Telescope Comparison
Celestron Advanced VX 8 SCT vs Celestron RASA 8"
The Celestron Advanced VX 8 SCT is a complete setup. The Celestron RASA 8" needs a mount before it's usable.
First light
Celestron · 203mm · £1,699
The automated deep-sky platform
- 203mm schmidt-cassegrain on a computerised mount with motorised tracking
- Good for: Moon, planets, bright nebulae, star clusters, and deep-sky objects
- GoTo system finds any object in its database after initial star alignment — no star atlas needed
- Tracking motors keep objects centred as Earth rotates — useful above 100×, essential for photography
- 22kg total — requires a fixed garden spot or car transport
Celestron · 203mm · £1,799
The custom-rig optical tube
- 203mm schmidt-cassegrain — optical tube only, no mount included
- 406mm focal length at f/2
- Requires a compatible mount before you can observe anything
- Best for: observers who already own a suitable mount or are building a specific imaging rig
- Not a complete purchase — budget at least £100–300 extra for a mount before observing
The full picture
The numbers that separate these two scopes — and what they mean at the eyepiece.
Aperture
Equal light-gathering. Aperture won't settle this comparison — the mount, focal ratio, and observing experience are what differ.
Focal length
Celestron Advanced VX 8 SCT's longer focal length reaches higher magnification with the same eyepiece — better reach for planetary detail. Celestron RASA 8"'s shorter focal length gives a wider true field — better for large open clusters and extended nebulae.
Focal ratio
Celestron RASA 8"'s faster f/2 delivers wider fields with any eyepiece — better for open clusters and large nebulae. Celestron Advanced VX 8 SCT's f/10 provides more magnification per eyepiece — better for fine planetary detail.
Mount type
Celestron RASA 8" has no mount — add a compatible mount before you can observe. Celestron Advanced VX 8 SCT is a complete ready-to-use system.
Weight (OTA)
Similar optical tube weight. Any portability difference between these setups comes from the mount, not the tube itself.
Optical design
Both Schmidt-Cassegrain designs — versatile, compact, good for planets and deep-sky. Differences come from aperture and mount.
At the eyepiece
Both scopes · same aperture
Both scopes share essentially the same aperture — views through each will be very similar on all standard targets. The differences show up in setup, mount type, and focal ratio, not in fundamental light-gathering.
The real tradeoff
Both scopes are capable. The question is which one fits the way you actually observe.
The Celestron Advanced VX 8 SCT is a complete package — everything arrives in one box and you can observe the same day. The Celestron RASA 8" is a bare optical tube that needs a separate compatible mount before you can point it at anything, adding significant cost and complexity. Unless you already own a suitable mount, the Celestron Advanced VX 8 SCT is the practical choice.
The dark side
Every scope has a personality. Here’s where each one gets difficult.
Celestron
Celestron Advanced VX 8 SCT
Alignment required every session
GoTo star alignment cannot be skipped — the mount needs to know where it is pointing before it can find objects. This adds several minutes to the start of every session, every time.
Not a spontaneous telescope
At 22kg total, this goes out when you plan to go out — not for a quick look on a clear evening.
Celestron
Celestron RASA 8"
No mount included
You cannot observe until you buy a separate compatible mount — add at least £100–300 before you have a working telescope.
Nothing to look through on day one
Until a mount arrives, the optical tube is a piece of glass you cannot point at the sky.
Which is right for you?
Two different buyers. Two different right answers.
The automated deep-sky platform
Celestron · Celestron Advanced VX 8 SCT
You’ll love this if…
- You want to navigate straight to targets without a star atlas — align once and the scope slews to any object in its database on demand
- You observe from a light-polluted garden where star-hopping to faint deep-sky objects would take most of a clear night
- Astrophotography is where you're headed — the tracking equatorial mount is the essential first component of any imaging setup
This will frustrate you if…
- You find the star alignment required at the start of every session frustrating — GoTo alignment cannot be skipped, and several minutes on a cold night before you can observe is the reality
- You want to take it out for spontaneous sessions — at this weight, getting it in and out of a car on your own requires planning and ideally a second pair of hands
The custom-rig optical tube
Celestron · Celestron RASA 8"
You’ll love this if…
- You already own a compatible equatorial or alt-az mount — this is the optical tube you've specifically chosen to put on it
- You're building an imaging rig piece by piece and know exactly what you need at the end of a focuser
- Choosing an optical tube independently of the mount gives you more flexibility over your overall system
This will frustrate you if…
- You buy it without fully accounting for the mount — add at least £100–300 to the purchase price before you have a working telescope
- You expected a complete package and didn't realise this is a bare optical tube that cannot be used without a separate mount
Our verdict
This comparison has a catch: the Celestron RASA 8" is a bare optical tube. You cannot use it without a separate mount — which adds meaningful cost and complexity. The Celestron Advanced VX 8 SCT is a complete, ready-to-observe package.
For most buyers, the Celestron Advanced VX 8 SCT is the right choice — you can observe the same night it arrives. The Celestron RASA 8" makes sense if you already own a compatible mount, or are deliberately building a specific imaging setup piece by piece. If I had to choose for a first telescope: the Celestron Advanced VX 8 SCT, without hesitation.
Celestron Advanced VX 8 SCT
View Celestron Advanced VX 8 SCT →Celestron RASA 8"
View Celestron RASA 8" →Deep field: Full specifications
Every data point, for those who want to go further.
Full specifications
Fields highlighted in blue or amber indicate the better value for that spec. Data is manufacturer-stated and may vary.
How much can it see?
| Spec | Celestron Advanced VX 8 SCT | Celestron RASA 8" |
|---|---|---|
Aperture The most important spec — bigger = more light = better views | 203mm | 203mm |
Focal Length Longer = more magnification potential | 2032mm | 406mm |
Focal Ratio Lower f-number = wider field of view; higher = more magnification per eyepiece | f/10 | f/2 |
Optical Design The type of optics — each design has different strengths | Schmidt-Cassegrain | Schmidt-Cassegrain |
Coatings Better coatings = more light transmission through the optics | StarBright XLT multi-layer coatings | Fully multi-coated Rowe-Ackermann Schmidt optics |
How do you point it?
| Spec | Celestron Advanced VX 8 SCT | Celestron RASA 8" |
|---|---|---|
Mount Type The mechanical system that holds and moves the telescope | GoTo (Computerised) | None (OTA only) |
GoToⓘ Computer-controlled pointing — finds any of thousands of objects automatically | ||
Trackingⓘ Motor keeps objects centred as the Earth rotates — essential for astrophotography |
The focuser
| Spec | Celestron Advanced VX 8 SCT | Celestron RASA 8" |
|---|---|---|
Focuser Size 2" accepts wider eyepieces and gives better low-power views | 2" | — |
Focuser Type Rack-and-pinion is standard; Crayford and dual-speed are smoother | SCT rear-cell focuser with reducer thread | Camera threads directly to rear cell (T-thread) |
Size & weight
| Spec | Celestron Advanced VX 8 SCT | Celestron RASA 8" |
|---|---|---|
OTA Weightⓘ Optical tube only — useful for comparing mount load capacity | 5.4kg | 5.9kg |
Total Weight Full setup including mount — this is what you lug to the car | 22kg | — |
Tube Length | 432mm | 368mm |
Tube Material | Aluminium | Aluminium |
What's in the box?
| Spec | Celestron Advanced VX 8 SCT | Celestron RASA 8" |
|---|---|---|
Eyepieces Included eyepieces — more is better, but quality matters more than quantity | 40mm eyepiece | — |
Finder Scope Helps you locate areas of the sky before switching to the main eyepiece | 8x50 right-angle finder scope | — |
Diagonalⓘ Tilts the eyepiece 90° for comfortable viewing — useful on refractors |
Smart features
| Spec | Celestron Advanced VX 8 SCT | Celestron RASA 8" |
|---|---|---|
Built-in Camera Records and stacks images automatically — no separate camera needed | ||
App Controlled | ||
WiFi | ||
Battery Included |
Blue highlight: Celestron Advanced VX 8 SCT advantage · Amber highlight: Celestron RASA 8" advantage · Greyed cells: equal or subjective.