If you’re new to watching stars the variable called eyepiece size can be quite misleading. You’ll hear long debates between eyepiece sizes like 1.25” or 2 inches.
Some will say 2” eyepieces are premium. Others will say 1.25” are more adaptable. So, it’s quite easy to get confused over it.
So which one is better between 2 vs 1.25 eyepieces?
Both 1.25” and 2” eyepieces have their own strong sides. What matters is what you’re expecting from your eyepiece. If it’s a wide field of view then 2” eyepieces are superior to 1.25”. If it’s magnification then 1.25” eyepieces are what you’re looking for. They’re also cheaper than 2” eyepieces.
That’s the preview of our discussion for today. If you’d like to know the details then join us on this journey.
A Quick Overview: 2 Vs 1.25 Eyepieces
Before a heated discussion, we’d like to present you with a quick comparison. The table here shows the fundamental distinctions between 2 inch eyepiece vs 1.25 eyepiece.
| Aspects | 1.25 Inch Eyepieces | 2 Inch Eyepieces |
| Physical Size(Diameter) | 1.25 inches, Smaller | 2 inches, Slightly bigger |
| Weight | Lighter | Heavier |
| Focal Length | Short | Long |
| Magnification | High/Mid-range | Low |
| Field Stop | Smaller | Bigger |
| Field Of View | Smaller | Wide |
| Eye Relief | Good | Better |
| Coating | Good | Better |
| Cost | Cheaper | Expensive |
Now that you’ve seen the basic dissimilarities, let’s talk about them in more detail.
Detailed Comparison: 2 Vs 1.25 Eyepieces
Clearly, a short overview isn’t enough to understand all about eyepieces. To compare both you’d need to know in detail about all the aspects of it. Hopefully, our next sections will help you guide through.
Physical Size
The first dissimilarity to notice between 2” eyepiece vs 1.25” is the physical size. 2” and 1.25” imply the diameter of the eyepiece’s barrel. 1.25” eyepiece diameter is visibly much smaller than 2” eyepieces.
Compared to 1.25 inch, 2 inch eyepiece is of massive size. It’s also heavier and has more lenses. the 1.25” eyepiece is much lighter and easier to move.
They are also adaptable to most telescopes without any need for an adapter. Sometimes you’d need an additional adapter to fit a 2” eyepiece to telescopes.
So, in the case of physical size, 1.25” eyepieces are slightly better.
Winner: 1.25”
Here’s our recommendation for some of the best 1.25” eyepieces out there.
| Image | Product Name | Key Feature | Price |
|---|---|---|---|
  | SVBONY SV135 Telescope Eyepiece | 1. 7mm-21mm adjustable focal length 2. Comfortable eye relief for eyeglass wearers | Grab From Amazon |
  | Celestron - Zoom Eyepiece for Telescope | 1. 8mm-24 mm focal length 2. Compatible with all 1.25 eyepiece telescopes | Grab From Amazon |
  | Gosky Telescope 1.25" | Specialized for daytime viewing plus planetary observations | Grab From Amazon |
Field Of View & Magnification Power
The real difference behind the 2” and 1.25 eyepiece lens isn’t about the optical quality. Rather it’s about the difference in the field of view and magnification power.
2-inch eyepieces have a wider range of field of view than a 1.25” eyepiece. It also comes with a lower magnification power than 1.25 eyepiece magnification.
For example, a 2” eyepiece of 30mm focal length would have FOV of 82 degrees. With the same focal length, 1.25” eyepiece will have a FOV of 50 degrees. The difference is bigger like how 10×50 and 20×50 binoculars would be.
2” eyepiece magnification is suitable for watching bigger objects in the night sky. If you want to see cosmic nebulas or clusters then a 2” eyepiece is better.
If you want to go for higher magnification than 1.25” eyepieces are better. Watching smaller objects would be easier in 1.25” eyepieces.
Winner: Depends on user needs
Focal Length
2-inch eyepieces are mostly built on long focal length. You’ll find 2” eyepieces even in bigger focal lengths than 40mm. Because with a long focal length you’d get lower magnification power.
However, it doesn’t necessarily make cosmic objects brighter. A 1.25” would rather give a brighter image than 2” eyepieces. This is a characteristic that you’ll find in 10×50 and 15×70 binoculars.
Some manufacturers now offer 2” eyepieces with a short focal length. They also have a wider field of view. Which is a good combination for the astronomers.
1.25 eyepiece for telescope are built on rather short focal lengths. Also, 2” eyepieces are designed to have wider FOV.
So a longer focal length is suitable for these eyepieces. As 1.25” eyepieces are of high to mid-range magnification they’ve shorter focal lengths.
Winner: 2’’
Here’s our recommendation for the top 2” eyepieces.
- For stargazing at nights, you can’t get better than Televue 31mm Nagler in terms of contrast and color.
- Explore Scientific 68 Degree 28mm– Compact view factor and sharp field of view.
If you don’t wanna be bound to a single focal length, you can opt for the Celestron – 2” Eyepiece and Filter Accessory Kit. It comes with focal lengths starting from 26mm to 40 mm.
Cost
A 2 inch eyepiece for telescope costs more than 1.25-inch eyepieces. And the reason is obvious. 2” eyepieces have more lenses than 1.25 eyepieces.
They are bigger, heavier, and even sturdier than 1.25” ones. Some 2” eyepieces even have more coatings than 1.25 eyepieces. Thus they have a better reflection of the image.
Comparatively 1.25” eyepieces are more budget-friendly. But the price range for 1.25 eyepieces can also be high. It generally depends on the eyepiece quality and brand.
Winner: 1.25”
Final Verdict: 2 Vs 1.25 Eyepieces
It’s hard to pick just one between Both 2” and 1.25” eyepieces. And truthfully you don’t even need to. Because as a stargazer you’d need both 1.25” and 2” eyepieces.
So no need to have a nerve-wracking battle between both eyepieces. The more eyepieces you have in your collection the better. But you should be careful about their quality.
After all, not all manufacturers offer good quality eyepieces. Also, evaluate all the mentioned aspects if you’re to buy either of the two sizes.
2” eyepieces are considered premium due to their FOV. So, if you need a big view of the night sky, 2” would be better. If you need wider FOV with high magnification buy 2” eyepieces with short focal lengths.
For high to mid-tier magnification go for 1.25” eyepieces. They would be especially good for observing objects like the moon’s cluster.
Hopefully, our provided details will be of guidance to you.
FAQs
Although we’ve tried to include every detail, it’s impossible to explain all at once. So, we’ve added some of the most commonly asked questions and their answers.
Which focal length eyepiece is best for watching planets?
A setup specifically for having the best planetary view, a 900mm telescope would be better. To get the highest magnification, use an eyepiece with a focal length of 4.5mm. With this short focal length, you’d achieve the best magnification. Also, the images would be bright and easily noticeable.
Are 1.25” and 2” telescope eyepieces interchangeable?
In most cases, they are interchangeable. 1.25 inches is the most common eyepiece size for telescopes. They are adaptable to almost all types of telescopes. The same can’t be said about 2” eyepieces. Although many telescopes are adaptable with 2” eyepieces some need an extra adapter to fit.
What eyepiece will be best for watching the moon?
To get the best view of the moon you’d need an eyepiece with mid-range magnification. Pick an eyepiece with a focal length ranging between 13-14mm. It’ll give about 150X magnification. Among the eyepieces with lower magnification, 25mm-30mm would be better. It’ll provide at least 75X magnification.
What eyepiece is the best for watching galaxies?
Plossl eyepieces are the best when it comes to observing galaxies. Their design is more fitting for watching bigger cosmic objects like clusters, nebulae. For watching galaxies, getting 15mm or 25mm Plossl would be the best.
Why are refractors better than reflectors for watching planets?
Compared to reflectors, refractors have a smaller aperture. It makes the refractor more advantageous when it comes to planetary observing. It also provides bright and detailed images of planetary surfaces.
Final Words
It’s time to wrap up our discussion regarding 2 vs 1.25 eyepieces. Hopefully, we succeeded in providing the answers you’ve been looking for.
Whether it’s a 2” or 1.25” eyepiece, know that it won’t be a waste. What matters most is its optical quality of it. So we hope our recommendation will be of help to you.
That’s it for today. Happy stargazing!
