Keep the supplied 25mm while learning the telescope. A useful eventual kit covers finding, general detail and higher-power nights. The best high-power focal length is different for the 6SE and 8SE.
Buying a large eyepiece case before your first clear night often creates more choices than useful views. Build around the magnifications you can actually use and the eye relief you find comfortable.
Calculate the magnification first
Magnification equals telescope focal length divided by eyepiece focal length. The 6SE's nominal focal length is 1500mm; the 8SE's is 2032mm. The following values are calculated, rounded to the nearest whole number, and assume no Barlow or reducer.
| Eyepiece | 6SE | 8SE | A useful role |
|---|---|---|---|
| 32mm | 47x | 64x | Lower-power finding and wider framing |
| 25mm supplied | 60x | 81x | Learn the scope before adding accessories |
| 18mm | 83x | 113x | Moderate-power comparison |
| 15mm | 100x | 135x | General lunar and planetary detail |
| 12mm | 125x | 169x | A measured step toward higher power |
| 10mm | 150x | 203x | Useful when the atmosphere permits |
| 9mm | 167x | 226x | More demanding, especially in the 8SE |
| 6mm | 250x | 339x | Too aggressive as a default first purchase |
Use the existing magnification calculator for other focal lengths. Focal length alone does not tell you the true field of view: apparent field and field-stop size also matter.
Two sensible three-piece targets
For a 6SE, a 32mm, 15mm and 9mm set gives about 47x, 100x and 167x. For an 8SE, 32mm, 18mm and 12mm gives about 64x, 113x and 169x. These are suggested spacing choices, not a requirement to buy three eyepieces at once.
Keep using the included 25mm while deciding. If you enjoy broad lunar views but want more detail, add the middle option first. If you routinely struggle to locate objects, investigate finder alignment and a useful wider view before buying high power.
A 32mm eyepiece and a wide-apparent-field 25mm can have similar true fields, depending on their designs. Compare specifications rather than assuming the longer focal length always shows much more sky. Our 25mm vs 32mm guide explains that choice.
Comfort can beat another specification
If you observe with glasses, check usable eye relief and whether you can see the full field without pressing against the eyepiece. Very short focal-length traditional designs can be uncomfortable. A comfortable view held steadily is more useful than a nominally impressive magnification you cannot maintain.
Consider weight too. Large accessories can complicate balance and clearance on a single-arm mount. The stock 1.25-inch diagonal makes a modest 1.25-inch kit the simplest first path; a 2-inch conversion is a separate decision, not an automatic upgrade.
Should you buy a Barlow or a kit?
A 2x Barlow roughly doubles magnification. With the supplied 25mm, that means about 120x in the 6SE or 163x in the 8SE. That can be useful if you already own a good compatible Barlow, but check overlap before paying for one plus a nearby fixed eyepiece.
For example, 25mm with a 2x Barlow and a separate 12mm offer very similar power. A kit containing many short eyepieces may spend much of your budget on magnifications that seeing rarely supports. Compare each included focal length in the table before counting the number of pieces as value.
A buying check that prevents disappointment
Confirm barrel size, focal length, eye relief, return policy and current availability. Do not buy a 9mm because it appears in a generic planet list without calculating what it does in your telescope.
Affiliate link: we may earn a commission at no extra cost to you. The Celestron X-Cel LX 9mm listing is one option to compare for a 6SE high-power step. At roughly 226x in an 8SE it is a more demanding choice, so the same recommendation does not transfer automatically. Check the selected focal-length variant before ordering.
If higher power makes everything soft, use our planetary troubleshooting sequence. Buying still more magnification will not solve turbulence, dew or poor focus.
Frequently asked questions
Is 300x a sensible everyday target?
No. Start lower and increase only while the view gains useful detail. The atmosphere and setup often determine the evening's practical limit.
Do I need to replace the supplied 25mm?
Not immediately. It is a useful reference that lets you discover which additional view you want.
Can this table predict exactly what I will see?
It predicts nominal magnification. Object altitude, seeing, thermal conditions, optical alignment and your eyes still affect the result.