When we think of the cosmos, most of us picture the colorful scenes of deep space — glowing red nebulae, bright blue stars, golden star fields. These long-exposure, visible-light images have shaped our impression of the universe for decades.
But here’s a question: is color the only way to see the cosmos?
The truth is, the universe extends far beyond visible light. It also shines in infrared, ultraviolet, and even radio waves. By stepping beyond the visible spectrum and into the near-infrared (NIR), we can reveal a hidden side of the night sky — one that cuts through city light pollution and shows the Milky Way in surprising detail.
Recently, “Near-Infrared Milky Way Photography” has been gaining popularity in the astrophotography community. Many astrophotography enthusiasts are already capturing the Milky Way from Bortle 7–9 skies using nothing more than guide cameras or planetary cameras. Let’s explore why near-infrared works so well under heavy light pollution, and which budget-friendly cameras can get you started.
Equipment: GPM462M+StellaVita
Location: Bortle 7-8 urban sky
Credit: Xiaowandou ZK
Equipment: GPM462M+StellaVita
Location: Bortle 9 urban sky
Credit: Mubeiluo
Equipment: G3M2210M+Fisheye Lens
Location: Under urban sky
Credit: Ye Ping
Why Near-Infrared Works in the City
The electromagnetic spectrum. Image Credit: Metrohm AG
Near-infrared (NIR) light is invisible light with wavelengths between 780nm and 2500nm. Urban light pollution primarily comes from sources like street lamps and neon lights. The shorter wavelength visible light emitted by these sources is scattered wildly by microdust and suspended particles in the night sky, illuminating the atmosphere and interfering with our observation of celestial objects.
Near-infrared light, with its longer wavelengths, is less easily scattered by dust and gas molecules in the air, allowing the atmosphere to retain a degree of "transparency" at these wavelengths. Furthermore, most urban lighting sources emit weakly in the near-infrared band, leaving a window of possibility for revealing the Milky Way's grandeur.
From an imaging principle perspective, the sensors in common cameras have different responses to various light wavelengths. In NIR imaging, specially designed sensors or cameras equipped with NIR-pass filters can more sensitively capture photons in the NIR band. When NIR light from the night sky reaches the camera sensor, the sensor converts photons into electronic signals, which are then processed to form an image. It's akin to fitting the camera with special "night vision goggles" that only let NIR light through, effectively filtering out the visible light interference from light pollution and revealing a purer starry sky.
How to Take an Infrared Milky Way Galaxy with GPM guide cameras?
The GPM662M/C are now on sale. Also, IR Cut and AR glass versions are provided for GPM662C. If you want to explore infrared photography, you can get the LP825 filter and adapter set and a CS lens as the early bird gift when ordering before October 11, 2025.
This infrared Milky Way Galaxy set eliminates the hassle of accessory compatibility, offering simplicity and ease of operation. Whether paired with StellaVita or ToupSky software, it allows you to effortlessly capture the beauty of the Milky Way even in light-polluted urban environments.
Using StellaVita
Step 1: In "Main Camera", select G3M series Planetary or GPM series guide camera (GPM462C as an example here). Choose "Video Mode".
Step 2: In Video mode, select a bright star and adjust "Gain" and "Exposure" until the star turns to the finest.
Step 3: Change to "Single Mode" and start to capture.
Using ToupSky
Download ToupSky at: https://www.touptek-astro.com.cn/downloads/?atfWidgetNav=box_win
Step 1: Connect your G3M series planetary or GPM series guide camera to the computer. Open ToupSky and the software will automatically detect the camera (using GPM462C as an example here).
Step 2: Click the name of the camera in the red box. Choose "Video Mode". Select a bright star and adjust "Gain" and "Exposure" until the star turns to the finest.
Step 3: Choose "Single Mode”, adjust "Exposure" and "Gain" until the target turns the clearest and finest.
Step 4: Save the image: click the image name and select the file type. The image will be saved locally.
Top Picks of Guide Cameras for Budget-Friendly Infrared Imaging
GPM662M/GPM662C
GPM662M/C are the new arrivals of the GPM series guide cameras. As the upgraded version of GPM462M/C, the new GPM662M/C features the SONY IMX662 sensor and outperforms in QE peak and infrared sensitivity, being perfect for capturing Milky Way in infrared and precise guiding.
| Model | GPM662M | GPM662C |
| Sensor | IMX662 Mono | IMX662 Color |
| Sensor Size | 1/2.8" | 1/2.8" |
| Resolution | 1920 x 1080 | 1920 x 1080 |
| Pixel Size | 2.9µm | 2.9µm |
| ADC | 12bit | 12bit |
| QE | >91% | >91% |
| USB | 2.0 Type-C | 2.0 Type-C |
| Dynamic Range | 75.2dB | 75.2dB |
| FPS | 17.8fps (8bit) | 7.8fps (8bit) |
| Max SNR | 45.3dB | 45.9dB |
| Full Well | 33.8ke- | 39.034ke- |
| Read Out Noise | 5.86 – 0.4 e- | 6.81 – 0.48 e- |
Equipped with a Sony IMX662 CMOS sensor, 2.9µm square pixels, and a 1/2.8-inch format, GPM662M and GPM662C guide cameras both offer a resolution of 1920x1080. They deliver excellent performance in the NIR band, capable of rendering fine details of the starry sky.
The GPM662M's G sensitivity is 8970mV at 1/30s and the GPM662C'S G sensitivity is 570mv at 1/30s. A higher value indicates stronger sensitivity and a more pronounced response to faint light signals. Even under the mixed lighting of urban nights, it can keenly detect light signals from the Milky Way.
Planetary Camera Recommendations
Beyond budget-friendly guide cameras, these 2 planetary cameras are also excellent choices for NIR imaging.
G3M2210M/G3M2210C
Features a 1/1.8" sensor with 4µm large pixels that enhance single-pixel photon capture capability. It is sensitive across the 350-1100nm wavelength range, with particularly excellent NIR-enhanced performance. Even under severe urban light pollution, it can capture faint details from an infrared perspective, while also delivering high-quality planetary images in the ultraviolet band.
SC2210 Monochrome Spectral Sensitivity Curve Chart
SC2210 Color Spectral Sensitivity Curve Chart
G3M678M/G3M678C
Equipped with a Sony IMX678 monochrome or color sensor, it offers 3840x2160 high resolution and 2.0µm pixels, with a spectral response range of 380-1100nm. It achieves high frame rates up to 1500fps at 8-bit and 3840x40 resolution, making solar, lunar, and planetary photography more efficient. The 1/1.8-inch format often eliminates the need for a Barlow lens when used with long focal length telescopes for planetary imaging, and requires fewer panels for large mosaics.
IMX678 Monochrome Spectral Sensitivity Curve Chart
IMX678 Color Spectral Sensitivity Curve Chart
Monochrome vs. Color IR Imaging: Which is Right for You?
Monochromo cameras
- Maximized Light Efficiency, Higher SNR
Color cameras use a Bayer filter array, which limits photon incidence (only ~25% of pixels correspond to red visible light). Monochrome cameras have no such limitation; all pixels are utilized directly. Thus, under the same conditions, they collect a stronger signal from the light source and achieve a higher Signal-to-Noise Ratio (SNR).
- Precise Detail, No interpolation Artifacts
Monochrome images are derived directly from pixel values without Demosaic interpolation processing, resulting in higher spatial resolution and sharpness. This offers distinct advantages, especially for identifying faint Milky Way structures and dust textures.
- Multi-band Imaging, Flexible Combination
Using a monochrome camera allows for the use of various narrowband filters (e.g., SII, Hα, OIII). Not only can you capture deep-sky objects within the visible spectrum, but by switching to an infrared filter, you can pierce through light pollution to appreciate the Milky Way's brilliance and hidden star fields. Although the process is more complex and time-consuming, combining images from these different perspectives can maximize interesting effects, like having nebulae and the Milky Way share the frame.
Color cameras
- Ready to Use, Quick Results
Color cameras provide color output directly out of the box, requiring no filter wheels or multi-channel combination. This is particularly suitable for fast-paced operations and intuitive imaging needs for beginners.
- Efficient Use of Clear Skies
When clear sky time is limited, directly capturing a color Milky Way image is more efficient than using a multi-channel monochrome setup.
- Comparable IR performance to Mono
For infrared photography, especially at wavelengths above ~800nm, sensors like the IMX462/662 utilizing STARVIS technology benefit from the three-color Bayer filters having nearly identical high transmittance for IR light. This effectively allows near-full pixel photosensitivity, achieving results extremely close to those of a monochrome camera.