Handheld vs turntable 3D scanning: which one suits what

There are two ways to get an object into a mesh: move the object past a fixed sensor, or move the sensor around the object. That one distinction drives most of what a 3D scanner is good and bad at, and it matters more than the brand or the headline accuracy figure.

Most of what is sold on Amazon UK now is handheld — the Creality CR-Scan Ferret, Otter and Raptor families, the Revopoint POP and Mini series, the 3DMakerpro Seal, Mole and Moose, the EINSTAR range. Dedicated desktop turntable scanners such as the Matter and Form MFS1V2 and the Shining 3D EinScan SE are a much smaller part of the market than they were, and several handheld scanners now ship with a small turntable so you can work both ways.

Desktop turntable scanning

The object sits on a motorised platter, the scanner stays put, and the software knows exactly how far the platter has rotated between frames. That known rotation is the whole advantage: alignment comes from the mechanism rather than from guessing, so error does not accumulate the way it does when a hand-held sensor has to work out where it has moved to.

What it is good at:

• Small to medium rigid objects — roughly fist-sized up to the platter’s stated limit.
• Repeatability. Set it up once and every scan runs the same way.
• Featureless shapes. A smooth cylinder defeats feature-based alignment but is no trouble at all on a turntable.
• Working unattended. Press start, let it run.

What it cannot do: anything that will not fit on the platter, anything too heavy for it, anything fixed in place, and anything alive. Turntable scans also need at least two passes at different angles to capture top surfaces and undercuts, because the platter view misses whatever faces straight up or straight down.

Handheld scanning

You walk the sensor around the object while software stitches the frames together in real time. It is far more flexible and considerably less forgiving.

Good at:

• Large objects — car panels, furniture, machinery, anything that could never sit on a turntable.
• Objects you cannot move, including parts still installed on a machine.
• People. Faces, hands, torsos, pets — the scanners aimed at this use high frame rates and near-infrared light for exactly this reason.
• Awkward access — you can reach into a recess that a fixed sensor would never see.

Less good at: small objects, oddly enough. Below about 20–30 mm many handheld scanners cannot get close enough to focus, which is why the small-object models (the Revopoint Mini 2 and the 3DMakerpro Seal series, among others) are sold as a separate line rather than as the same scanner with a different setting. Check the stated minimum object size before buying for miniatures.

Handheld scanning is also a learned skill. Keeping the working distance steady, moving at the right speed and not breaking tracking takes practice, and the first few scans of anyone’s life are poor. That is not a fault in the hardware.

What marker dots are for

Marker dots are small reflective stickers you place on or around the object so the scanner has unambiguous reference points to align frames against. They look crude and they work extremely well.

You need them when the object is geometrically featureless — a flat panel, a smooth curve, a plain cylinder — because feature-based alignment has nothing to lock onto and the scan drifts or splits into two misaligned halves. You do not need them on a part with plenty of distinct shape, and they are a nuisance there, since every dot leaves a flat patch in the mesh that has to be repaired afterwards.

Marker-free operation is advertised heavily (the EINSTAR Rockit and Creality Raptor families both make a point of it) and it does work on suitable objects. Treat it as “markers needed less often”, not “markers never needed”. Keep a sheet in the drawer alongside the matting spray.

The three light sources, and when each wins

• Structured light. A pattern is projected and the distortion read. The cheapest approach, good on small and medium matte objects, and the most affected by bright ambient light — which is why these scanners are indoor tools. Most sub-£400 scanners work this way.
• Blue laser (line or multi-line). Narrowband laser lines cut through ambient light and cope far better with dark and shiny surfaces. Listings advertise the line count — 7, 17, 22 blue lasers — because more lines means more surface covered per pass and faster scanning. This is the technology on the mid and upper range, and the reason those scanners work outdoors.
• Near-infrared (NIR). Invisible and comfortable to look at, so it is the usual choice for scanning faces and bodies, and it handles some darker surfaces better than visible structured light. Generally lower resolution than blue laser on rigid parts.

Several current scanners carry two of these and switch between them — blue laser for rigid parts, infrared for people. If you want to do both, that dual capability is the specification to look for rather than buying on accuracy alone.

Choosing between them

• Mostly small rigid objects, on a desk, repeatedly — a turntable, or a handheld scanner bundled with one.
• Mixed bag of medium parts around the house or workshop — handheld, with a turntable in the box for the small ones. This suits most people.
• Large parts, vehicles, installed machinery — handheld with blue laser, and pay attention to the volumetric accuracy figure rather than the headline one.
• People and pets — handheld with infrared and a high frame rate.
• Miniatures under about 30 mm — a dedicated small-object scanner, and check the minimum scan size in the specification.

What the numbers in those specifications really mean is covered in what 3D scanner accuracy figures actually mean; what each budget buys is in 3D scanner price bands in the UK. If the plan is to print what you scan, read what the workflow actually needs first — and if you have not settled on a printer yet, see FDM vs resin. Live prices for everything mentioned here are on the 3D scanners page.