The photo shown is taken from the "Foto-Magazin" No. 11/1954 which shows the horizon to be an optical illusion. Dr. Fritz Neugass comments, quote: "A new Tele-Objective of the US-Army" The optical research division of the US-Army Signal Corps has just issued a new camera, which is specially suited to take photos at a distance of 50 km (30 mi.). The objective has a focal length of 254 cm (100 in.), it is 1 m long and has a diameter of 24.13 cm (9.5 in.), it has been corrected for using infra-red film.

Using this objective it is quite easy to analyze the terrain up to a distance of 10 to 20 km (6-12 mi.) and distinguish weapons, fortifications and transports. The disadvantage of such a teleobjective is the complete elimination of perspective.
The photo reproduced, shows the Empire State Building and the outlines of Manhattan at a distance of 41.8 km (26 mi.)
At the bottom of the Empire State Building a large hotel is visible on Coney Island, however, it is only 20.9 km (13 mi.) distant from the camera.
One could never tell from this photo that between these two buildings there is a distance of 21 km .
The lighthouse of Sandy Hook, in the foreground of the photo is only 6.4 km (4 mi.) distant from the camera.

The new teleobjective is coupled to a 13 x 18 cm camera which can either use film cassettes or rolls of film. Each roll of film contains 30 exposures, however, a built-in cutter can be used to cut off exposed parts of the film.
They can be lifted out with the take-up spool. The shortest distance to still produce a sharp photo with this teleobjective is 500 m (1 600 ft.) In this case the width of the photo covers 31 m (100 ft.) At a distance of 20 km (12 mi.), which is the last point before infinity, the section of the photo covers about 1 000 m (3300 ft.)
The telescope, which is used to focus the camera has a magnification of 10 and shows the exact frame of the photo to be taken. When adjusting for the proper distance, the heavy objective, which is firmly mounted on the tripod, is not moved, but instead one only moves the camera.
The device weighs about 64 kg (140 lb.) and must be operated by two men. The whole camera is carried, with two handles each on front and back, like a stretcher. The device can be set up, aimed and adjusted, all within 5 minutes. End of quote.

Studying the entire photograph we can determine the following:

[1] The camera is at the beach of Atlantic Highlands about 1m (39 in.) above ground level.

[2] The camera, as well as the telescope is directed upwards, which shows that the photo was not taken from any elevated point, and that any objects behind the horizon must be situated higher.

[3] An island being 6 km (4 mi.) distant is shown in its entirety (looking down on it). The sea inlet behind it, 14 km wide (9 mi.), as well as the wharves of the Coney Island harbor are shown without being covered.

[4] That is not all. The photo allows a view of the roofs of the harbor city behind it, optically includes the peninsula Brooklyn and another sea inlet and clearly shows the skyscrapers of Manhattan.
If this earth were a convex solid ball, and light rays would travel perfectly straight, all this should be 100 m (330 ft.) below the horizon.