1068
their dispute continued for many years. Voigtländer,
however, went on to refi ne and develop the design, and
his ‘Orthoskop’ lens—a direct derivative of the original
design—achieved widespread success as a landscape
lens.
Recognizing the shortcomings of the original lens,
Petzval applied his mathematical skills to resolving
the problems of spherical aberration, and in so doing,
evolved a mathematical calculation to measure and pre-
dict the fl atness of the resulting image fi eld. The ‘Petzval
Condition’ or ‘Petzval Sum,’ derived in 1843, became
the standard method for quantifying this problem and
resolving its effect. It is still in use today.
Petzval is also credited with the design of opera
glasses, and therefore with contributions to the evolu-
tion of binoculars. He also proposed mirror refl ectors
for light bulbs, to gather and refl ect a higher propor-
tion of the available illumination, and made signifi cant
contributions to the worlds of mathematics, acoustics
and physics.
However, a break-in at his house in Vienna in 1859
resulted in the loss of many of his manuscripts—several
of them unpublished—and resulted in him abandoning
his plans to publish defi nitive books on the subject of
optics.
He retired from scientifi c pursuits in 1877, and died
in Vienna in 1891.
Caryn Neumann
Biography
Born in Spisská Belá–then in the Austro-Hungarian
Empire but today in Slovakia—Josef Petzval was one of
six children. His father was a teacher and musician. Josef
studied physics and later mathematics in the Institutum
Geometricum in Budapest, now part of Budapest Uni-
versity, and after graduation, with a doctorate in physics,
lectured part time at the Institutum, while also working
as an engineer in Prague. In 1838, he took up the position
of Professor of Mathematics in Vienna, where he spent
the rest of his professional career, retiring in 1877.
An intensely private man, relatively little is known of
his private life, and even his biographer Ludwig Erme-
nyi could offer little information. He is known to have
married late in life—in 1869 at the age of 62—but was
divorced four years later. In 1877 he moved to Kahlen-
berg of the outskirts of Vienna where he became a virtual
recluse and died in 1891, largely forgotten and almost
penniless. History, however, has not forgotten him.
Further Reading
Kingslake, Rudolf. Lens Design Fundamentals. New York:
Academic Press, 1978.
Smith, Warren J. Modern Lens Design: A Resource Manual. New
York: McGraw-Hill, 1992.PHILADELPHIA PHOTOGRAPHER
Under the editorship of Edward L. Wilson, The Phila-
delphia Photographer was established in 1864 with the
sponsorship of the Philadelphia Photographic Society.
Wilson had left business a year previous to work with
the Philadelphia photographer Frederick Gutekunst. The
journal was published twice-monthly, and distinguished
itself from the New York journals by including a tipped-
in photograph, varying from views, portraits and copies
of engravings, in each issue. The journal included one
of Edward Muybridge’s views of Yosemite in 1869. In
contrast to the more scientifi c concerns of The American
Journal of Photography and Humphrey’s, Wilson saw
the Philadelphia Photographer as serving a more gen-
eral readership, including the “novice, experienced artist
or amateur.” “No centre table is without its album, and
no parlor wall entirely bare of photographs. Yet how few
know how they are made; how to get the best or where;
which are the best kinds; or how to sit and what to wear,”
Wilson wrote in the fi rst issue. After 1869, The Phila-
delphia Photographer was the remaining independent
photography journal and the most infl uential journal in
the fi eld in the last decades of the 19th century.
Writers for the journal included Matthew Carey Lea,
chemist and scion of the Philadelphia publishing family,
who reported on and evaluated photographic chemistry
and wrote summaries of his reading of the British and
European photographic journals. In 1864 and 1865,
Coleman Sellers wrote a series “Letters to an Engineer,
On Photography as Applied to His Profession” that
traced the connection between industry and photogra-
phy; he also profi led Dr. Thomas Kirkbride’s use of the
Lagenheim brothers’ magic lantern slides displays at the
Philadelphia Hospital for the Insane. Hermann Vogel
regularly wrote a “German Correspondence” column
for the journal and reported on photographic events
in Europe beginning in 1865; during the 1870s, John
Towler, former editor of Humphrey’s, wrote a regular
column as well.
Technological and chemical reporting in the journal
ranges from wet and dry plates to discussions of magic
lantern slides, stereographs in the 1860s and 1870s. In
the 1860s, the journal published articles titled “Photog-
raphy as a Moral Agent” and “Photography and Truth.”
Wilson and his writers weighed in on discussions of
artistic view photograph in the 1870s, promoting the
artistic visions of photographers and their medium,
recommending in 1871 that Henry Peach Robinson’s
Pictorial Effect in Photography was the standard-bearer
in photographic literature. In the 1880s the journal gave