The I3 eyepiece is used in astronomy in amateur telescopes. It's basically a real-time ccd imager that is vastly more sensitive than the eye, sells for around 2 grand. You can't use it during the day because it is too sensitive. Perhaps a reworked version could be used for daytime use. Anyhow these eyepieces (see link) dropped into astronomical binoculars would greatly enhance faint object detecion. It would be a pricey combination but interesting to try. Technically this isn't "more light" but it is a vastly increased efficiency in using the light that's already there and amounts to the same thing.

As far as conventional optics goes the exit pupil is a simple ratio. 10x40 binocs give an exit pupil of 4mm, or 40 divided by 10. So 20x80 binoculars would also give an exit pupil of 4mm. Now you've got more than twice the light gathering (due to pi-r-squared on the objective lens area) and twice the power, but the exit pupil stays the same. That satisfies your requirement of more light and the same sized exit pupil.

Looked at another way, 10x40s are also twice the aperture of 5x20s which are also available typically as opera glasses or pocket binoculars.

So my answer is

1. Yes, optical image enhancing is already on the market in specialize applications.
2. Without electronics, you can get more light through the same sized exit pupil by increasing magnification along with the diameter of the objective, and keeping the exit pupil ratio the same. 5x20s, 10x40s, and 20x80s are all on the market and all have the same exit pupil of 4mm. Try binoculars.com to see what's for sale.

As you change aperture and keep exit pupil constant your magnification increases (as in the three examples above). So the binoculars get harder to hold steady and to use without a tripod. The difficulty of holding the binocular steady is one reason why manufacturers tend to mess around with exit pupil (magnification).

Hope that helps,

GN

After the Recent Binocular “revolution”, How Do I Choose the Right Pair of Binoculars for My Needs?

The following is an article written to teach the customer basic terminology that is used when discussing the 21st century first binocular generation. This article covers the two most important groups of terms. The first group of terms or jargon involves the roof and porro prisms. The second of the two most important terms needed to learn to understand and to say are numbers rather than more words.  They are one small and one larger number separated by an “x”. An example is 8 x 32.  Read the article and both words and numbers will all be explained to your satisfaction.

When one speaks of a binocular “revolution”, the reference is to all the manufacturers involved in producing numerous different models of binoculars.  What happened and when?  18-24 months ago, several well-established and highly respected manufacturers involved in the use of optics decided to use current new technology and mix it with the basic binoculars of the time.  At that time, binoculars differed mainly by their manufacturer, the actual size of the pair of binoculars, and their price, which was manufacturer notoriety dependent.

Now prior to 2 years, the selection of a pair of binoculars was quick and easy.  Now, however, if a consumer decided to look for a pair of binoculars for their specific needs, their task can quickly and suddenly become an overwhelming one.  A consumer now has to have a background (such as given to them in this article) on the new generation of binoculars, so that their pick will fulfill their needs.

Customers are now faced with choices of manufacturers, models, and functional types with prices ranging from a low of $30 to highs in the hundreds and thousands of dollars.  The best way to handle all this information is to simplify it so that the pair you buy is the pair you need.  Once you set out to learn the new terminology or jargon used to describe these binoculars, you will realize how lucky you are to have this new generation available.

All current types of binoculars can be divided into two groups: the porro prisms and the roof prisms.

The models in the porro prism category tend to be the more traditional looking pairs of binoculars with their lenses offset, while appearing as wide as they are long.  These same models tend to be heavier and bulkier.  One very positive aspect of porro prism model design is that they tend to let in more light than their counter parts.  This extra light produces sharper and brighter images.

On the other hand, roof prism binoculars look like the connection of two straight tubes.  The designs are much newer allowing for production of more compact binoculars.  Their lenses can still be fairly large, similar to the porro type binoculars.  Due to their newer designs, even with large lenses, the physical weight and size of these binoculars can still be greatly reduced.  On the whole, roof prisms tend to be small and lighter weight binoculars as compared to the slightly older and heavier porro cohorts.  To repeat, porro binoculars tend to produce sharper and brighter images than the lighter in weight, and smaller in size roof binoculars.

The second important jargon used to describe a pair of binoculars involves numbers rather than words.  This descriptive language is written as one small number and one large number separated by an "x".  The first number on the left side of the x represents the number of time the object is magnified when viewing it through the lens.  The number to the right of the x represents the diameter of the objective lens, expressed in millimeters.  Therefore, the combination of 8 x 32 means the object appears to be magnified eight times while seeing it through a lens that is 32mm in diameter.

Therefore, when setting out to pick the binoculars best for you or as a gift, it is important to learn about and understand the two types of prisms and the meaning of the two number, separated by an x.  The first number to the left of the x represents the number of magnifications one sees the object while looking through the two lenses. The second number or the one to the right of the x represents the number of mm of the diameter of the lens. The higher the number to the right, the larger the lens diameter and the more light that can get through.  The more light, the brighter and sharper the image appears.  Unfortunately, the larger the diameter of the lens, the heavier and bulkier is the pair of binoculars, the more cumbersome it is to carry.

In an upcoming article, I plan on delving even deeper into the specifications that are used to understand and help the customer in finding that pair that will fulfill their needs best.

About the Author

Reed Oxman, the author of the above, is also creator and owner of the best place to purchase your needed Binoculars and Digital Binoculars , along with other types such as Waterproof Binoculars that you, your friends, or family may need. Bo rn and raised in California, he attended UC Berkeley Undergraduate, UC Los Angeles Medical School of Medicine and became Board Certified in Emergency Medicine and Pain Management.