Bandpass Lens Filter 450nm, Select your size, 450 nm peak wavelength, useful range between 430-470 nm, useful range FWHM: 40 (±5 nm)

The BP450 narrow bandpass filter is a lens filter designed to pass light with a peak wavelength of 450 nm and a useful range between 430–470 nm, while blocking all other wavelengths.

It mounts directly on a machine vision lens using the standard filter thread.

You can choose from multiple thread sizes to match your lens, ensuring a secure fit and optimal performance in any machine vision setup. 

How the BP450 Narrow Bandpass Filter Works

Narrow bandpass filters work by allowing only a specific portion of the light spectrum to pass while blocking all other wavelengths.

For the BP450 filter, light near 450 nm passes through with peak transmission above 90%, and the useful range between 430–470 nm maintains transmission above 80%. 

Specification
Filter type	Narrow Bandpass
Peak wavelength	450 nm
Peak wavelength color	Blue
Useful wavelength range	438-470 nm

Our BP450 lens filter is available in different sizes:

Because lenses come in different sizes, the BP450 filter is offered in several common thread options so it can match both compact and larger lenses:

• C-mount filter

• 0.5 thread (pitch): M22.5×0.5, M25.5×0.5, M27×0.5, M30.5×0.5, M34×0.5, M35.5×0.5, M37×0.5, M37.5×0.5, M40.5×0.5

• 0.75 thread (pitch): M37×0.75, M43×0.75, M46×0.75, M49×0.75, M52×0.75, M55×0.75, M58×0.75, M60×0.75, M62×0.75, M67×0.75, M72×0.75

Want to use a C-mount (CMT) filter thread?

Just fill out the form below to get instant access to the manual on how to mount it and see which lenses it’s compatible with!

Narrow Bandpass Filter Overview and Applications

The BP450 bandpass filter is designed to transmit light centered around 450 nm while blocking unwanted wavelengths outside its passband. This precise wavelength control enhances image contrast, color accuracy, and measurement reliability for a wide variety of optical systems.

By selecting a specific wavelength (for example 450 nm), the BP450 filter effectively becomes a ‘color’ filter for the monochrome imaging: it allows only the target color (blue) to pass and suppresses its complementary and nearby wavelengths. Adding a color lens filter “works on a subtraction idea” — for instance, a blue filter makes blue shades stay bright while rendering complementary colors dark.

In practice, when you pair white-light or any broad-spectrum source with a BP450 filter, you are isolating only the precise band around 450 nm: the result is higher contrast, sharper object differentiation, fewer false reflections from ambient light, and improved image-stability. This is especially valuable in machine-vision inspections where subtle differences in material, color or surface need to be reliably detected under variable lighting conditions.

Typical Applications:

• Blue LED or laser lighting systems

• Surface or defect inspection 

• Fluorescence or color-based imaging 

Compatibility with Lenses and Cameras

The BP450 filter can be mounted on the front of most machine vision lenses, as these lenses include a filter thread for attaching filters directly.

If you are using a C-mount lens on a GigE camera or USB3 camera, the filter can also be placed inside the C-mount connection instead of on the front of the lens.

This is useful when the lens does not have a front filter thread.

The filter is installed between the camera and lens and stays fixed in the optical path, keeping alignment stable and image quality consistent.

This makes the BP450 filter flexible for different setups and easy to integrate without changing your existing camera or lens.

Key Benefits for BP450 Narrow Bandpass Filter:

• • High transmission at 450 nm
• • Strong blocking of out-of-band light
• • Improved image contrast and signal quality
• • Stable optical performance under varying conditions
• • Reliable results in precision imaging and measurement tasks

Choose Your BP450 Narrow Bandpass Filter

Select the BP450 narrow bandpass filter in the thread size that fits your lens. For assistance choosing the right size or wavelength, contact our technical team.