AOE 11 x 70mm Binoculars
For Fathers Day 2008, I got a pair of binoculars. My wife suggest the idea but I did the research and picked the pair I wanted out.
Most people buy binoculars by going to their local camera shop, looking at the range of 5 or 6 pairs they have on the shelf and choosing based on factors like physical size, magnification and the price of the pairs in front of them. I think this is a really bad way to buy binoculars. Camera shops are the possibly the single most expensive way to binoculars and their range is usually limited to compact sets with medium to large magnification and small objective lenses. Finally, the staff usually don't know very much about binoculars.
Exit Pupil
The main features I was initially looking for was, high magnification but I was also interested in good low light performance as well as the best price I could get. To get good low light performance binoculars need to have a large “exit pupil” figure. The exit pupil is the size of the hole of light coming out the binoculars after they have done their magnification work. It's very easy to calculate the exit pupil of any pair of binoculars. You just take the objective lens size, in the case of my binoculars, 70mm, and divide it by the magnification, 11 in my case, to get an exit pupil of 6.4mm.
To understand if this 6.4 mm exit pupil is good or not we just need to compare it with the size of the pupil. In the dark, a young persons pupil will dilate out to about 7mm. A person my age, 37, might get to 6mm and someone in their 60's might only get 5mm. My binoculars are indeed very good in the dark. The 6.4mm pupil means that using them is about the same thing as moving to 1/11th the distance of what ever you are observing and looking at it with your own eyes.
Compare this with a compact pair of binoculars rated at 10 x 25. The exit pupil would be 2.5mm. This is about as small as the pupil can go in a bright daylight. These would be fine for watching the tennis during daylight but not very good in the evening or night nor for watching flood lit sports events as every thing would appear rather dark and lacking in colour.
Magnification
Magnification was another consideration for me. The consideration for magnification is stability when hand holding the binoculars while still getting the best view possible. 10X magnification is considered the maximum you can have and still be able to hold them steady enough to view the detail of your subject. I consider the 11x magnification of my AOE binoculars too much to comfortably study the moon and stars hand held but its just fine for plane spotting or watching sports. I had the option to get 15x magnification for no extra cost with the same sized objective lens and I chose the smaller magnification for exit pupil reasons not stability. Now that I have the binoculars I am particularly glad I got the 11x's for the hand held performance because the 15x would be unusable for most hand held work.
Price
I paid $160 including delivery for my 11x70's from AOE. I haven't seen similar binoculars to mine in the shops but I did recently see a pair of 20x80's in a window for $900 at one photography store. AEO sell a set of 20x80's for $200 delivered. For someone looking for a good pair of cheap smallish, but not compact, binoculars might consider the AOE 7x35's for a mere $49. The biggest binoculars you can get are the 30x100's which go for a very reasonable $450. These babies are huge, 50cm long and 5kg in weight. You can't hand hold them steady enough to look through them effectively so you will also need the $20 metal tripod adapter and possibly a tripod if you don't already have one. Even so, buying binoculars online still represents a considerable savings over buying at the local camera store.
Quality
The visual quality and performance of these binoculars is really quite good. It is surprising how much extra can be seen compared with the naked eye, particularly at night. A far off aircraft that appears as a single slow moving light, then observed through the binoculars, can be seen as a pair of white headlights with a red and green wing light clearly visible. With closer aircraft, its possible to make out the brand from the light of the navigation lights shining on the livery.
The night sky also gives impressive results. Dozens of stars that are just not visible to the naked eye appear when looking through the lenses. When looking at Jupiter, the moons can be plainly seen. It makes you feel a bit like Galileo when you observe that they change position each night. Orion's sword, that appears as 2 stars to the naked eye actually has 3 pairs of stars with the Messier 42 nebula visible as a cloudy smudge.
Daylight viewing is very good but probably not any better than your average set of 10x50s or even 7x35's. But it is noticeably better than my parents compact pair of 10x25's with the image being clearer and colours brighter. Through the smaller binoculars, the colours appear a little washed out and detail tends to be a bit fuzzy.
Size
One import consideration about these binoculars is their sheer size. They are 30cm long and weigh about 2.5kg. When you use them in a public place, you may find that people stare as most people have not seen binoculars this big. You definitely need to plan ahead if you are going to take them somewhere like the tennis or a concert as they will constitute a large portion of your luggage. These will make even a pair of 10x50's seem discrete and manageable.