Telescope Mount Types Explained: Alt-Az vs EQ vs GoTo Mounts
AllenDingTelescope Mount Types Explained: Alt-Az vs EQ vs GoTo Mounts
The mount is the most important part of your telescope — more important than the optics. A great telescope on a bad mount delivers mediocre views. Here's what each mount type does, who it's best for, and how to choose the right one.
Why Mounts Matter More Than You Think
A telescope mount has two jobs:
- Stability: Hold the telescope steady without vibration
- Motion: Allow smooth movement to aim at targets and track them across the sky
A bad mount makes both jobs harder: vibrations blur the image every time you touch the scope, and jerky movements make it impossible to aim precisely. No amount of expensive optics fixes a wobbly mount.
Mount Type 1: Alt-Azimuth (Alt-Az)
The simplest type. Moves in two directions: up-down (altitude) and left-right (azimuth). Like a camera on a tripod.
- Intuitive to use ("push it where you want to look")
- No setup required beyond leveling the tripod
- Lightweight — good for portable setups
- Cheap
- Can be motorized (push-button tracking, though with field rotation)
- Earth's rotation means objects drift diagonally — you must adjust both axes constantly
- Not suitable for astrophotography (field rotation ruins long-exposure images)
- Manually tracking = physically moving scope every few seconds at high power
Best for: Visual observing, beginners, portable setups, planetary viewing, casual stargazing.
Not for: Long-exposure astrophotography.
Mount Type 2: Equatorial (EQ)
An equatorial mount has one axis (the Right Ascension or RA axis) aligned with Earth's rotational axis. This means rotating just one axis tracks celestial objects as Earth turns — no field rotation.
- Single-axis tracking (much easier than alt-az at high power)
- Motor drive possible: mount tracks automatically once aligned
- Essential for astrophotography (no field rotation with RA motor)
- Setting circles let you navigate by coordinates
- Requires polar alignment (pointing RA axis at Polaris) — takes 5-15 minutes
- Counterweight adds bulk and weight
- Counterintuitive to aim at objects (motion is not left/right, up/down)
- More expensive than alt-az for same stability
Best for: Serious visual observers, planetary observers, astrophotographers (with motor).
Not for: Casual stargazers who don't want to polar align every session.
Types of EQ Mounts
| Type | Best For | Payload Capacity | Cost |
|---|---|---|---|
| EQ2 | Small telescopes (70-90mm) | 3-5 lbs | $50-100 |
| EQ3/EQ3.2 | Medium scopes (90-130mm) | 8-12 lbs | $150-300 |
| EQ5 | Large scopes (130-200mm) | 12-15 lbs | $300-600 |
| HEQ5/EQ6 | Imaging rigs | 14-20 lbs | $600-1500 |
Mount Type 3: GoTo (Computerized)
GoTo mounts have a computer that knows where thousands of objects are located in the sky. After a brief alignment (pointing at 2-3 known stars), the mount will automatically move to any object you select.
- Finds objects automatically — no star hopping knowledge required
- Can point to objects you can't see yet (too faint to use as guides)
- Motor tracking included
- Great for astrophotography when combined with EQ base
- Motivating for beginners (actually see things on first night)
- More expensive ($300-2000+)
- Alignment required (~10-15 minutes)
- Needs power (batteries or AC)
- If alignment is off, GoTo accuracy is off — frustrating when it points to "wrong" spot
- Some argue it prevents learning the sky (but also gets people to actually use the telescope)
Best for: Impatient beginners, astrophotographers, serious deep-sky observers, urban observers.
GoTo Mount Subtypes
| Type | Base Mount | Best For |
|---|---|---|
| Alt-Az GoTo | Alt-azimuth | Visual observing, basic photos |
| EQ GoTo | Equatorial | Long-exposure astrophotography |
| Dobsonian GoTo | Dobsonian alt-az | Large aperture + convenience |
Mount Comparison Table
| Feature | Alt-Az | Equatorial | GoTo |
|---|---|---|---|
| Ease of use | ⭐⭐⭐⭐⭐ | ⭐⭐⭐ | ⭐⭐⭐⭐ |
| Setup time | 1-2 minutes | 5-15 minutes | 10-20 minutes |
| Visual observing | ⭐⭐⭐⭐ | ⭐⭐⭐⭐⭐ | ⭐⭐⭐⭐⭐ |
| Astrophotography | ⭐ (alt-az only) | ⭐⭐⭐⭐⭐ | ⭐⭐⭐-⭐⭐⭐⭐⭐ (depends on base) |
| Sky learning | ⭐⭐⭐⭐⭐ | ⭐⭐⭐⭐ | ⭐⭐ |
| Cost (for stability) | Lowest | Medium | Highest |
| Portability | ⭐⭐⭐⭐⭐ | ⭐⭐⭐ | ⭐⭐⭐ |
Special Case: Dobsonian Mount
A Dobsonian is a specific type of alt-azimuth mount — a rocker box that large reflectors sit in. It's extremely stable, simple, and cheap to build. The trade-off: no easy tracking for astrophotography.
Dobsonians are loved by amateur astronomers for their "maximum aperture per dollar" ratio. A 10-inch Dobsonian costs less than a 4-inch EQ mount with similar tracking capability.
The Dobsonian vs EQ Debate (Simplified)
| Goal | Recommendation |
|---|---|
| Maximum visual performance, no photography | Large Dobsonian (10"+) |
| Some photography, mostly visual | EQ mount, 90-130mm scope |
| Serious astrophotography | EQ5 or better GoTo mount + refractor/Cassegrain |
| Portable, casual use | Alt-az, 70-90mm |
Which Mount Should You Buy?
The honest answer depends on what you plan to do:
| If you want to... | Buy this mount type |
|---|---|
| Just look at the sky casually, no photography | Alt-azimuth (simplest) |
| Observe seriously + learn the sky | Equatorial (no motor) |
| Observe without learning star positions | Alt-az GoTo |
| Take long-exposure photos (nebulae, galaxies) | EQ5+ GoTo with motor |
| Take planet photos (short exposures) | Alt-az is acceptable |
When you're ready to upgrade — to an EQ mount with motor for serious observing, or a GoTo for convenience — you'll know exactly what you need. Start simple.
Polar Alignment (For Equatorial Mounts)
Polar alignment is the process of pointing the RA axis of your EQ mount at the celestial north pole (near Polaris). Without it, your mount won't track correctly.
Quick polar alignment (for visual use):
- Set latitude on the mount to your location's latitude (stamped on the side)
- Point the RA axis (polar axis) roughly north using a compass
- Adjust the altitude until Polaris is visible in the polar scope or finder
- Drift alignment (advanced): use a star drift test to fine-tune
For visual use, "rough" polar alignment is fine. For astrophotography with long exposures, precision alignment is required.
Quick Summary
Alt-Az: Point it where you want. Best for beginners and casual observers. Koolpte uses this.
Equatorial: Aligned to Earth's axis for smooth tracking. Best for serious observers and photographers.
GoTo: Computer-controlled pointing. Finds anything automatically. Best for convenience.
Dobsonian: Massive aperture, simple design. Best for dark-sky visual performance.
For most people: Start with an alt-az mount (like the one on all Koolpte telescopes), learn the sky, then upgrade to EQ or GoTo when you're ready for more.