February 2015

Tony Martinez

                                      Tony Martinez

Each month I will describe sights of interest in the night skies of South Carolina. These sights will be broken down into three sections; what you can see with the naked eye, with binoculars, and with a small telescope. The best time to view the night sky is at and around the times when the Moon is not visible, what is known as a New Moon; which will occur this month on February 18th. For February, your best viewing nights will be from February 11th to the 21st. The Star chart below is set for Florence, SC on February 15th at 9 pm.


At various times I like to repeat topics from earlier columns. These are topics that I feel are important to the hobby of astronomy, and it is therefore important that new readers to this column are aware of these subjects.

This month, I will repeat, with some modifications, the topic of big binoculars.

 Big Binoculars:
As I have mentioned in previous columns, a good way to begin a hobby in astronomy is to use binoculars. Some of the reasons are: they are light weight, easy to use, and relatively inexpensive, can be used for other things besides astronomy, objects are right side up and not reversed, and you can see a large area of the sky. One downside is their limited useful power. A handheld binocular is only useful at 7-10 power; above that, normal hand shake makes viewing difficult. The downsides of telescopes are: they are not light weight, therefore not very portable, not always easy to use, can be expensive, and usually cannot be used for things other than astronomy; also objects may be upside down and/or reversed.

In the quest to enjoy the night sky, most amateurs totally neglect the use of “Big Binoculars.” Big binoculars usually range from 15 X 70mm to 40 X 100mm in size, but can be even larger. All the benefits of binoculars are retained, with some limits on portability. The price will also increase as the size increases, and all big binoculars require a tripod. The image below shows a selection of various binoculars. Moving right to left, the smallest is a 35 mm binocular, followed by two 50 mms, then a 70 mm, and on the far left, 25 X 100mm binoculars.


In reality, a binocular is just two refracting telescopes attached side by side. However, there are two main advantages of big binoculars over using a refracting telescope. First, the images are right side up and not reversed. Second, they give better views. Concerning better views: One cold winter evening several years ago I was out viewing the Orion Nebula, M42, at 25 power through a Schmidt-Cassegrain reflecting telescope. Out of curiosity, I pointed my 25 power binoculars at M42; the result was striking. The images shown below give a good approximation of what I saw that night.

Tel and Bino 2

The striking difference in the views is due to the ability of the brain to better process images from two eyes versus one eye, and not the fault of the particular optics of the two instruments. That incident led me to redirect my hobby to becoming a binocular astronomer. Although I still use my standard telescopes, almost all of my astronomical viewing is done through “Big Binoculars.”

Below are photos of my two big binoculars. Both are 25 X 100mm as shown, however, the binoculars on the left have 45 degree viewing, and interchangeable lenses, and the binocular on the right is straight through viewing, with a fixed 25 power eyepiece.

Two Big Binos 2

If you decide to venture into big binoculars, on the low price end, 15 X 70mm, 20 X 80mm and 25 X 100mm are priced from about $80 to $350. The only required accessory is a tripod, and these binoculars can easily be placed on a good standard photographer’s tripod. The second accessory is not required, but is on my “must have list,” and that is a Red-Dot finder. Again, if you note in the above photos, both binoculars have Red-dot finders attached. Once you start viewing through 25 power binoculars, you will find it somewhat difficult to aim them; sometimes to the point of frustration. These simple little finders will make using big binoculars a joyful experience.

If you have more money available for this hobby, then you may want to invest in a 45-degree viewing binocular with interchangeable lenses; seen on the left image above. However, this will bring the price up to about $1000 to $2000. From my personal experience, the 45 degree viewing aspect is much more important than the ability to increase your power. The reason is that when using a straight through big binocular on a simple tripod, it is almost impossible to view objects above an angle of 50 to 60 degrees; thereby missing a lot of sky. My solution was to just stay up later until the object of choice moved lower and into my range of view, or to look for selected objects at a different month of the year.

In addition to the simple tripod mount, there are other mounts for big binoculars, as is shown below.

Family Binos

If you like to build things, the mount options will increase.

Three Chairs 2

And finally, if you decide to invest heavily in binocular astronomy, you will probably opt for the set up below! The big binoculars shown in the image below are 25 X 150mm. These big binoculars are used by amateurs to discover new comets, such as the comet Hyakutake in 1996, which was 100 million miles from Earth when spotted with these binoculars.

Hopefully, ScienceSouth will have these binoculars available for public viewing later this year. (But not the chair)


Naked Eye Sights: Venus in the west and Jupiter in the east, and the beautiful Orion constellation.

Binocular Sights (7 to 10 power): Jupiter and its moons. The Pleiades cluster. The Orion nebula.

Telescope Sights (60-100mm): Jupiter will be at its best this month.

See you next month!

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