436 examples of lens in sentences

The eye which was thus brilliantly illumined looked through a lens of some power.

In the centre of the floor and in that of the roof respectively I placed a large lens of crystal, intended to act as a window in the first instance, the lower to admit the rays of the Sun, while through the upper I should discern the star towards which I was steering.

I placed a similar lens in the centre of each of the four sides, with two plane windows of the same material, one in the upper, the other in the lower half of the wall, to enable me to discern any object in whatever direction.

This mirror was to receive through the lens in the roof the image of the star towards which I was steering.

In truth, I should say that the various disadvantages due to the atmosphere deprive the astronomer of at least one-half of the available light-collecting power of his telescope, and consequently of the defining power of the eye-piece; that with a 200 glass he sees less than a power of 100 reveals to an eye situated in space; though, from the nature of the lens through which I looked, I cannot speak with certainty upon this point.

While watching this phenomenon through the lower lens, I thought that I could perceive behind or through the widest portion of the halo a white light, which at first I mistook for one of those scintillations that had of late become scarcely discernible.

I was about to turn again to the interesting work of observation through the lens in the floor, when my attention was diverted by the sight of something like a whitish cloud visible through the upper window on my left hand.

In a few hours the nebula so changed its form and position, that, being immediately over the portion of the roof between the front or bow lens and that in the centre of the roof, its central section was invisible; but the extremities of that part which I had seen in the first instance through the upper plane window of the bow were now clearly visible from the upper windows of either side.

Presently it came in view through the upper lens, but did not obscure in the least the image of the stars which were then visible in the metacompass.

For some little time after this the Earth was entirely invisible; but later, looking through the telescope adjusted to the lens on that side, I discerned two very minute and bright crescents, which, from their direction and position, were certainly those of the Earth and Moon, indeed could hardly be anything else.

I speak of descent, but, of course, I was as yet ascending just as truly as ever, the Sun being visible through the lens in the floor, and reflected upon the mirror of the discometer, while Mars was now seen through the upper lens, and his image received in the mirror of the metacompass.

I speak of descent, but, of course, I was as yet ascending just as truly as ever, the Sun being visible through the lens in the floor, and reflected upon the mirror of the discometer, while Mars was now seen through the upper lens, and his image received in the mirror of the metacompass.

As magnified by the telescope adjusted to the upper lens, the distinctions of sea and land disappeared from the eastern and western limbs of the planet; indeed, within 15° or an hour of time from either.

Fiction: a lens of life.

The factors which govern exposure are: the subject of the picture, the lens and its aperture, the rapidity of the plate, and last, but not by any means least, the quality of the light by which the work is to be done.

Scarcely two subjects will be found to send exactly the same amount of light through the lens.

Before we do anything more in this direction, we must consider the influence of the lens and its diaphragms.

In theory the single landscape lens is more rapid than the doublet of equal aperture, but the difference is so little that it may be disregarded in practice, and my remarks will apply to both.

Thus a lens of twelve inches focus will require four times the exposure of a six inch, with an equal sized diaphragm, and a quarter inch diaphragm will require four times the exposure of a half inch when used in the same lens.

Thus a lens of twelve inches focus will require four times the exposure of a six inch, with an equal sized diaphragm, and a quarter inch diaphragm will require four times the exposure of a half inch when used in the same lens.

The first two in his table will only be found in portrait lenses, but we shall probably find one to correspond with the third, if we are using a doublet lens; with a single lens we won't find any so large.

By placing in front of the lens a color-screen consisting of a small glass tank containing a weak solution of bichromate of potash, to cut off part of the blue and violet light, I obtained, with these chlorophyl plates, the first photographs in which all colors were reproduced in the true proportions of their brightness.

I place the tank in front of the lens, in contact with the lens-mount.

Carefully remove an eye and divide it behind the crystalline lens, put the posterior portion in a solution made by dissolving fifteen grs.

The lens should be put in the same solution, but should remain a few days longer.

436 examples of  lens  in sentences