Indicator Birding cc

Magnification:  The most common magnification sizes used by birders are between 7X and 10X. 10X is generally regarded as the largest magnification which is practical for hand held binoculars, although image stabilising technology may soon change this. 7X is considered weak by some, but is easy to use, and combined with a large objective lens, provides good performance in low light conditions. 8X or 9X is most popular among  birders, although many birders seem to like the power of 10X.

Size of Objective Lenses. The objective or "light gathering" lenses are important as they determine the amount of light that is received by the binoculars. 7X32 means that the objective lens is 32mm in diameter.  The amount of light the binocular receives is a function of the area of the lens rather than diameter. This means that 7X50 objectives gathers more than twice as much light as 7X35 lenses. The size of the objective lense affects both image resolution and performance in poor light conditions.  All  things being equal a 10X50 will provide better resolution than a 10 X40. To understand the value of the objective lens, divide the objective lens by the power: thus a 10X25 = 2.5 which is far poorer on this score than an

Field of view.  The wider the field of view, the easier it is to scan the terrain, and to pick up the bird, or hold a moving bird in your field of vision. A good choice is a 7X42 Wide Angle - you will enjoy the the very good 8.2 degree field of view that these offer.

Depth of field. The depth of field describes how much of the field is "in focus" at any one time. Binos with a poor depth of field require a great deal of attention to focussing in order to keep things in sharp focus. Naturally it is also a lot harder to pick up a bird, that you have not yet focussed on, if the depth of field is poor. Binos with a good depth of field make for easy birding and less concern to focus all the time.

Eye Relief. Eye relief is particularly important if you use glasses (spectacles), and describes the minimum distance between the exit lens and your eye. A long eye relief means that you can hold the binoculars further from the eye (with spectactles in between) and still get the full benefit of the binoculars.  A good eye relief figure is from 16mm upwards.

Size of exit pupil. The exit pupil size is the size of the pupil through which the light reaches your eye. In good light a 4mm exit pupil produces the same brightness as a larger exit pupil, this however changes in dim light, where the larger exit pupil provides a real advantage. A less obvious advantage of a slightly larger exit pupil is the ease of use. A small exit pupil requires precise alignment with your eye, and tends to be more strenuous to use, particularly if you are birding for long periods. A larger exit pupil is more relaxing to use.

Close Focus.  The capacity to focus on those warblers that come within four or five metres is a vital factor for good birding binoculars. Obviously the closer the better, but a close focus of 10 feet is desirable if you are short-sighted !  For Southern African bush birding I would not recommend binos that have a close focus of greater than 16 feet.

Weather-proofing. Weather proofing varies from "full weather proofing" to shower proofing to no weather proofing at all.  Of course fully nitrogen-purged and sealed binoculars are ideal, but come with a hefty price tag.  For South African conditions full weather proofing is not generally necessary, and many of the better quality mid-range binoculars provide adequate shower proofing. This does of course mean that care must be taken in rainy conditions, and that the binoculars may have to be nursed in very wet conditions by storing them with a silicon dessicant.  If you are going to be birding in rainy conditions make sure you get a pair with a rain guard for the front lenses.

Type of lenses and lens coatings. Special coatings on the various lenses found in binoculars are aimed at reducing reflection, and it is here that the greatest advances in image quality have been made.  Cheaper binoculars usually have coatings only on the external lenses, while better binos have coatings on all lenses. Single coatings on a lense reduce light loss to 1.5 % from about 4% for uncoated lenses. The best multicoatings achieve a figure of less than 0.5% per lens. Considering that a pair of binoculars typically has more than 10 lense surfaces the difference between "fully multicoated" and "coated" can be quite substantial ! With advances in technology, some binoculars in the R1500-2000 range are now fully multicoated, while formerly only the very best brands had this feature. I would recommend fully multicoated lenses for birding binoculars. Look for the label "fully multicoated" and "BAK-4 prisms" to indicate quality coating.

Key Choices : Magnification, Style and Price

1. Binocular Magnification: choosing between a 10X or an 8X

This is one of the most common choices that binocular buyers have to make.  Obviously one should get a better, more magnified view with a 10 power binoculars. In reality, the larger magnification is more difficult to handle, and it is doubtful whether even experienced birders actually see more through the more powerful pair.  In general I would recommend that beginner and intermediate birders go for 8 X power binoculars, as 10 power requires more skill and are often more difficult to use!

The key issue is quality and the diameter of the objective lenses. All things being equal, a 10X50 will provide better image sharpness then a 10X40, as it gathers more light. A top of the range  8X32 will provide a better, clearer image than most 10X binoculars will,  quite apart from the ease of use and the stability of the image you are seeing.

8X32 and 10X40 have about the same magnification to objective lense ratio and are generally regarded as the standard, or minimum for birding, where one generally needs good light gathering ability. Nevertherless a 10X50 or 8X42 will, all things being equal, provide a better image, and are popular among birders willing to carry the extra weight. In addition these binoculars may also offer a wider field of view, which some birder regard as important, as it allows one to pick a bird up more easily.

Porro vs Roof Prism. Roof prisms are generally highly rated, and more expensive than the simpler porro prism design. Zeiss, Leica and Swarovski made the roof prism famous by producing the best high quality binoculars in this format. The weight advantage, compact and durable design and the elegant shape of roof prisms has contributed to making them almost universal among top birders. In fact the roof prism design is not as good optically as a porro prism design of the same specifications. In practise this means that you can get the same quality view at a lower price by going with porro prisms. Manufacturers such as Bushnell, Nikon, Meade, Swift and Celestron have all produced excellent Porro Prism binoculars which offer excellent optical quality at a fraction of the price of the top roof prisms from Swarovski, Zeiss, Leica and Bausch and Lomb.

The key choice: How much is worth paying ? ?

This depends on how important birding is to you. Very good binoculars are availabe in the price range between R3000-5000, while you can get by with entry level binoculars for under R1000-00. You will probably soon get frustrated with these however, especially when you look through somebody elses top-range binoculars. My advice is, get the best binoculars money can buy. Pentax, Nikon, Leupold and Bushnell are some manufacturers offering very good binoculars at mid-range prices.

Here are some models you may take a look at (Current approxiamate SA prices in brackets)

Pentax 8X42 DCF HRc (R3,600)
Bushnell H20 Roof Prism 8 X 42 (R2,400)
Bushnell H20 Porro Prism 10 X 42 (R 2,100)
Nikon 8X25 Travelite (R1,230)
Nikon 8X40 Action EX (R2,100)
Nikon Monarch 10x42 (R4,000)

One good place to buy Binoculars in Gauteng is Photoweb SA

The very best Binoculars

Once the bug has really bitten, you may find your hobby so compelling that you don't want to take any chances with a less than optimal view of a bird you may see. The appeal of the really great binoculars is that you see more very far, more very close and more in dull light conditions: If you want to really get serious about birding, and are willing to invest in your hobby, then one of the top three binocular makes will find a home around your neck! Here they are: (in Alphabetical order)

Leica Ultravid HD

Very sharp image with brilliant, true colours. These binos are superbly engineered and with the best diopter adjustment mechanism of any binoculars. Swarovski EL

OMy pesonal favourite: Optical quality is unbeatable and a unique design makes them easy to hold and focus, even with one hand. Outstanding color fidelity. Sharp from edge to edge. Have a superb 30 year guarentee, and in my case they came back better than new! The 8.5 X 42 is a very good option. Zeiss 42 Victory FL

The Zeiss Victory FL has won much acclaim, not least because it focuses the closest, excellent for close-up bush birding and if you are watching drafonflies and butterflies. Rated tops if you wear glasses