refracting telescope
refractor

He was the first American to make very large professional refracting telescopes.

At that time, it was the world's largest refracting telescope.

The final result was a 32-power refracting telescope, with which he made a series of major discoveries.

Refracting telescopes and their photographic images do not have the same problem.

The refracting telescope which uses lenses to form an image.

Lenses made this way are sometimes used as objectives in refracting telescopes.

It has the largest refracting telescope in the world.

It houses the second-largest refracting telescope in the state of Washington.

In some of the very long refracting telescopes constructed after 1675, no tube was employed at all.

Five times, the firm built the largest refracting telescopes, Great refractors, in the world.

They are free of chromatic aberration found in refracting telescopes.

The largest practical lens size in a refracting telescope is around 1 meter.

Winthrop also studied astronomy with his 3 foot refracting telescope.

The objective in a refracting telescope refracts or bends light.

The research facilities include everything from a 24-inch refracting telescope to a library with three-quarters of a million volumes.

Not until 1866 did refracting telescopes reach 18 inches (45 cm) in aperture.

You have just built a simple refracting telescope!

In 1993, the first refracting telescopes were produced.

From these experiments Newton concluded that no improvement could be made in the refracting telescope.

Lens sag is a problem that sometimes afflicts very large refracting telescopes.

Both reflecting telescopes and refracting telescopes are available in each category.

"It all began with a small, 40mm refracting telescope that my parents bought me as a present.

Refracting telescopes have long been regarded as the superior instrument for planetary observing.

The 76 cm refracting telescope is completed at Nice Observatory.

For some years the Newall was the largest refracting telescope in the world.

Because of this, large refractors seemed to be the better choice.

I turned and got the human in the range of my refractor bulb.

For a number of years Cooper's big refractor was the largest in the world.

But to travel across time with the help of a refractor is possible."

On the other hand a refractor is more costly, and in some ways less convenient to use.

His eyes stared at my refractor bulb as though he were trying to read something there.

With the achromatic refractor, however, this is not the case.

Could repeated use of the refractor result in nerve damage?

Only 241 of each Refractor were produced and continue to this day to be highly sought after.

A pair of binoculars is nothing more than two small refractors joined together.

However, they also have bigger refractors, thus spreading light more efficiently.

At last, he straightened and took off the refractor.

Finest issued a Refractors set available at 1 in every 18 packs.

It is housed in a building about 100 feet northwest of the Clark refractor.

No larger refractors could be built because of gravity's effect on the lens.

I have no nose or mouth, and only one eye, you might say - the refractor bulb in the middle of my control box.

The long tube of the refractor seemed to vanish into the gloom.

The 1890s therefore mark the end of the great refractors era.

Drew's first celestial observations were made with a three and a half foot refractor.

It is the fifth largest refractor in the world.

The choice of building large refractors over reflectors was a technological one.

He brought with him an optical tube assembly for a 6-inch f/15 refractor.

A soft tissue refractor is used to allow for greater visibility and access.

Collectors enjoyed the offerings of the set along with the refractor parallels.

It was a big instrument, a four inch refractor on a heavy tripod.