portrait-lens

Sometimes the adjustable portrait-lens, which can be slipped over the other, will obviate that trouble by blurring everything not in exact focus, and this lens will allow you to stand nearer the object and so make it larger on the film.

On the Trail An Outdoor Book for Girls Lina Beard 1888

College in March, 1888, with an 8-inch portrait-lens (the same used in the preparation of the Draper Catalogue) showed the old-established

A Popular History of Astronomy During the Nineteenth Century Fourth Edition 1874

The telescope used was of eight inches aperture and forty-five focus, its field of view -- owing to the "portrait-lens" or

A Popular History of Astronomy During the Nineteenth Century Fourth Edition 1874

Special conditions were required for success; above all, a wide field and a strong light-grasp, both complied with through the use of a 6-inch portrait-lens.

A Popular History of Astronomy During the Nineteenth Century Fourth Edition 1874

"In the photographs made with the 6-inch portrait-lens," Professor Barnard wrote, "besides myriads of stars, there are shown, for the first time, the vast and wonderful cloud-forms, with all their remarkable structure of lanes, holes, and black gaps, and sprays of stars.

A Popular History of Astronomy During the Nineteenth Century Fourth Edition 1874