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If you’ve started shopping for a launch monitor, you’ve probably noticed they fall into two camps: radar units that sit behind you, and camera (photometric) units that sit beside the ball or hang from the ceiling. Some newer models combine both.
The difference isn’t just technical trivia. It decides how big your room needs to be, how reliable your spin numbers will be indoors, whether you need special balls, and whether the unit is any good at the driving range.
We haven’t lab-tested these units ourselves. This explainer is built from manufacturer documentation, retailer setup guides and independent comparisons, linked at the bottom so you can dig deeper.
The 30-second version
- Radar (Doppler) units watch the ball fly. They tend to shine outdoors, where they can track a lot of the flight, but they need more room depth indoors.
- Camera (photometric) units take high-speed images of the ball (and sometimes the club) at impact. They don’t need to see ball flight, so they suit smaller indoor rooms.
- For a typical home simulator room, many guides recommend camera-based units, especially if your room is under about 16 feet deep.
How Doppler radar launch monitors work
Doppler radar works by sending out a microwave signal and measuring how it bounces back off a moving object. As the ball moves away, the frequency of the returning signal changes, and the unit uses that change to calculate speed and direction. By tracking the ball over time, it can work out launch angle, spin and the shape of the flight.
Radar launch monitors are usually placed on the ground several feet behind the golfer, looking down the target line. Shop Indoor Golf’s placement guide, for example, lists the Garmin Approach R10 at about 6 to 8 feet behind the tee and the FlightScope Mevo+ at about 8 feet.
Why radar needs space indoors
Because radar measures the ball as it travels, it needs to see enough of the flight. Outdoors, the top radar systems can follow a ball a very long way. Indoors, the ball might only travel 8 to 12 feet before hitting the screen, so the unit has less data and must estimate more of the trajectory.
That’s why radar units come with larger recommended room depths. Retailer guidance for several popular radar units suggests total room depths of around 18 to 19 feet, and Trackman’s guidance for Trackman 4 indoors starts around 17 feet of total length with more preferred. Below roughly 16 feet, several independent guides say spin readings become less reliable.
Metallic dots for spin
Some radar units read spin much better indoors when you use balls with a small metallic sticker or dot, or purpose-made balls. Trackman and several others note this. It’s a small ongoing cost and hassle, so check whether the unit you’re considering recommends it.
Radar strengths
- Excellent outdoors, where it can track real ball flight, including the effect of wind.
- Many affordable radar units exist, which makes them popular first launch monitors.
- Can double as a range or on-course practice tool.
Radar weaknesses
- Needs a deep room indoors.
- Spin and some club data may be estimated rather than directly measured, particularly on budget units.
- Placement behind the golfer can be awkward to share between left- and right-handed players.
How camera (photometric) launch monitors work
Photometric units use high-speed cameras to photograph the ball in the moments right after impact. By comparing images, the system measures ball speed, launch direction and angle, and spin directly. Higher-end units also capture the club head to report data like club path and face angle. Foresight’s GCQuad, for instance, uses four high-speed cameras around the impact zone.
Because everything happens in the first fraction of a second, the unit doesn’t need to see ball flight. The software then models the rest of the shot.
Placement options
- Beside the ball: e.g. SkyTrak models, Foresight GC3 and GCQuad, Garmin Approach R50. These sit on the floor facing the golfer, usually a foot or two away from the ball.
- Overhead: e.g. Uneekor EYE XO2, Foresight GCHawk, Trackman iO. These mount on the ceiling above the hitting area, so they work for left- and right-handed players without moving anything.
Camera strengths
- Works in shallower rooms, often around 10 to 13 feet deep for side-mounted units (check the specific model).
- Measures spin directly at impact, which many guides consider a big advantage indoors.
- Generally less affected by the short ball flight of an indoor setup.
Camera weaknesses
- Outdoors, it can’t track actual ball flight, so wind and real-world roll are modelled rather than observed.
- Beside-the-ball units usually need repositioning for left-handed golfers.
- Some are sensitive to lighting conditions and need to be level with the hitting surface.
- The high-end photometric units are typically expensive.
Hybrid systems
The lines are blurring. Trackman 4, for example, combines dual radar with a camera, and several newer consumer units pair radar with cameras to improve accuracy. If a unit claims to be “hybrid,” look at what each sensor actually measures and what the manufacturer says about indoor use and room size.
Lighting, balls and other indoor gotchas
Beyond room depth, a few practical details trip people up with both technologies:
- Lighting: camera units rely on clear images of the ball. Very bright sunlight through a garage door, or flickering lights, can affect some units. Many come with their own infrared or built-in illumination, but read the manual’s lighting section before you buy.
- Ball choice: some units read spin best with specific balls or markings. Radar units may recommend metallic dots indoors; some camera units recommend clean, unmarked balls or particular brands. Using scuffed range balls can change readings.
- Alignment: every launch monitor needs to be aimed correctly at your target. A unit pointed a few degrees off will report every shot as a push or pull. Most apps include an alignment routine, and it’s worth redoing whenever the unit is moved.
- Software and subscriptions: the hardware is only half of the experience. Course play, practice games and detailed data often depend on the app or simulator software, and some features need an ongoing subscription. Check what’s included, what costs extra, and whether third-party simulator software is supported.
- Power and connectivity: some units run on battery, others need mains power or a cabled connection to a PC. If your simulator PC sits across the room, plan the cable runs and Wi-Fi early.
None of these is a reason to avoid either technology, but they’re the kinds of details that separate a setup you love from one you constantly fiddle with.
Side-by-side comparison
| Radar (Doppler) | Camera (Photometric) | |
|---|---|---|
| Where it sits | Behind the golfer | Beside the ball or overhead |
| What it measures | Ball in flight | Ball (and often club) at impact |
| Typical indoor room depth | About 16 to 20+ ft | About 10 to 15 ft |
| Outdoor use | Generally strong | Works, but flight is modelled |
| Indoor spin | May need metallic dots or be estimated | Measured directly |
| Left/right-handed sharing | Usually fine | Side units need moving; overhead units don’t |
Which should you choose?
Instead of asking “which is best,” ask these questions:
- Where will you mostly use it? Mostly indoors in a normal room: camera-based is usually the safer bet. Mostly outdoors at the range: radar makes a lot of sense.
- How deep is your room? Under about 16 feet: shortlist camera units. 18 feet or more: radar is a real option too. See our room size guide.
- How much do you care about club data? If you want detailed club path and face data, look carefully at what each unit actually measures versus estimates.
- Who else will use it? Mixed left- and right-handed households benefit from overhead units or radar.
- What’s the total cost? Many launch monitors require a paid subscription to unlock features or simulator software. Factor that in, not just the hardware price.
Common myths
“Radar is always less accurate.” Not really. Top-tier radar systems are used by tour pros and fitters. The issue is indoor space and how much a given unit estimates versus measures.
“Cameras work in any room.” They need less depth, but you still need enough ceiling height and width to swing safely, plus suitable lighting.
“More data equals better practice.” Only if you understand and use it. For many golfers, reliable carry distance, ball speed and spin is plenty.
Bottom line
Radar watches the ball fly; cameras photograph the moment of impact. For most home simulator rooms, that makes camera-based units the easier fit, while radar units shine if you have a long garage or practice outdoors a lot. Measure your room, decide where you’ll use it most, and then compare models within the right technology.
Sources
- Shop Indoor Golf, Launch monitor placement and room requirements
- My Golf Simulator, Trackman space requirements
- PlayBetter, GCQuad home space requirements
- Northcourse, Photometric vs Doppler radar