US988710A - Foreground ray-screen. - Google Patents

Description

UNITED STATES PATENT OFFICE.

Jona a nomaaoox, or NEWARK, New sanear, assigner, ro es oaea incarna, me.,

0F NEW 'YOBL 1N. Y.

roaaenounn aar-scarsi?.

Specification of Letters ratei-it.

Patented Apr. 4, 1911.`

To all whom it may commi:

Be it known that I, JHN K. Houmoox, a citizen of the United Stateand a resident of Newark, in the county of ssex and State of New Jersey, have invented a new and Improved Foreground Bay-Screen, of which the following is a full, clear, and exact descri tion.

is invention relates to a foreground ray screen for cameras or other pieturestaking devices.

It is a well known factlthat in taking )lioto hs of landsca on a bright sunny i ny, t e right blue o the sky -affects the .sensitive plate or film ten or more times as quickly as the grass and trees, so that gen' orally an overexposed picture of the clouds is necessary, to obtain ood detail of the grass and trees, or, on t e other hand, the under-exposure of the grass and trees is necessary, in order to obtain a detail exposure of the clouds and sky.

An object, therefore, of this invention is to provide a. device which will retard those rays which Aact on the sensitized'plate or film qiiickt, and thereby obtain a photograph in vhich the detail throughout will be just rig it.

A further object of this invention is to provide a device which will be simple in construction inexpensive to manufacture, strong, durable, and readily adjusted.

These and further objects, together with the construction and combination of parts will be more full described hereinafter an particularly set orth in the claims.

Reference is to be had to the accomparing drawin formin a part of this spec cation, in w ich s ar characters. of reference indicate corresponding parts in all the views, and in which- Fi re 1 is a front view in elevation of one crm; Fig. 2 is a vertical section through the screening member of either form; Fig. 8 is a front view in elevation, partly in'section, of another form; and Fi 4 is a vertical section through the form ilustrated in Fig. 3.

Referrin more particularly to' the separate arts, represents a holder of any form suita le to t over the end of thelens hood of a camera, and may be removably secured thereto by a plurality of inwardl extending sprin grips 2 provided with ru ber covers 8. The holder isprovided, in both forms, with a filter or screening member 4, which lby a layer or in the case of the form illustrated in Fig. 1 is immovable and preferabl of a circular shape. In both forms, the ii tering member 4 consists, as will be more clearly seen by reference to Fi 2,'of a pair of sheets 5 and 6 of any suitab e transparent material, such as glass, havin parallel faces spaced apart 1m of colloidal material 7, such as cement, said layer of cement con taining a coloring matter of a yellowish or 'amber tint.

It willbe noted that the layer 7 is'wedgeshaped, being thickest at the top and tapering gradua y downward to microscopic thinness at t e bottom'. The difference in thickness of this colored cement is siifiicient to give a screen of the required colored density at the top and of the required clearness at the bottom, with a gradual variation between the top and the bottom. The thick-.

ness however, of the cement layer, even at its thickest point at the top is about eight to ten thousandths of an inch, so that this wedge shape, while giving the desired color variation, does not produce any undesirable prismatic eii'ect.

In the case of the form shown in Fig. 3, the variation in color effect is spread out over a distance considerably dimensions of the lens to which the device is applied and the screening member is made a Justable', so that any portion thereof can be brought into 'coperative relation with the lens, thus adaptin the device to be adjusted to various con itions where rester or lessscreenin etlect is desired. or this purpo the ho der 1 is extended on either side, an is provided with bent-over fianes 8, which form ways between which t e screening member 4 is ada ted to slide. The ways themselves may suiiiciently tight to hold the screening member in any a justed position, or an auxiliary spring 9, concealed within one of ,the ways, may-be provided for this purpose.

While- I have shown two embodiments of my invention, I do not wish to be limited to the specific details thereof, but desire to be protected in various changes', modifications and alterations which I may make within the scope of the a pended claims.

Having thus escribed` my invention, I claim as new and desire to sedare by Letters Patent:

1. A ray screen for a camera, adapted to ater than the modify the action .of the light comin therethrough, comprisin a plurality of s eets of transparent materia and a layer of cement interposed between said sheets and adapted to secure said' sheets together, said layer tapering gradually. from one edge of the sheets to t e opposite edge.

2. A ray screen for a camera, adapted to modify the action of the light comin therethrough, comprisin a plurality of s eets of transparentmateria and a layer of cement interposed between said sheets and adapted to secure said sheets together, said layer ta ring (gradually from one side to the ol er, an having a ray-filtering coloring t ierein.

20 transparent material, and a ayer of colessmo y loidal material interposed between said sheets, said layer tapering gradually from one side to the other.

4. A ray screen for -a camera, adapted to modify the action of the light comin therethrough, comprising a. plurality of s eets of ltriis arent material, a'nd a ayer of co1- o ia sheets, said layer tapering gradually from one side to the other and having a ray-filtering coloring, whereby certain rays of light have their rate of travel changed in passing .through the screen.

In testimony Vwhereof I ha've signed my material interposed between said' name to this specification in the presence of 35 two subscribing witnesses.

JOHN K. HOLBROOK. Witnesses:

F. W. HANAFonD, PHILIP D. RoLLHAUs.

Images