To control the focus of the light, a Fresnel lens was used.

A last check showed the Fresnel lens was still green.

The front light was a white, fifth order Fresnel lens.

Fresnel lenses have also been used in the field of popular entertainment.

The fifth order fresnel lens came from the original front range light.

The tower used to be white with a red band and had a Fresnel lens.

The light was concentrated and focused with a system of Fresnel lenses.

There are many light houses, some with detailed Fresnel lenses.

In 1857 the light was equipped with a fourth order Fresnel lens.

The tower later became the first to use the revolutionary Fresnel lens, in the early 1820s.

It had a fourth order Fresnel lens, and the light could be seen sixteen miles away.

The optic system is still the original first order Fresnel lens.

The original oil house now contains a Fresnel lens exhibit.

A 4th order Fresnel lens was housed in the small light compartment.

The lighthouse was built in 1906 and had a fourth order Fresnel lens.

The light was a first-order Fresnel lens which stood 134 feet above the water.

The original Fresnel lens was installed in the new tower.

The light is usually covered by a Fresnel lens.

On top of the box is a large fresnel lens that collimates the light.

The Fresnel lens from the light is on display inside the museum, along with other lenses used in the area.

The tower was originally lit with a 5th order Fresnel lens.

Compared to earlier lenses, the Fresnel lens is much thinner.

And with its traditional Fresnel lens, it is visible from 18 nautical miles.

The original Fresnel lens is housed in the lighthouse museum.

Originally the new light was given a fifth-order fresnel lens.