Choosing a binocular

2013, last modified 12-5-2014


Some thoughts about "which is the right binocular for me?"

1. 8x magnification for handheld

I am convinced that an 8x magnification is the best compromise for a stable image and good resolution power.

2. Small is beautiful: 8x30/32

The best binoculars are useless if you leave them at home. 8x30 and 8x32s are the smallest high quality binoculars. You can always take them with you and with an exit pupil of 4mm they already reach far into darkness. 8x40 is better if you often want to explore the twilight, but will be more expensive and heavier - probably too heavy for everyday. Plus, the 8x30/32s generally have a wider field of view: For example:
Zeiss Conquest HD 8x42: 128m
Zeiss Conquest HD 8x32: 140m

And nothing beats a good wideangle...


3. Wideangle: More emotion, easier use

A good wideangle binocular just drags you into the image. It´s about transparency, like looking through an open window vs. looking through a tunnel. It´s about more emotion in viewing. But also about an easier tracking of moving objects and better orientation within the image.

Here is a small comparison, fields of view in 1000m distance:

Swarovski Habicht 8x30: 136m
Nikon 8x30 EII: 154m (!!!)
Nikon 8x32 SE: 131m
Zeiss Conquest HD 8x42: 128m
Zeiss Conquest HD 8x32: 140m
Minox BL 8x42 Made in Germany: 113,4m
Zeiss Victory HT 8x42: 136m
Zeiss Victory FL 8x32: 140m
Swarovski EL Swarovision 8x32: 141m
Swarovski EL Swarovision 8x42: 133m


4. Cheap means: tunnel view.

Almost all cheap and a lot of middle class binoculars have a tunnel view. A small field of view makes the production of a decent binocular much easier, and helps to keep volume down. For example, the Minox BL 8x42 Made in Germany and its Olympus counterpart only show 113,4m/1000m compared to the at least 130 meters I would expect in a good middle class bino. And the cheap porro designs even less. Some exceptions like the Nikon Action EX 8x42 have a wideangle design, but a horribly distorted, unsharp image. Cheap and good wideangles do not exist (same applies for photography).


5. Which price to go for?

If you have the money and a desire for viewing the world with real pleasure, a top binocular of one of the best manufacturers will be a good investment. Unlike most electronic devices, top binoculars keep their value for many years, and unlike luxury items, you are not mainly paying for a name but get a robust and refined tool. I use my binoculars almost every day, and mostly with a smile on my face. Nice dividend. I understand that like all great optics great binoculars cannot be built cheaply.

For many people a good middle class binocular (400 -800.-) is preferable. Some of these, like the Swarovski Habicht 8x30 or the Nikon SE 8x32 are reference class in some aspects and belong to the "greatest binoculars" ever built. You will get most out of your money ("law of diminishing returns"), and you don´t have to worry for safety so much.

Binocular fans may tell you - Holger Merlitz does so here - that the old fashioned porro designs have a lot of advantages, most notably a much more threedimensional image than the modern slim roof designs, and give you a highend image quality at an affordable price. I love porros, because I live in a 3D world, and want to have 3D in my binocular images, too. Many of my favourites are porros. Their big disadvantage is eyestrain in very close focusing, say below four meters - the eyes squint more than in roof designs.

A tripod and tripod adapter will boost your middle class binocular´s performance considerably. And if you go for the best of the best, you will want those, too - to really enjoy the full capacity of your investment. Without tripod, the difference between good middle class and top end are often smeared by image shake

6. Get a good SAMPLE

I´d recommend you do this simple collimation test with your new binocular. You will know quickly if the central quality for a good performance is there. Excellent center sharpness tells you nothing about collimation. Your eyestrain will.

Most cheap binoculars are shockingly bad. You will need a lot of patience to find a sample worth keeping. Order one, send it back, order the next one. Or order three, send back three, than give up and choose one from the middle class...

In the middle class, variance will be smaller, and even smaller in the top class. That means: Much less risk and hassle for the buyer! As I am passionate about optics, I always try to pick a cherry, that is a sample that is from the upper third of the production tolerance.

Test your sample thoroughly before deciding to keep it.


7. Diopter adjustment

With a new glass I do diopter adjustment carefully a couple of times (focus with left eye on a well defined object not too close, then open right eye and adjust diopter for optimum image) and settle with the most frequent result. Together with that I also check both lens systems seperately - are they both sharp, and resolve well everywhere in the field?


8. Eye relief and sweet spot for ease of view

Eye relief is the maximum distance between the ocular surface and the point from which you can see the full, unvignetted image. Most modern binos have quite a large eye relief to make them usable for everyone. I have a feeling that there is a sweet spot for using a binocular where I have the full field of view and the least blackouts. I adjust the eyecups accordingly - well, mostly I fix some rubber foam instead - so I automatically have the best ease of view.


9. Is it really good?

Generally, a good binocular really recommends itself:

- It´s transparent (like looking through an open window), there is no eyestrain after long watching, it has an immediate "wow" effect.

- You will find focus quickly and safely, without playing around with the focusing.

- You will find diopter adjustment quickly and with little doubts.

- There is little flare or ghosting watching against the sun or with high contrast in the scene. This is a often a weak spot even of top models.

- Eye relief has to be large if you wear glasses.

- Try the binocular in lowlight situations so your pupils are open and use the weakest performance of the binocular. On a bright midday, a lot of binoculars look ok because your pupils close and correct optical deficiencies of the glass (by blocking the peripheral lightrays). Although some argue you should test the binocular with the maximum performance of your eyes to really see its weaknesses - which will be in bright light.

The key point is: You really have to COMPARE binoculars to find and appreciate one worth of spending your precious time with. You might start in a shop, but it´s much better to have a couple of weeks to do a thorough evaluation of pros and cons.