Which telescopes does the 300 mm panel suit?

Ones too wide for the 150 mm size, up to a front that fits under the 300 mm lit area.

Does the Gemini Flat Panel Lite 300 mm work with NINA?

Yes. Gemini supplies ASCOM and INDI drivers and a Windows app for the Lite, and NINA sets the brightness through the ASCOM driver.

Why two brightness modes?

Narrowband filters pass far less light than broadband ones, so the high mode serves narrowband and the low mode broadband, each with 256 steps.

Does it need a power supply?

No. One USB cable carries both the 5 V power and the brightness control, and Gemini says it draws under 5 W at full brightness, so a laptop, a USB charger or a power bank runs it.

Where can I buy the Gemini Flat Panel Lite 300 mm?

The prices I recorded: $72 at AliExpress, Gemini Outdoor Store (Global), listed.

Gemini Flat Panel Lite 300 mm review: flats for wide scopes

Where does it rank on our leaderboard

Nine of the 46 accessories on my board, against price
Rank	Accessory	Stars for Your Buck	Recorded UK price
1	GEMINI EAF	100 out of 100	£42
2	Generic Dew Heater	93 out of 100	£9
3	SVBONY Guide Scope 30mm f/5	93 out of 100	£57
15	Flat Panel 300mm	78 out of 100	£54
21	365 Telescope Cover	74 out of 100	£209
29	Star Analyser 200	63 out of 100	£137
42	Celestron Binoviewers	40 out of 100	£242
45	SKY ROVER 2x54 Binoculars	28 out of 100	£139
46	365 Solar Telescope Cover	5 out of 100	£73

Contents

01 Where does it rank on our leaderboard
02 Specifications and features
03 Should you buy it?
04 Questions and more about this review

In 30 seconds

Stars for Your Buck 78/100

Written 26 Sep 2026 Updated 26 Sep 2026

Rank: #15 of 46 accessories
Verdict: Damon recommends

Written by Damon Scotting 3 min read

Buy it if

Your telescope's front is too wide for a 150 mm panel.
You want the same light for your flats every night, whatever the dusk sky is doing.

Skip it if

Your telescope fits under 150 mm: the smaller panel is lighter and easier to carry.
You already make flats you are happy with from a light box or the dusk sky.

Gemini's Flat Panel Lite at 300 mm, for telescopes too wide for the small sizes: a USB-powered panel with a steady light for flat frames, dimmable in 256 steps from NINA, the Windows app or the remote.

AliExpress $72 Ad

Specifications and features

Against the accessories I have reviewed

Compare with

Gemini Flat Panel Lite 300 mm reviewed #15 of 46	Flat Panel 150mm #22 of 46
Recorded UK price	£54	£50
Stars for Your Buck	78/100	73/100
Model	Gemini Flatfield Panel Lite	Gemini Flatfield Panel Lite
Illuminated aperture	300 mm	150 mm
Lite sizes	150, 190, 240, 300, 330 and 400 mm	150, 190, 240, 300, 330 and 400 mm
Power	5 V over one USB cable, under 5 W at full brightness	5 V over one USB cable, under 5 W at full brightness
Dimming	0 to 255 levels in a high brightness mode and a low brightness mode	0 to 255 levels in a high brightness mode and a low brightness mode
Modes	High brightness for narrowband filters, low brightness for broadband	High brightness for narrowband filters, low brightness for broadband
Control	ASCOM and INDI drivers, a Windows app, an infrared remote, and Wi-Fi on the v2	ASCOM and INDI drivers, a Windows app, an infrared remote, and Wi-Fi on the v2
Flicker	Flicker-free at every shutter speed, by Gemini's figures	Flicker-free at every shutter speed, by Gemini's figures
Materials	Carbon fibre and aluminium	Carbon fibre and aluminium
In the box	The panel, a 1 m USB cable and an infrared remote (its CR2032 battery not included)	The panel, a 1 m USB cable and an infrared remote (its CR2032 battery not included)

Should you buy it?

78/100 Stars for Your Buck

Pros

One USB cable carries the power and the brightness control at 5 V: no mains adapter, and under 5 W at full brightness.
Brightness in 256 steps, in a high mode for narrowband filters and a low mode for broadband.
ASCOM and INDI drivers, so NINA and other capture programs set the brightness for you.
An infrared remote sets the brightness without a computer.
Flicker-free at every shutter speed, by Gemini's figures.
Carbon fibre and aluminium build.

Cons

A 300 mm panel is a large, flat thing to carry and store beside a small rig.
First Light Optics does not list it; it comes through AliExpress.
The AliExpress listing offers several sizes and versions, so check that 300 mm is selected before you order.
The remote's CR2032 battery is not in the box.

The same dimmable Lite panel sized for wide telescopes: 300 mm of steady light on one USB cable, set from NINA or a remote.

Three alternatives

Questions and more about this review

Reviewed by

Damon Scotting

The Telescope Man Verified

BSc (Hons) Physics with Astrophysics and Cosmology, Loughborough University PGCE / QTS, University of Nottingham

About Damon About Damon Damon Scotting is The Telescope Man. He holds a BSc (Hons) in Physics with Astrophysics and Cosmology from Loughborough University and a PGCE with QTS from the University of Nottingham, and taught physics in secondary schools before becoming an astronomy creator. He is a contributing writer for BBC Sky at Night Magazine and the author of 42 Wonders of Our Night Sky, and his photograph of the galaxy M100 with the dwarf planet Ceres was Highly Commended in the Astronomy Photographer of the Year 2024 competition run by Royal Observatory Greenwich. He has appeared on the BBC's Blue Peter. More than 750,000 people follow his astronomy channels on YouTube, Instagram and TikTok, and he has reviewed more than 140 telescopes, mounts, cameras, filters and accessories hands-on for this site. More about Damon · How I test · Damon's book

I review all kinds of gear: most of it I buy, some is gifted and some is loaned, and all of it is reviewed the same way. How this site is funded

Five questions, answered

Questions about the Gemini Flat Panel Lite 300 mm

Written 26 September 2026 ·Updated 26 September 2026

I review all kinds of gear. Most of it I buy, some is gifted and some is loaned, and all of it is reviewed the same way: no company sees or approves a review before it is published. Shop links marked Ad are affiliate links: I earn a commission when you buy through them, at no extra cost to you. How this site is funded

Which telescopes does the 300 mm panel suit? Ones too wide for the 150 mm size, up to a front that fits under the 300 mm lit area. The specifications and the comparison table ↓
Does the Gemini Flat Panel Lite 300 mm work with NINA? Yes. Gemini supplies ASCOM and INDI drivers and a Windows app for the Lite, and NINA sets the brightness through the ASCOM driver. The specifications and the comparison table ↓
Why two brightness modes? Narrowband filters pass far less light than broadband ones, so the high mode serves narrowband and the low mode broadband, each with 256 steps. The specifications and the comparison table ↓
Does it need a power supply? No. One USB cable carries both the 5 V power and the brightness control, and Gemini says it draws under 5 W at full brightness, so a laptop, a USB charger or a power bank runs it. The specifications and the comparison table ↓
Where can I buy the Gemini Flat Panel Lite 300 mm? The prices I recorded: $72 at AliExpress, Gemini Outdoor Store (Global), listed. A record, not a live price The verdict, the readers and the sellers ↓