NIGHTSEA Fluorescence Adapter for Keyence VHX-Series for ZST, various wavelengths

The NIGHTSEA™ Fluorescence Adapter system adds a versatile fluorescence imaging capability to the Keyence VHX series of digital microscopes. The system is being used successfully by a growing number of Keyence owners for a variety of applications.

Add-On Light and Filter set are available for various excitation/emission wavelengths. Thereby, LED Light heads and filters can be removed and replaced in seconds.

The NIGHTSEA Fluorescence Adapter for VH-ZST lens include:

• Excitation light source with filter
• Slot emission filter - easy to insert
• Emission filter goggles
• Gooseneck LED base with dimming control and power supply: 120/240VAC - 50/60Hz, with international plug set)
• Adapter and BNC cable for mounting the LED light head at the fiber optic port of the VH-ZST lens for enhanced performance at high magnifications
• Soft-case for storage and transport

Filter sets available for the following wavelengths:

Dimmable gooseneck base with LED light head
The illumination intensity can be adjusted at the base of the gooseneck. The LED light head is equipped with a BNC connector, which can be attached to the BNC socket at the end of the gooseneck and quickly replaced.

Slot emission filter
The slot emission filter is inserted into the existing Analyzer slot of the VH-ZST lens. Due to the size of these lenses and the small working distance at high magnifications, the ring emission filter is not suited.

Emission filter goggles
The filter goggles spectrally match the respective emission filter. They serve as eye protection against the bright excitation light but are also suitable for viewing the fluorescence directly by eye.

Performance expectations
Keyence VHX microscopes are not designed for fluorescence. That said, the NIGHTSEA™ adapter system adds a fluorescence capability that is proving to be valuable for a growing number of users. Several companies have purchased multiple adapters so that they could replicate the performance across multiple microscopes. However, the NIGHTSEA™ adapter system does not replace a fluorescence microscope.

Enhanced performance with the VH-ZST and limitations
At higher magnifications (200 – 2000x), the VH-ZST objective achieves enhanced performance by replacing the Keyence fiber optic port with the NIGHTSEA excitation light head using the adapter provided. Thereby the excitation light is directly guided through the lens creating a much more concentrated illumination spot, than achieved with the light source positioned on the side. With this configuration fluorescence images up to 2000x magnification are achievable.

Unfortunately, the fiber optic port built into the lens seems to block quite a bit of UV light. The result is that the focused spot is not particularly strong. For our UV light source, it is recommended to apply the light from the side for all magnifications. This will impose some limit on achievable magnification that will be a function of the fluorescence intensity. There are also alternatives to consider to ultraviolet – many of the fluorescent materials used in industrial applications, such as the dye penetrants and epoxies used for highlighting cracks and separations or for concrete thin sections, fluoresce very well under Royal Blue excitation, while conformal coatings on circuit boards fluoresce well under Violet excitation.