Manhattan Optical Co.

Date Introduced: – ; Years Manufactured: c. 1903 – c. 1909
Construction: front and rear focus via rack and pinion (two gear tracks on top of base rails); double swing; shifting front, reversing by removable back; detachable rear extension
Materials: mahogany body, cherry base, nickeled brass hardware, red leather bellows
Sizes Offered: 4×5, 5×7, 6.5×8.5, 8×10
Notes: In 1899, Manhattan Optical made separate front focus only (Variation 1) and back focus only (Variation 2) versions. They were replaced by 1903 with Variation 3:  front and back focus.
References: 
1903 Koronas, Gundlach-Manhattan Optical Co., (Rochester, NY) Catalog, 1903, p. 40
Korona Cameras, Gundlach-Manhattan Optical Co. (Rochester, NY), Jan 1 1906, pp. 21-22
Korona Cameras, Gundlach-Manhattan Optical Co. (Rochester, NY), 1907
Korona Cameras, Gundlach-Manhattan Optical Co. (Rochester, NY), 1908
Photographic Supplies and Cameras 1909-1910, Sunset Photo Supply Co. (San Francisco, CA) Catalog, 1909, pp. 37