Radar vs Photometric Launch Monitors: How Each Works and Which Suits Your Room

Every home launch monitor answers the same question (how fast, how high, how much spin, which way) in one of two ways. It either bounces radar off the ball as it flies, or it photographs the ball with high-speed cameras as it leaves the club. A growing group, the hybrids, does both. Which approach a unit uses decides where it sits in your room, how deep that room has to be, whether you need special balls or stickers, and whether left-handers have to move it.

This explainer covers how each technology works, what it means for an indoor simulator, and which models fall into each camp. We haven’t tested these units ourselves; findings are attributed to the outlets that ran them, and prices are Amazon’s on November 12, 2026, which change often.

How Doppler radar launch monitors work

A radar launch monitor sends out a microwave signal and measures how the reflection shifts as the ball (and club) moves, the Doppler effect. It sits on the floor behind the golfer, looking down the target line, and reads the ball for as long as it can see it.

That has two consequences. First, the unit has to be well back from the ball and the ball needs room to fly before it hits the screen or net. Garmin’s manual puts the Garmin R10 6–8 ft behind the tee with at least 8 ft from the tee to the net indoors. The Full Swing KIT wants 8–10 ft behind the ball and 8–10 ft of flight. Second, a short indoor flight gives the radar less ball to read, and spin is where that shows most.

Radar-only examples on our list:

• Voice Caddie SC4 PRO, about $499.99: 5 ft behind the ball and 9–10 ft to the net. Voice Caddie doesn’t say whether spin is measured or calculated.
• Garmin Approach R10, about $499.99: spin is calculated from radar data, not directly measured.
• Full Swing KIT, about $3,995.95: 24 GHz dual-mode radar with 16 metrics including face angle.

How photometric (camera) launch monitors work

A photometric unit uses high-speed cameras, often with infrared light, to take a burst of images of the ball (and on many units, the club) in the first few inches after impact. Speed, launch, direction and spin come from those images. Because the measurement happens at impact, the ball only needs enough flight to reach the screen safely.

These units sit beside the ball, facing it, usually raised to the height of the hitting surface. Examples:

• Uneekor EYE MINI CORE (about $999) and EYE MINI LITE (about $1,699): two infrared cameras that read the dimples, with no marked balls. Windows PC, Ethernet and mains power; indoor only.
• Bushnell Launch Pro (about $1,995), Launch Pro i (about $1,354) and Foresight GC3 (about $3,799–3,999): the same three-camera hardware. Plugged In Golf found the Launch Pro’s ball speed typically an exact match with a GCQuad and spin within tens of rpm.
• Garmin Approach R50, about $4,999.99: three high-speed cameras about 1.5 ft to the side of the tee, with the simulator running on its own 10-inch screen.

Club data on camera units usually needs club stickers. The Launch Pro, GC3, R50 and EYE MINI LITE all use them; SkyTrak’s units read face and path without stickers.

Hybrids: radar plus cameras

Hybrids combine a radar with one or more cameras. Where they sit depends on the design:

• Behind the ball: the Rapsodo MLM2PRO (about $549.98) and MLM2XPRO (about $899.99) pair Doppler radar with cameras, 7.5 ft behind the ball. The FlightScope Mevo Gen2 (about $1,149) uses 3D Doppler radar with image processing, which FlightScope calls Fusion Tracking, 7–9 ft behind.
• Beside the ball: the SkyTrak+ (about $995) and ST MAX (about $1,695) sit next to the ball and get spin from camera images. SkyTrak describes the ST MAX as dual Doppler radar plus photometric cameras, and Breaking Eighty says its hardware is identical to the SkyTrak+.

Because the hybrids that sit behind the ball still track a radar signal down the line, they need about as much depth as radar-only units.

Why indoor radar spin needs help

Spin is the hardest number for radar indoors, and makers handle it differently:

• Calculated: the Garmin R10 calculates spin from radar data. Plugged In Golf found it often in line with a pro unit outdoors, less often indoors, with spin high on wedges and mishits.
• Metallic dots or RCT balls: FlightScope’s FAQ asks Mevo Gen2 owners to use aluminum dots (100 in the box) or Titleist RCT balls for accurate indoor spin. Full Swing recommends RCT balls for the KIT indoors. RCT balls have a radar-readable layer; a 12-pack of Pro V1 RCT is about $74.99.
• Camera-measured with special balls: Rapsodo’s hybrids measure spin with the camera, but only with Rapsodo RPT balls, an active membership and the “Net” environment selected. RCT balls are not a substitute for RPT on Rapsodo.

Camera units measure spin directly from the images, with no special balls. SkyTrak suggests turning the ball’s logo toward the lens for the best reads, and Garmin asks the same of R50 owners, especially with matte balls.

None of this makes radar unusable indoors. Breaking Eighty found the Mevo Gen2 within 1–2 yards and 200 rpm of a Trackman on about 7 in 10 indoor shots, with some drives off by 5–7 yards.

Room depth: the biggest practical difference

Here is the minimum room depth each unit needs, using the makers’ own setup figures (our room size guide explains how we add them up).

Two things stand out. Side units aren’t automatically the short-room answer: Uneekor asks for a 15 ft deep room, the same as a Mevo Gen2’s minimum. And depth isn’t only about the monitor. Carl’s Place puts a general minimum at 15 ft and an ideal room at 18–20 ft once you allow for space behind the screen and a full swing. If you’re tight on depth, our small-room picks go through the options.

Check your own numbers with the room size checker, which filters monitors by depth, ceiling, width and placement.

Left-handers and mixed households

Side-of-ball units face the ball from one side, so a left-handed golfer stands where the unit sits. Uneekor’s help center says left-handers must move the EYE MINI to the opposite side of the hitting area. SkyTrak’s ST MAX guide mentions a “left handed mode” but SkyTrak doesn’t publish how to reposition it. Either way, budget the width: SkyTrak suggests 12 ft plus 1–2 ft for mixed-handed play, and Carl’s Place says 14 ft or more for a centered tee.

Behind-the-ball units look straight down the target line, so the unit itself doesn’t have a side to switch; you still need the swing room on whichever side the golfer stands. A dual-stance mat such as the SIGPRO Softy 4 × 10 ft helps households with both.

To filter by handedness, set hand=both in the room size checker.

Outdoor use

Radar and the behind-the-ball hybrids are built for the range as well as the garage: the R10, SC4 PRO, MLM2PRO, MLM2XPRO, Mevo Gen2 and KIT all run on batteries and work outdoors. Outdoor results vary by unit. Plugged In Golf found the MLM2XPRO read short clubs long outdoors, and Carl’s Place, a KIT retailer, measured an average outdoor driver carry error of 6.25 yards in its KIT test.

Camera units split. The SkyTrak+, ST MAX, Launch Pro, GC3 and R50 work outdoors; Today’s Golfer saw the R50 miss about 1 in 100 shots outside. The Uneekor EYE MINIs and Launch Pro i are indoor only and need mains power. For battery life, weight and plan costs by unit, see our ranking of the best launch monitor for outdoor driving range practice.

Which technology should you choose?

• Long room (16 ft or more), want the range too: a behind-the-ball radar or hybrid. The Mevo Gen2 has no subscription; the MLM2PRO is the budget choice with measured spin.
• Short room (12–14 ft): a side-of-ball unit. The SkyTrak+ is the cheapest, the Launch Pro the most accurate by reviewers’ tests.
• Dedicated indoor room with a gaming PC: a Uneekor EYE MINI, which reads plain balls and connects to GSPro.
• Left- and right-handed golfers sharing: a behind-the-ball unit avoids moving hardware, or plan width for a side unit.

Technology is only one part of the decision. Software and yearly fees often cost more than the hardware gap, so compare plans in our software guide, and see every unit side by side in the comparison chart. The launch monitor matcher narrows the list by your room and budget, and our best launch monitors for home ranking explains our picks.