NIGHTSEA focus lens for light heads

The focus lens is an add-on for the NIGHTSEA SFA light heads to produce a higher illumination intensity. This simple adapter slips over the front of the light head and grips with a friction fit. It is available with two options for the focal distance: 30mm or 50mm.

• No lens ? illumination spot approximately 15mm diameter with the light head positioned 50mm from the surface
• 50mm lens ? central spot approximately 5mm diameter, intensity increase ~2x
• 30mm lens ?  central spot approximately 2mm diameter, intensity increase ~3.5x

The images below show the focus lens add-on and the effect. The three illumination spot images were made in manual exposure mode and are indicative of the relative intensity.

Considerations for lens choice:

• To gain the benefit of the 30mm lens it is necessary to position the light head very close to the subject. This may be challenging in the tight space beneath a microscope objective. It might be more suited for photoactivation, where a high light intensity dose in a small area is often needed.
• The 50mm lens provides a trade-off ? brighter fluorescence, easier to work with.

Note ? If the light head has a snoot installed that will have to be removed to use the focus add-on.