Telescope eyepiece upgrade order for a beginner
We may earn a commission if you buy through these links — at no cost to you.
SVBONY 6 mm, 68° eyepiece
6 mm focal length, 68° apparent field — step 1 in the upgrade order
Magnification is your telescope's focal length divided by 6, so run the arithmetic in the section above before you order: about 108x on a 650 mm scope, and it climbs fast on a longer tube. The rule this order is built on is that one good eyepiece beats three mediocre ones.
Check the current price on Amazon ›The eyepieces bundled with a beginner telescope are the part the manufacturer saved money on, and upgrading them improves the view more than any other spend, including a bigger telescope. But the upgrade order matters, because two of the four obvious purchases are wasted.
The upgrade order at a glance:
| Order | Upgrade | Role | Why it comes here | Link |
|---|---|---|---|---|
| 1 | Quality mid-power eyepiece (around 60x to 100x) | The workhorse: planets on average nights, the Moon in detail, brighter deep-sky objects | One good eyepiece here beats three mediocre ones | 68-degree eyepiece |
| 2 | Better low-power, wide-field eyepiece | Your finder and framing tool; shows star clusters as clusters | The wide field makes the object hard to lose; the one to hand a child | Wide field 32mm |
| 3 | A 2x Barlow | Doubles the magnification of every eyepiece you own | Two eyepieces plus a Barlow gives four magnifications, cheaper than a third eyepiece | 2x Barlow |
| 4 | Filters | A Moon filter genuinely helps; a broadband light-pollution filter helps some suburban targets | Only now, after the glass is sorted; coloured planetary sets are the classic beginner waste | Moon filter |
First, the arithmetic you need
Magnification = telescope focal length ÷ eyepiece focal length. A 1000mm telescope with a 25mm eyepiece gives 40x. Shorter eyepiece, more magnification, dimmer and shakier image.
Maximum useful magnification is roughly 2x the aperture in millimetres, and only on a night with steady air. A 130mm telescope tops out near 260x in theory and near 150x on most real nights. Every “675x!” claim on a box is measuring nothing.
Exit pupil = eyepiece focal length ÷ focal ratio. Above about 6 to 7mm you are throwing light past your iris; below about 0.5mm the image is dim mush. That bounds your useful eyepiece range at both ends, and it is why the recommendations below are what they are.
The upgrade order
1. A quality mid-power eyepiece, around 60x to 100x on your scope
This is the workhorse: planets on average nights, the Moon in detail, brighter deep-sky objects. Buying one good eyepiece here beats buying three mediocre ones. Look for a 60-degree-plus apparent field and long eye relief.
68 degree wide angle telescope eyepiece
2. A better low-power, wide-field eyepiece
Your finder, your framing tool, and the one that shows star clusters as clusters. This is the eyepiece that gets the “oh” out of visitors, and it is the one to hand to a child, because the wide field makes the object hard to lose.
wide field telescope eyepiece 32mm
3. A Barlow, instead of a third eyepiece
A 2x Barlow doubles the magnification of every eyepiece you own, so two eyepieces plus a Barlow gives you four magnifications. Cheaper than a third eyepiece and more flexible. Buy an achromatic or apochromatic one; the plastic Barlow in a bundle is worse than not using one.
4. Only now, filters
A Moon filter genuinely helps, because a full Moon through a decent scope is uncomfortably bright. A broadband light-pollution filter helps some targets from a suburb and does nothing for galaxies. Coloured planetary filter sets are the classic beginner waste.
What not to buy
- The highest-magnification eyepiece available. Above your scope’s useful limit you get a bigger, dimmer, blurrier image of the same thing.
- A zoom eyepiece as your first upgrade. Convenient, and optically compromised at both ends of its range. A reasonable third purchase, a poor first one.
- A “kit” of eight eyepieces and filters in a case. The case is the best part.
Frequently asked questions
What is the best eyepiece to buy first for a beginner telescope?
A quality mid-power eyepiece giving 60x to 100x on your scope. This is the workhorse: planets on average nights, the Moon in detail, brighter deep-sky objects. Buying one good eyepiece here beats buying three mediocre ones.
Should I buy a zoom eyepiece as my first upgrade?
No. A zoom eyepiece is convenient but optically compromised at both ends of its range. It is a reasonable third purchase, a poor first one. Start with a quality fixed focal length.
What is a Barlow lens and do I need one?
A 2x Barlow doubles the magnification of every eyepiece you own, so two eyepieces plus a Barlow gives you four magnifications. It is cheaper than a third eyepiece and more flexible. Buy an achromatic or apochromatic one.
Are telescope eyepiece kits worth it?
Usually no. The case is the best part. Eight mediocre eyepieces you rarely use is worse than three quality ones you reach for. The bundled eyepieces in beginner scopes are the part the manufacturer saved money on.
What is the maximum magnification for my telescope?
Roughly 2x the aperture in millimetres, and only on a night with steady air. A 130mm telescope tops out near 260x in theory and near 150x on most real nights. Every 675x claim on a box is measuring nothing.
The upgrade that is not an eyepiece
If the image shakes when you touch the focuser, the mount is your limit, not the optics. Fix that before buying any glass. And if the telescope lives in a cupboard because setup takes twenty minutes, the honest upgrade is binoculars, which our stargazing binocular guide covers.