7×50 binoculars are typically recommended for marine viewing, but is this size versatile enough to use for bird watching as well? If you are keen to find a pair of binoculars that work equally well for ocean use as land use, 7×50 could be a viable option.
There are some key features that make 7×50 binoculars good for bird watching:
- The field of view on the 7x50s is relatively wide.
- The 50mm sized objective lenses gather lots of light.
- The 7x magnification is easy to use.
- Their exit pupil is a forgiving size.
- This configuration tends to be moderately priced.
In this article we’ll go into more depth about why each of these features benefits bird watchers.
To get a balanced view, we will also consider the downside of this size of binoculars.
What are the advantages of 7×50 binoculars for bird watching?
Let’s take a closer look at some of the ways in which 7×50 binoculars can be suitable for use as birding optics.
Wide field of view
When a pair of binoculars boasts a wide field of view, it means that you can see a broader section of the landscape in front of you.
Seeing a broader view makes it easier to spot birders within that landscape. Then when the bird starts to move, or if you are tracking birds that are already on the move, a wide field of view helps.
Beginner birders will find it especially helpful to have binoculars with a wider field of view.
Light gathering capabilities
The number 50 indicates that 7×50 binoculars have objective lenses (the wider end, furthest from the eye) that measure 50mm. This large size means that the lenses let more light than, say, a pair of 8×42 binoculars, with objective lenses of 42mm.
The more light that enters the binoculars, the brighter the resulting image that reaches your eye, at the ocular lens. Brighter images translate to more detail and sharper views, which is what most birders are looking for.
User friendly magnification
The ‘7x’ denotes that the binoculars magnify the object seven times larger than you would see it in real life. In terms of optics, this is a moderate magnification.
Many bird watchers, for instance, choose 8x binoculars. If you are interested in exploring the pros and cons of each size of magnification, we cover the topic in more detail here – 7x vs 8x binoculars: which work best for birding?.
To understand the main reason why a lower magnification often offers a better view we need to mention image shake. Even though you are holding your binoculars as steady as possible in your hand, there will be inevitable movement.
This movement comes from the natural motions of your body, like breathing, heart beats or tremors. Outer environmental conditions may also affect or exacerbate this, like windy conditions, loose gravel, sloping ground, for example.
Any unsteadiness shows up in the image and, when the magnification is greater, the shaking is also increased. This means that the resulting image may be less clear and sharp at higher magnifications like 8x or 10x than at 7x.
Large exit pupil is easier and more comfortable
The exit pupil on a pair of 7×50 binoculars is 7.1mm. This is quite wide, especially in comparison to 8×42 binoculars that have an exit pupil of 5.3mm.
With an exit pupil over 7mm, the 7×50 binoculars will offer a bright view in lower light conditions than the 8x42s.
In fact, the view will be just as bright as if it were seen without binoculars. This is because the 7mm measurement matches the pupil diameter of the human eye, which dilates to compensate for the lack of natural light.
For a clear and detailed explanation of exit pupil, feel free to refer to this article: What does exit pupil mean in binoculars?
Attractive pricing of 7x50s
7x50s are often available as the Porro prism style of binoculars. Typically, these cost less than roof prism binoculars.
So the lower price of 7×50 binoculars makes them attractive for those looking for affordable options. If you are looking to invest in just one pair of binoculars fit for marine use and to get started for birding, 7×50 could suit both scenarios.
What are the cons of 7×50 binoculars for bird watching?
Due to their larger objective lenses than say a pair of 7x35s, the dimensions of 7x50s will be longer, wider. They will be more bulky to pack and carry around your neck.
Since the 50mm lenses require more glass the 7×50 binoculars also tend to be heavier than other configurations.
Though 7×35 or 7×42 binoculars are smaller and lighter, their smaller objective lenses will not have the same light-gathering capacity. Similarly, their exit pupil will be narrower. Therefore their images will be dimmer.
Final thoughts on whether 7×50 binoculars are good for bird watching
The reasons we’ve discussed make 7×50 binoculars highly recommended for marine use, when the motion of the boat on the water makes it difficult to hold any binoculars still in front of the eye.
The wide exit pupil is especially helpful in low light because it gives a brighter image. With a large exit pupil, the binoculars are also comfortable to use because it’s easier to get your eye in the sweet spot behind the ocular lenses even on a moving vessel.
When you are on a boat, it is by nature, more unsteady. So to avoid a blurry view, the priorities for marine binoculars are the lower magnification in combination with the larger objective and exit pupil diameters.
Though this size is the classic recommendation for use on the ocean, the characteristics of 7x50s can prove versatile enough for bird watching.
Wide 50mm objective lenses allow in plenty of light, so the binoculars perform well at times of the day when there is less light, or in darker weather conditions.
How 7×50 binoculars can suit birding
The moderate magnification of 7×50 binoculars, combined with the wide field of view, makes it easier for birders to locate and track birds.
Their lower price point also means they are good as an additional pair of binoculars, or as entry-level optics. As they are mainly available in a Porro prism design, they can be a good option for fans of this more traditional style of binoculars.
While some birders find that the heftier 7×50 binoculars are easier to hold steady, other people may find the extra weight and bulk add up to a disadvantage.
This is one factor influencing why binoculars with slightly smaller objective lenses, like 42mm, tend to be more popular for general birding purposes.
Binoculars with objective lenses in the range of 40mm to 44mm are just that bit more portable, while still maintaining reasonable light-gathering sized lenses.