Whenever somebody recommends an item for you, that recommendation is likely tainted with some level of bias due to personal preferences, experiences, and needs. No item encapsulates this rule better than binoculars.
No human eye is the same; every single one is slightly different from the next in size, shape, and even the colors that we perceive.
Your eyes might be entirely different from the eyes of your friends, meaning that a product that works for them might not work for you- their recommendations may be useless.
The best way to decide on any product, especially when in comparison with another, is to look at its available features. This rule goes doubly for binoculars.
Read on to learn everything you need to know about the differences between these two varieties of the Terra ED model from Zeiss. The difference is more than just the numbers in their name!
By the time you’ve read everything, you should know just what model will work best for you!
What are the Terra ED 42mm Binoculars?
Zeiss is a manufacturer of premium binoculars- that is to say, many of them are expensive. For the most part, Zeiss binoculars cost over $1,000, with only a few models dipping into the $900 price range.Â
One day, Zeiss decided to expand their price range and dip their toes into cheaper territories. This idea birthed the Terra ED, a $499.99 set of premium binoculars from the binocular experts at Zeiss.
However, the Terra ED coming at almost half the price of Zeiss’s next-cheapest model raised some red flags. Did Zeiss cut corners somewhere? Many rival manufacturers certainly seemed to think they did.
Is it possible to make a high-quality set of binoculars for such a ridiculously low price, like the one that the Terra ED boasts?
Ultimately, some people seem to think so- and consumers love the Terra ED, especially in the 42mm series. Let’s take a closer look at this model.
Â
Glass and Glass Coatings
One of the most vital features of any binocular is the coating of its glass lenses. Binoculars without any coatings lack many protective features and may offer subpar imaging that results in a blurry or low-quality visual.Â
The ‘ED’ in the Terra ED’s name stands for extra-low dispersion, regarding the type of glass Zeiss puts in the lenses of these binoculars. Let’s take a closer look at what that entails.
Â
Extra-Low Dispersion glass
The term extra-low dispersion, which many manufacturers and binocular enthusiasts refer to as ED, refers to the dispersal of light through a piece of glass- similar to how a prism works.
When light enters a glass, the lens will disperse it in unique directions because light wavelengths differ in behavior. A simple prism experiment helps to prove this fact.
Extra-low dispersion glass features trace heavy metal elements to prevent dispersal and keep light together as much as possible, producing a higher-quality image in your binoculars.
Extra-low dispersion glass helps prevent color fringing when you focus on bright, shiny, or contrasting objects.
Occasionally, manufacturers will use ‘HD’ in their model names to denote extra-low dispersion, also known as high-density glass.
However, this practice can be disingenuous and stand for high definition when there is no true way to guarantee an HD image. There is no existing standard for image quality in binoculars.
On top of the excellent ED glass that Terra ED binoculars use, Zeiss has imbued these lenses with its signature multi-coating, also known as MC. MC helps keep your lenses safe and produce high-quality images.
All varieties of the Terra ED utilize these ED glass lenses, so no matter if you buy the 10x42 or the 8x42, you know you’re getting a pair of high-quality lenses to keep your binoculars operating smoothly.
Optic Properties
When it comes to the characteristics of the Terra ED’s visuals, or the optics themselves, the Terra ranks average among binoculars at the very worst.
 However, at their best, they’re slightly above the average line for most binoculars. For a cheaper model from Zeiss, this middling range is to be expected.
 If you want high-quality performance and top-tier optics from your binoculars, you should shell out the extra cash for a higher-end, more prestigious model.
Field Of VisionÂ
The Terra ED 8x42 features a field of view that measures 375 feet at 1000 yards out. This range is slightly above average when you compare it to a traditionally full-sized, 8x42, roof prism set of binoculars.
On the other hand, the 10x42 variety of the Terra ED comes in at a perfectly average field of view for its size and prism classes. At 1000 yards, you get 330 feet of vision from the Terra ED 10x42.
Close Focus Distance
Every set of binoculars has a minimum distance that they require to focus properly. This distance is known as the close focus.
For the Zeiss Terra ED, both in the 8x42 and 10x42 models, the minimum close focus is 5.3 feet.
At 5.3 feet, the Zeiss Terra ED has a perfect minimum close focus for birdwatchers everywhere. However, birdwatching is not the only benefit of this close-focus distance.
As we have previously established, the Terra ED line utilizes roof prisms. As a whole, roof prism binoculars have a close focus of around 6 feet. This distance puts the Terra ED models significantly above average for their prism class.
Visual Clarity
As an overall trend, the visual quality of the Terra ED line is pretty good at its absolute worst.
When you compare it to the rest of Zeiss’s available models, you might find it lacking- however, you should remember that the Terra ED models are around half the price of Zeiss’s usual offerings.
When you compare the Terra ED to offerings from other companies, particularly in its price bracket, both the 8x42 and the 10x42 models are notably competitive in terms of picture quality.
There is no clear victor between the 10x42 and the 8x42 in this department- they both have excellent visual clarity.
Â
Other Optic Properties
These binoculars are far from superb, but they are solid pieces of equipment. The ED lenses provide a neutral color palette without any bias from tining.
Brightness levels are more than simply acceptable, the depth-of-field is stunning, and the focusing process is extremely smooth.
When you’re looking at visual clarity and other optic properties, the 10x42 and the 8x42 are evenly matched.
Â
Physical Properties
Despite the difference in magnification levels, the Terra ED models all look similar to each other.
All feature a compact frame and a similar size; 5.5 inches tall with the eyecups folded down, or 5.9 when the eyecups are at full length.
However, their size and frame is not the only physical aspect to note.
Â
Weight And Balance
With its included rain guard and lens caps, the 8x42 Terra ED weighs in at 26.3 ounces. Within the same parameters, the 10x42 Terra ED weighs 26.1 ounces.
Those .2 ounces don’t feel like much, but when you spend an extended period holding your binoculars, they can make all the difference. Therefore, we think the 10x42 gets an extra point for being lighter.
Eye Relief
In the 8x42, the eye relief- or the distance between your eyes and the ocular lens- is 18mm. In the 10x42 model, it is 14mm.
Adjustable Features
The diopter adjustment on the Terra ED line is somewhat primitive, consisting of a twistable rubber ring just below your right-hand lens.
The diopter adjustment does not feature any sort of marking and is prone to drifting as it does not lock. This bare presentation means that the Terra ED line can lose any special diopter requirements, so you might want to specially mark them yourself.
Protective Features And Casing
Any good binoculars come with extra goodies for you to use.
 The rain guard included with the Terra ED is particularly useful, with a flexible pair of rubber cups joined by a rubber link. This guard fits perfectly over your eyecups.
The Terra ED also comes with an included neoprene strap that you can feed through brackets on either side of the rain guard to keep all of your pieces together.
The case is not particularly protective, as it is a velvet drawstring bag. It can certainly keep your binoculars clean, but if you drop them, they may sustain some damage.
Thankfully, Zeiss does make a traditional case for their Terra ED line if you prefer to travel a more secure route.
Conclusion
Unfortunately, you can’t easily tell somebody that one binocular is better than others in its price range. However, with the Zeiss Terra ED, it might be easier than you think.
Both of the 42mm models in the Terra ED line are exceptional binoculars and have plenty of similarities.
Ultimately, the decision falls to this- how much magnification do you need, and is it worth sacrificing a small amount of your field of vision?
Nobody knows your needs better than you do, so, unfortunately, you will have to make this decision on your own.
Look over the available details and decide which binoculars best meet your needs!