It works, but not all of the time. There are simply too many variables in observing for a one-size fits all approach. I've had my best luck with this when observing with large telescopes. Large apertures give you more light to work with and using a telescope gives you access to many different magnification and eyepiece options. Typically, I've found there will be one combination of magnification and telescope aperture that gives the "best" contrast between the sky background and the object and that, true to form, this is sometimes at surprisingly high magnifications. Of course, this is sometimes at lower magnifications, too. It depends on so many things - the type of object, it's magnitude, your telescope, your eyepieces, your skill as an observer and, perhaps most importantly, observing conditions. We all know those change night by night and even hour by hour. Then, too, what constitutes "best" in terms of contrast is largely subjective. It's as much your call as much as it is the next observer's.

Next, I will look at this notion of increasing magnification to darken sky background and apply it to binoculars.

Joanie

I will be celebrating International Migratory Bird Day tomorrow by working.

Not to worry, this is the type of work I love. I will be representing OpticsPlanet.net at a local park and introducing the general public to two of the things I love the most - birds and optics. And they call this work!
In the past, I have done seminars and classes on both birding and optics and with my tendency to talk for hours on both topics, I will most likely have to have someone pull the plug on me. Never fails.

If you are in the Arlington Heights/Wheeling area of Illinois, stop by beautiful Lake Arlington and see me. (You can see more at the Arlington Heights Park District website.) I'll be there from 10:00 AM until … I stop talking?

I get country of origin questions on optics fairly often and a good many people are disappointed when I tell them that the model in question is made in China. Some of these folks are hoping for "made in Japan" and a few are still seeking the extinct "made in USA" binocular or spotting scope. I understand their concerns, though I have often reminded them that where a product is made is not always a measure of its quality.

If you've been in this industry as long as I have, you remember the days when "made in Japan" was associated with less expensive optics. The majority of these products, however, offered the consumer an affordable and practical alternative to high end European glass and, as such, got binoculars and spotting scopes into the hands of customers who might not otherwise ever own one. I owned many a mid-priced Japanese binocular and spotting scope, myself.

Were those mid-priced made in Japan products from days gone by any better than today's mid-priced made in China products? I don't think so. In fact, with advances in technology, the current Chinese versions may actually offer even more optics for the consumer's dollar. I remember a time when features we now take for granted on most binoculars - full multi-coating, phase correction, waterproofing and more - were only to be found on the most expensive models European models. These days, you can get them on many models under $200.

Part of the stigma of "made in China" is the result of the same market balance that once plagued the "made in Japan" label. These days, what comes out of China is a very mixed bag of optics, just as in the old days of Japanese production - you can buy anything from a disposable toy to a very serious optical instrument. In this sense, it is just as unfair to label all Chinese products as junk as it was back then to label all Japanese models as junk. Today, "made in Japan" is typically associated with quality, solely because the bulk of production has moved to China to hold the line on labor costs. Only more expensive optics are still being made in Japan.

If you still doubt that a Chinese binocular cannot give you good performance, I invite you to look at several I have tested. Under $400, I loved the Pentax 8x33 DCF XP. It tested out better than some better known binos at twice the price. Scary. Can't afford $400? Under $300, try the little known Carson XM HD. The HD stands for high definition and they aren't kidding. You will never buy a better binocular at this price. Can't afford $300? Try the Vortex Diamondback or the Bushnell Excursion. Both offer full multi-coating and phase correction - a miracle at this price.

As far as I am concerned, anyone who wants a solid binocular with enough optical quality for nearly any application can afford one, thanks in large part to "made in China".

Had the Nikon 10x70 Astroluxe binocular out last night under my light polluted and hazy Chicago skies and have to report that even though I didn't see much, I did enjoy using this great binocular. As I stated in my previous post, I buy high end optics to see things as good as they can be seen. After last night, I am now adding a footnote that I also buy high end optics to see things under poor conditions as good as they can be seen. No matter what the conditions, though, observing is always more fun when you use good equipment.

In truth, I knew up front that I would never realize the full potential of this great binocular until I make the journey to a truly dark sky site, but I bought it with that very thing in mind. "Porro parum", carry little is one of the things I live by. Of course, it's all relative. The Nikon 10x70 Astroluxe is a giant binocular, after all, but compared to traveling with a telescope, even this giant binocular is small.

By now you might be thinking that I prefer a binocular for astronomy and, in fact, you would be right. The binocular better suits my on the move lifestyle and simple approach to all things. I'm not sure if my favorite objects are open star clusters as a result of using a binocular for so long or if I use a binocular because my favorite objects are open star clusters, but it's a match made in optical heaven as far as I'm concerned. See you out under the Beehive.

Inevitably, people tend to equate expertise in birding, astronomy and many other optical pursuits with numbers and quantity - how many birds, how long a list, how many deep-sky objects, what detail did you see, what resolution did you obtain and on and on. True, this is a necessary component to gaining expertise and is a valuable tool when communicating with others, but dig a little deeper and you may be surprised to discover that many of us "experts" no longer play the numbers game when we are observing for ourselves.

You see, if it was solely a matter of completing lists or reaching an arbitrary number, many of us experts would have put down the binocular years ago or retired the telescope permanently to the garage. Every list comes to an end and you can only get so clever about re-inventing a new one. For instance, I once kept a weekly bird list, a monthly bird list, a seasonal bird list and, of course, a yearly and lifelong bird list. I then started to create bird lists by state as I moved around the country. As for astronomy, I kept a binocular list, a small refractor list, a list for my Dobsonian, then started lists for different locations.

Okay, true confessions time. I haven't kept a list for a long time. This sometimes surprises and even shocks some people, especially those who look to me for advice on optics. Don't get me wrong; I still believe in lists and I do encourage others to use them for learning and motivational reasons - anything that gets you out and observing is a good thing. Lists, however, are but a step in the journey and a tool. The best advice I can give to anyone is to look beyond the list. It's the experience that counts, not the list.

The truth is, I, like many others I know, continue to observe because I am hooked on the beauty of what I see. The things I remember and cherish the most are qualitative, not quantitative. It was that first look at Saturn; it was that glorious clear night with the Zeiss binoculars that nearly brought me to tears. The vision of M7 on that night is forever locked in mind, though I have seen M7 many, many times since. In like manner, I will never forget that foggy spring morning when a Prairie Falcon swooped out of nowhere and made every Prairie Chicken I had been watching disappear as if by magic.

I spend the big bucks on optics, then, not to add things to my list, but to enhance the experience. I don't just want to see;I want to see something the best it can be seen. Will an inexpensive Oberwerk 11x70 binocular see nearly the same number of things as my precious Nikon 10x70 Astroluxe binocular? Actually,it won't be that far behind, especially under my light-polluted skies. Will the Oberwerk 11x70 show things as beautifully crisp, clear and bright as the Nikon 10x70 Astroluxe? No, definitely not. That's why I skipped a lot of lunches to pay for the Nikon.

My treasure trove of memories is full to overflowing, but I would not trade a single one for any list I have ever kept. I continue to observe because I have fallen so deeply in love with what I see and if you could peer into my soul, you will find endless visions of prairies, forests, mountains and marshes. If I am tempted to measure anything, it is to count the number of people I have helped in their journey to love these things as much as I do.

One of my favorite times of the year to do astronomy with a binocular is in the summer. This season offers not only variety, but also abundance for the binocular observer. It is hands down the best time of year to collect globular clusters with all these beauties a person could want in and around Ophiuchus and Sagittarius, alone. Of course, no discussion of globulars is complete without mention the most famous one of all, M13, in Hercules and, hey, don't forget M5 and M4. How can you even pick a favorite, here?

My first love, though, in the summer sky in a binocular is the grand open cluster M7 in Scorpius. The first time I saw it glimmering, low on the horizon in Scorpius, it took my breath away. Yes, the Pleiades in fall and winter are stunning in their brilliance, but I've always thought M7 has a majesty and sweep that fills the field of binocular like no other open cluster. To me, it has always seemed somewhat mysterious as well, located as it is not far from the great Sagittarius star fields. The problem is, that M7 is too low on the horizon for many northern observers to get the full effect.

Would I travel south just to see it? Offer me a dark sky, a gentle night breeze and a tripod mounted Nikon Astroluxe 10x70 binocular and see what happens.

Have bike (actually, bikes plural), will ride. That describes a big part of my life and most of what I did this weekend. It's part of Joanie's three Bs - bikes, binoculars and birds. It's a unique combination of interests in that a person can practice all three at the same time.

This weekend, I put a lot of miles on both dirt trails and paved trails, all the while with a Nikon Premier LX 10x25 binocular around my neck. Going compact keeps the weight down and weight is a nemesis for long distance bike work. Though a compact, the optics on the Premier LX are top drawer all the way and, to be honest, are good enough not to justify the weight of a larger binocular.

For birds … well, it was great. Through the binoculars, I saw a good mix, including Tanagers, Warblers (Redstarts, Yellow-Rumped, Yellow, Orange-crowned, Tennessee), several Towhees, Sparrows (Field, Chipping, Savannah, Song) and much, much more.

For those contemplating this kind of birding, it also helps to know your birds by song. I heard many birds I did not see, so keep your ears open. That means no mp3 players, which you should not wear while riding, anyway, for safety's sake. Who said you can't have fun by staying safe? And there is no sweeter music than bird song this time of year.

What do you do when you're stuck in a long line of traffic after work, barely moving and getting stressed out? I'll tell you what I do. I turn off into a Forest Preserve parking lot and go birding. That's what I did last night. What a great way to end the work day and, besides, it's warbler time here and like any hardcore birder, I do my best to make the most of the spring migration.

Of course, an emergency bird stop is something I'm always prepared to do, since I keep a spare bird guide, hiking sandals and change of clothes in the trunk of my car. I also typically have an optic of one kind or another in my purse. Last night, it was the excellent Nikon Premier LX 10x25 compact binocular.

Now, normally I don't like 10x compacts for this type of birding. Compacts, being lighter, are hard enough to steady and going to 10x just makes it worse. If you have the same problem, here's a little tip that will help. Hold your field guide at eye level, and use the edge of it to support the binocular. It may look a little odd to a passerby, but the extra weight and surface of a stout field guide like a Sibley's will do a nice job of taming the jitters.

So what about the warblers? Yes, plenty of action, though I arrived fairly late in the evening, so my list was a bit short. Yellow-rumped warblers, of course, were everywhere, but between the Yellow-rumps, I also picked up a Bay-breasted and a Tennessee. The bird of the evening, though, was the magnificent Scarlet Tanager, which put on quite a show for me (or, more likely, his intended mate). I will carry the vision of that bird for a long, long time.

Astronomers have always recognized the usefulness of binoculars for astronomy, but like many other products, tastes and preferences change over the years. There was a time, before the advent of "giant" binoculars, when the 7x50 was standard issue and many a fine old B&L 7x50 waited at the ready next to an astronomer's telescope.

A 7x50 is still a good choice, but in handheld astronomy binos, the move has been toward the 10x50. I suspect, the bigger is better thinking may be one reason. Hey, you can see more with a 10x than a 7x, right? Well, not really. In astronomy, 3x is insignificant as far as detail goes. I'm more of the theory that many of us have dismissed the larger exit pupil of the 7x50 as inconsequential. The larger exit pupil of the 7x50 may deliver brighter images under very dark skies and for very young eyes, but for most of us older, city bound astronomers under light polluted skies, a 10x does just as well and seems to be less affected by light pollution.

One of things I have always liked about astronomy with binoculars is that you don't need an expensive binocular to get started. Here at OpticsPlanet.net, we have many binoculars at $150 or less that will do a nice job. Here's a few that make Joani'e list. All of these 10x50s have the needed features for a good astronomy binocular as far as lens coatings and all offer plenty of eye relief for eyeglass wearers.

Bushnell Legacy 10x50

Celestron Oultand LX 10x50

Eagle Optics Triumph 10x50

Nikon Action Extreme 10x50

Oberwerk 10x50