The sciopticon manual, explaining lantern projection in general, and the sciopticon apparatus in paricular (1877)

Record Details:

Title:
The sciopticon manual, explaining lantern projection in general, and the sciopticon apparatus in paricular
Date:
1877
Publisher:
Philadelphia, J. A. Moore
Volume:
The sciopticon manual, explaining lantern projection in general, and the sciopticon apparatus in paricular
Leaf #:
00031
Language:
English
Collection:
Books
Format:
Books
Contributor:
University of California Libraries
Sponsor:
MSN
Coordinator:
Media History Digital Library
Description:
Date Added:
July 19, 2022
Something wrong or inaccurate about this page? Let us Know!

Thanks for helping us continually improve the quality of the Lantern search engine for all of our users! We have millions of scanned pages, so user reports are incredibly helpful for us to identify places where we can improve and update the metadata.

Please describe the issue below, and click "Submit" to send your comments to our team! If you'd prefer, you can also send us an email to mhdl@commarts.wisc.edu with your comments.




We use Optical Character Recognition (OCR) during our scanning and processing workflow to make the content of each page searchable. You can view the automatically generated text below as well as copy and paste individual pieces of text to quote in your own work.

Text recognition is never 100% accurate. Many parts of the scanned page may not be reflected in the OCR text output, including: images, page layout, certain fonts or handwriting.

22 SCIOPTICON MANUAL. Among the modified forms, the Dallmeyer Landscape Lens, which consists of three lenses" cemented together, a central one of flint-glass and two outer ones of different kinds of crown-glass, gives better results. The stop B B is generally one-fifth of the focal length distant from the lens, and consequently cuts off much of the light. In the earlier days of photography a person had to sit in front of such a lens, in a strong light, for several minutes. That in this way no artistically perfect pictures could be made is self-evident, and so it became necessary for portrait photographers to have a lens that would work satisfactorily with a larger opening. THE PORTRAIT OBJECTIVE. This invention is no accident, but the result of a thorough theoretical calculation. It is a double ob- jective with two unequal lenses, with or without central stops between. \ Fiff. 13. The front lens A consists of a biconvex crown, and an almost plano-concave flint-glass lens, cemented to- gether with Canada balsam. The back lens B consists