182. Telephoto Exposure

Telephoto Exposure. The amount of exposure to be given where the regular telephoto lens is employed, may be very easily reckoned by referring to the table given in Volume VI, in Chapter XLII (Telephotography), Telephotography. As a rule, where the image is doubled in size, giving you four times the area, you will require four times the exposure that would be necessary from the same point of view with the doublet or complete lens.

183. Adjustable Tripod Top For Details

Adjustable Tripod Top For Details. For some detail work the camera has often to be tilted considerably and in such cases a tilting tripod top should be employed. With this attachment any amount of tilt, even to a perpendicular position, may be obtained, without fear of the apparatus collapsing. See Ilustration No. 1.

the camera and lens pointed upward for bosses or ceiling details, a tilting, or adjustable, tripod top is a great convenience, for all detail work requires a visual inspection of the focusing screen to secure sharpness. In the absence of a tilting tripod top, when the object allows of a lens of normal focus being used, the camera can be taken off the tripod and simply placed lens upward on a table or even on the floor, when it should be carefully leveled in both directions horizontally. The focusing scale must, of course, be used in a case of this kind.

184. Ceiling Detail

Ceiling Detail. If much work is to be done with

Architectural Detail 090049

Photo by T. E. Dillon

Illustration No. 46

Interior - Ceiling Detail

See Paragraph 186

Interior   Ceiling Detail

Photo by T. E. Dillon.

Illustration No. 47

Interior - Ceiling Detail

See Paragraph 186

Architectural Detail.

185. Methods Of Focusing

Methods Of Focusing. If your camera is not equipped with the focusing scale, estimate the distance from the ceiling to where the lens will be when making the exposure; then focus the camera on some object located at an equal distance. Leave the lens set at this position, and then place the camera on the floor or table, or whichever distance you have estimated from, to secure the view you desire to include.

186. Two examples of ceiling detail are shown in Illustrations Nos. 46 and 47; the former is taken with a rapid rectilinear lens of 16-inch focal-length, stopped to U. S. 64; the plate used was a 11 x 14 Standard Orthonon with a twenty minutes exposure. The other example was made with the same lens fitted with a Bausch & Lomb ray filter. The lens was stopped to U. S. 32; the plate used was a Standard Orthonon; exposure given, 10 minutes. When photographing the dome the tilting tripod attachment was used, owing to the necessity of having to focus very accurately. The other view, however, being 12 feet from the floor, the camera was focused on an object 11 feet away, and when placed on the floor with the lens pointing upward a perfectly sharp image was secured, without any great amount of stopping down of the lens. For further data regarding how the picture was made, see department, How Studies were Made.