A mini projector’s real brightness is its white light output measured under ISO/IEC 21118, the international spec-sheet standard for data projectors. In the compact class that figure runs from 300 to 1,000 lumens on the sheets of Epson, BenQ, XGIMI and Nebula.
A listing that promises 9,000 or 18,000 lumens is quoting something else. Epson has spent the last two years taking those sellers to court.
What an ISO 21118 lumen actually measures
ISO/IEC 21118:2020 is the ISO office-equipment standard that sets out what a data projector’s specification sheet must include. It fixes one test for white brightness: split the projected image into nine sections, meter the lux at the centre of each, average the nine, and multiply by the screen area.
The Japan Business Machine and Information System Industries Association, which drafts the matching JIS X 6911 standard, publishes that method in plain language.
ANSI, the US member body of ISO, has adopted ISO 21118, so a current “ANSI lumens” figure and an ISO figure from two brands come from the same test and are comparable.
One detail catches people out. The standard just says lumens. “ISO lumens” is marketing shorthand, and JBMIA lists it alongside “LED lumens”, “Laser lumens”, “Light Source lumens” and “Lux” as labels that say nothing about the method.
The marketing lumens Epson took to court
Epson America’s newsroom now reads like a corrections log. In July 2025 a US court entered a default judgment against Amazon seller Yowhick: its “9,000 lumen” projectors measured under 1 percent of that figure when tested to ISO 21118, and the company was barred from selling projectors online.
In December 2025 Yaber settled and cut the E1 from 18,000 lumens to 140. In February 2026 Nomvdic restated the L500 from 2,500 lumens to 500 and the P1000 from 2,300 to 1,300. Global Aiptek, which licenses the HP name, took the MP2000 Pro from 2,000 to 600.
In June 2026 Vizony revised the RD830 from “15,000 and/or 800” down to 370. Epson’s standing advice across those releases: treat “Lux”, “LED lumens” and “Lamp Brightness” as red flags, above all on marketplaces.
Four mini projectors with a standard on the sheet
All four name the method in a footnote. The drawbacks come from the same spec pages.
| Model | White brightness | Method cited | Resolution | The catch on the sheet |
|---|---|---|---|---|
| Epson EpiqVision Mini EF21 | 1,000 lumens | ISO 21118 (colour: IDMS 15.4) | 1080p | The 20,000-hour laser rating is the point where brightness has already dropped 50 percent |
| BenQ GV50 | 500 lumens | ANSI | 1080p | 2.1 kg, heavy for a portable; light source rated 20,000 hours normal or 30,000 in Eco |
| XGIMI MoGo 3 Pro | 450 lumens | ISO 21118 | 1080p | Rated only in Performance Mode, which XGIMI says shifts colour and raises fan speed; needs a 65 W USB-C supply |
| Nebula Capsule 3 Laser | 300 lumens | ANSI | 1080p | Dimmest of the four; the built-in battery is rated for one 2.5-hour movie |
XGIMI’s 450 figure is an average across mass-produced units “under ideal laboratory conditions in Performance Mode”, and XGIMI itself recommends other modes for regular viewing. Expect less light in the mode you will actually use, from every brand.
Epson’s colour brightness line is a separate measurement under IDMS 15.4, and Epson lists both figures at 1,000 lumens on the EF21. The other three publish white brightness only.
How to read a listing before you pay
Find the brightness footnote first. If it names ISO 21118 or ANSI, the number is comparable. If it says LED lumens, light-source lumens or lux, or has no footnote at all, you have nothing to compare and should move on.
Then match the number to the room. Epson rates the EF21 for day or night viewing at 1,000 lumens. Anything near 300 is a curtains-closed device, whatever the box shows.
Check power against your use. The MoGo 3 Pro has no battery and wants a 65 W USB-C source, which for a backyard movie means a portable power station rather than a phone charger.
The GV50 lists 22.4 ms input lag at 1080p 60 Hz, so if you plan to game on it, read our guide to cutting input lag on a big screen first. And if the built-in smart platform is sluggish, an HDMI stick such as the Firestick 4K sidesteps it on any of these.
Frequently asked questions
Is 9,000 lumens realistic for a mini projector?
Not under any published standard. The brightest compact model in this comparison, Epson’s EF21, is rated at 1,000 lumens under ISO 21118. A court found Yowhick’s 9,000-lumen claim measured below 1 percent of that figure.
Are ANSI lumens and ISO lumens the same thing?
ANSI adopted ISO 21118 as the US standard, so the two figures come from the same nine-point test and are directly comparable. “ISO lumens” is shorthand for a measurement the standard simply calls lumens.
Which mini projector is bright enough for a room with the lights on?
Of the four listed, only the Epson EF21 is rated by its maker for day or night use at 1,000 lumens. The 300 to 500 lumen models are specified for darker rooms and lose more light once you leave the brightest mode.
Vicki Lewandowski covers apps, consumer gadgets, and step-by-step digital how-tos for 3Zebras, with a focus on clear instructions that help readers fix problems and get more out of the devices they already own.