AntiqueCameras.net

The Petzval Lens

 

By

Dan Colucci[AS1] 

Illustration of Petzval’s lens design. Published on page 51 in Photographic Optics: A Text Book for the Professional and Amateur by William Kinnimond Burton, published by The Scovill & Adams Company of New York in 1891.

Origins

The daguerreotype process was briefly mentioned to the general public in France on January 2, 1839 in an article published in the semi-weekly newspaper, Le Drapeau Tricolore, based in Chalon-sur-Saône.[1] A much more detailed article followed in the Parisian newspaper, La Gazette de France, on January 6, 1839.[2] The latter article contained excerpts from a press release written by François Dominique Arago, a renowned physicist, astronomer, and secretary of the French Académie des Sciences (Academy of Sciences) who decided to champion the remarkable daguerreotype process.[3] The following day, Arago revealed to members of the academy the permanent images that Louis-Jacques-Mandé Daguerre had created after his many years of experimentation using his eponymous process.

Arago was instrumental in convincing the French government provide Daguerre and his partner Isidore Niépce pensions in exchange for making the daguerreotype process public and free of patent everywhere in the world, save for England where a patent and licensing arrangement was established (British Patent 8,194, applied for on August 14, 1839).[4] Isidore Niépce was the son of Daguerre’s late partner, Joseph-Nicéphore Niépce. Upon his death in 1833, Isidore replaced his father as Daguerre’s partner. With Daguerre and Niépce’s financial future thus secure, on August 19, 1839 Arago—with Daguerre and Niépce present—publicly presented the steps involved in Daguerre’s revolutionary process for making permanent images.[5] The lecture was held at a meeting of the Académie des Sciences, and members of the Académie des Beaux-Arts (Academy of Fine Arts) were also invited to attend.[6] This was the “great moment when photography was, at long last, given to the world.”[7]

The international scientific and artistic community, particularly in Europe and the United States, immediately embraced the process.[8] The ability to permanently capture and record the visible world in precise detail was an astonishing revelation.[9] Edgar Allan Poe commented in January 1840, “The instrument [the daguerreotype] itself must undoubtedly be regarded as the most important, and perhaps the most extraordinary triumph of modern science.”[10]

Although Daguerre received a pension for divulging his process, he capitalized further on the invention by entering into various business arrangements to manufacture and sell the equipment needed to produce daguerreotypes. On June 22, 1839, he executed a contract with his brother-in-law Alphonse Giroux to sell all of the equipment needed to create daguerreotypes, including a camera Daguerre personally designed known as the Giroux apparatus. At the time Giroux, who had assumed leadership of his father’s highly successful business in 1838, sold “pictures [paintings], stationary, and curios.” The firm was called Chez Alphonse Giroux et Cie. and was one of the most prestigious luxury stores in Paris.[11] The Giroux apparatus holds the distinction of being the first commercially produced camera, and each example bore a label displaying Daguerre’s signature and personal endorsement.[12]

Charles Chevalier built the first series of lenses for the Giroux camera. He was well-known as a prominent and highly successful third-generation Parisian optician who produced objectives for microscopes, binoculars, and telescopes. Daguerre’s relationship with the Chevalier family formed many years earlier. As early as 1824 Daguerre had become a regular customer of the firm, Vincent Chevalier aine, Pere et fils Ingenieurs-Opticiens Brevetes.[13] Although Charles’ father Vincent directed the firm at the time, both father and son had become well-acquainted with Daguerre, selling him lenses for his camera obscuras.[14] Daguerre had also shared with both Charles and Vincent, in late 1825, that he had successfully fixed a permanent image using a camera obscura.[15] Nicéphore Niépce, who had also been experimenting with methods to permanently record images, had become a customer of the Chevalier firm as well. Charles Chevalier informed Daguerre of Niépce’s work and suggested the two men meet, resulting in Niépce and Daguerre’s historic relationship, which began via written correspondence in January 1826. They met in person in 1827, and in December 1829 they executed a partnership agreement in order to perfect the process of permanently recording images.[16]

The lens Charles Chevalier provided for the Giroux camera was an achromatic, cemented doublet, which was a modified telescope objective. By combining lenses of different glasses and focal powers, achromatic lenses are corrected to bring two wavelengths (typically red and blue) into focus in the same plane, limiting the effects of chromatic and spherical aberration.[17]

Until 1841, two versions of this doublet lens were fitted to the Giroux cameras.[18] One version consisted of a biconcave lens of flint glass cemented to a biconvex lens of crown glass and was slightly meniscus in shape (figure 1). The other version of the lens featured a plano-concave lens cemented to a biconvex lens (figure 2). Although the earliest produced lenses featured a focal length of approximately 380 millimeters (fifteen inches) with an aperture of f/14, later versions differed slightly in focal length and thus featured a slightly smaller maximum aperture.^[19]

Figures 1 and 2. Diagram of lenses for the Giroux camera by Paul Chin, used under GNU free documentation license.

 

Limiting the lens’ aperture to f/14 helped suppress optical aberrations such as coma and spherical aberration, while allowing the lens to cover the full (whole) 164 x 216 millimeter plate size of the Giroux camera with respectable resolution. However, the small aperture coupled with the extremely low sensitivity of the silver-coated copper plate meant exposures typically took three to thirty minutes, depending on weather conditions.[20] As such, the daguerreotype process, as originally presented in 1839 with the Giroux camera and Chevalier lens, was most suitable for still-life and landscape views (leading Chevalier’s design to become known as the French Landscape lens). Taking portraits with this equipment was nearly impossible.

To make portraiture possible, opticians, chemists, and other men of science immediately set about reducing the exposure time the daguerreotype process required.[21] The commercial and artistic prospect of taking portraits motivated their timely response and experimentation, and they arrived at two primary solutions: faster lenses and increased sensitivity of the plates.[22]

In the spring of 1840, France’s Société d'Encouragements pour l'Industrie Nationale (Society for the Encouragement of National Industry), announced a competition “wishing to encourage useful improvements in the art of photography.”[23] Prizes in the form of cash and medals were offered to those, “who are bold enough to put to the test useful improvements to the art of photography.”[24] The deadline for the competition was set for the end of 1840.

Charles Chevalier immediately went about developing a lens for the contest. After some experimentation with his previous optical designs, he submitted a lens that featured two achromatic, cemented doublets spaced apart from each other, with a fixed aperture or “limiting stop” at the front of the lens(figure 3, top), resulting in a speed of f/10, which was modestly faster than his original f/14 landscape lens.[25] This design also reduced the focal length of the lens from about fifteen inches to eleven inches while still covering the whole-plate format. While the improvement from f/14 to f/10 was helpful, it still wasn’t fast enough for taking portraits, so Chevalier developed the design further by increasing the distance between the cemented doublets by creating an interchangeable component of the barrel and removing the stop altogether (figure 3, bottom).[26] These changes increased the speed of the lens to about f/5.2 and further shortened the focal length to facilitate portraits at closer range. The ability to convert the lens from a landscape to a portrait configuration and change focal lengths by simply replacing part of the barrel was a novel idea and represented photography’s first convertible lens. The dual-featured lens was named L'Objectif Double ou à Verres Combinés (double lens or combined glass) and was also known as Chevalier’s Photographe à Verres Combinés.^[27] Chevalier presented it to the Société d’Encouragements on December 1, 1840.[28] While the lens was certainly innovative, in its portrait configuration it suffered from significant field curvature and an overall lack of sharpness.^[29]

 

Figure 3. The landscape (top) and portrait configurations (bottom) for the L'Objectif Double ou à Verres Combinés as shown on page 81 in Chevalier’s book, Nouvelles instructions sur l'usage du daguerreotype, published in Paris in 1841.

 

In March of 1841—after the contest’s deadline had passed—the established Viennese optical firm of Voigtländer & Sohn submitted a portrait lens designed by Józeph (Joseph) Miksa Petzval to the Société.[30] Petzval (1807–1891) was a native of Hungary and a chaired professor of mathematics at the University of Vienna. At the request of his friend and colleague Andreas Ritter von Ettingshausen, Petzval focused his attention and mathematical abilities on designing a lens that could be used for portraiture.[31] Utilizing complex mathematical calculations and with the assistance of ten Austrian army members likewise skilled at mathematical computations, he designed a lens with an objective that could project a flat field with great speed. [32] Once the design was completed, Voigtländer—who furnished Petzval with the refracting and diverging indices of the lenses employed in the design—manufactured a prototype lens and mounted it to a makeshift camera in May 1840 (figure 4).[33] Anton Georg Martin, another faculty member at the University of Vienna with a great interest in daguerreotype processes, was involved in the testing of the lens and helping Voigtländer prepare it for commercial sale.[34]

Figure 4. The original Petzval lens and makeshift camera constructed by Voigtländer on display at the Vienna Technical Museum. Published on page 20 in Petzval József élete és érdemai, A Mathematikai és Physikai Társulat, by L. Erményi in 1906.

 

The reason for the late submission of the lens to the Société in March 1841 is unknown.[35] However, Voigtländer began selling the Petzval lens in November 1840 and also launched a daguerreotype camera (the Ganzmetallkamera) featuring the new lens on January 1, 1841. Therefore it is likely the firm was protecting its commercial interests for some period of time before submission to the French organization.^[36]

For more than a year, the Société debated the merits of the Petzval and Chevalier lenses and finally announced the awards for its contest on March 23, 1842. Chevalier received first prize, a platinum medal, and Voigtländer received second prize, a silver medal, for the Petzval designed lens.[37] The Société appears to have been heavily influenced by a sense of nationalism in the judging, but the Société defended its position, stating the Chevalier lens, with its convertible features and ability to cover the whole-plate format was a more significant achievement than the Petzval lens, which originally could only cover the much smaller quarter-plate format.[38] It also didn’t hurt Chevalier’s chances that he was a board member of the Société.[39] Ultimately history and the marketplace would prove the Société’s decision a bit misguided.

Petzval’s design provided fine sharpness in the center of the image, excellent correction of spherical aberrations and coma, and featured a very large aperture of f/3.6.[40] The design was significantly faster than the original Chevalier landscape lens and more than twice as fast as Chevalier’s newer portrait design, in addition to providing far better resolution. The Petzval lens was also the first objective to use specific mathematical computations in its design, as opposed to the previous method of trial and error. [41] The lens’ primary limitation—due to fairly significant field curvature—was its narrow useable field of view, which measured about twenty four degrees.[42] However, this drawback did not hinder its use in portraiture, as it tended to provide a subtle vignette to portraits and helped focus the viewer’s attention on the central portion of the plate, which typically featured the subject’s head and shoulders.[43] The lens was nearly perfect for portraiture and literally gave birth to commercial photography by enabling daguerreotype portraits to be made for a relatively low cost.

Figure 5. Portrait of Joseph Petzval. Lithograph by Adolf Dauthage, 1854.

 

Optical Design

 

Thomas Sutton described the Petzval lens in his 1858 book, A Dictionary of Photography as follows:[44]

 

Petzval’s Portrait Combination. The object of this instrument is to obtain an image well defined in its principal parts, when a large volume of light is admitted. In taking a portrait it is evident that the time of exposure should be reduced as much as possible, because after remaining in a constrained position for a long time the features of the sitter betray an expression of the discomfort felt. A lens of large aperture must therefore be employed in portraiture, so long as photographic processes remain in their present state of insensitiveness (sic).

 

The front lens [A] is a compound lens, exactly like the common view-lens, but placed with its convex side to the objects. It is achromatic, but not entirely aplanatic; this defect being remedied by the posterior lens (figure 6).

 

The posterior lens is composed of two lenses [B & C] separated by a small space; that next the front lens is of flint glass, convex-concave, and divergent, being thinner in the middle than at the edges; the other is biconvex, and of crown glass, being placed with its most convex side next to the concavity of the flint…The posterior compound lens is achromatic, and the object of separating the lenses and giving them curves so different from that of the front lens is to cure spherical aberration in the entire combination.

 

Figure 6. Petzval lens illustration from page 152 of Optics: Light and Sight by E. Nugent, published in 1870.

 

 

In more modern language, the Petzval design features two fairly thin achromats spaced well apart. The front component of cemented elements (crown element on the exterior, flint element on the interior) was derived from an ordinary telescope doublet.[45] In addition to the rear component featuring an air space, the rear elements (flint on the interior, crown on the exterior) also differ in curvatures from the front elements. The air space and curvature differences serve to correct for spherical aberration and coma.[46] However, residual uncorrected aberrations can cause poor peripheral resolution, so in order to obtain satisfactory sharpness over most of the field of view, a longer focal length than normal is required to cover a given format.[47]

 

Figures 7 and 8. Cut-away of a half plate sized Petzval lens. Image by Alex Timmermans, a Netherlands-based artist specializing in collodion-based photography, used with permission.

The Petzval design—with its rapid speed and fine optical performance in the center of the image—became an instant success because it helped resolve the daguerreotype process’ initial inability to capture portraits. And, due to a lack of global patent protection (it only held an Austrian patent), the design was quickly copied the world over. In fact, lenses featuring the Petzval design would be referred to and advertised around the world under many different names during the 1840s and 1850s, including the following:

 

It is important to note that when a lens is referred to as a “Petzval,” it does not denote the maker of the lens nor any precise specification. The name Petzval only refers to a type of portrait lens that features the general optical layout that Joseph Petzval invented. While Petzval lens makers followed this optical design, there could be minor variations in glass, element curvatures, element thicknesses, lens speed, and construction details from one maker to the next. Metaphorically, the Petzval design was the recipe, but lens makers decided the final amount of each ingredient as they constructed their own lenses.

Petzval lenses also “evolved to become the standard projection lens for nineteenth-century magic lanterns.”[48] “The Petzval lens was found to be very useful in the magic lantern, the large aperture and narrow field being suited to the long throw and bright images on the screen.”[49] So useful was this design for projection purposes that, “modified forms of the Petzval lens are still used [as of 1978], mainly for the projection of 16 and 8-millimeter films and other projection devices.”[50]

Optical Signature

The optical signature of the Petzval lens typically features fine central sharpness over a very narrow field, with significant curvature of field and progressive vignetting. As previously mentioned, these design “defects” benefitted portraits, as the vignetting and reduced definition away from the image’s center helped focus the viewer’s attention on the well-defined central portion of the plate, which typically featured the subject’s head and shoulders. Essentially, the lens created a subtle halo effect around the subject. Figure 9 displays the design’s prominent curvature of field and demonstrates how light rays travel through the Petzval-designed lens.

Figure 9. An illustration of the Petzval’s curvature and refraction of light, from page 65 of Handbook of the Practice and Art of Photography by Hermann Wilhelm Vogel, published by Benerman & Wilson Publishers of Philadelphia in 1871.

 

 

Figure 10. Image taken with a Hermagis 360-millimeter Petzval lens at full aperture (f/4.5) of Redmond O'Hanlon. Photo by Alex Timmermans, used with permission.

Petzval Lens makers

 

Because of Voigtländer’s involvement in the creation of the first Petzval lenses as well as their high-quality manufacturing, the industry considered Voigtländer lenses to be the standard by which other portrait lenses were judged. The firm maintained its reputation for superior Petzval lenses throughout the nineteenth century. In an 1851 article advising what photographic equipment to purchase, author and daguerreian artist J.H. Fitzgibbon wrote, “Voigtländer and Sons of Vienna have attained the greatest celebrity in the daguerreian world for the perfection of their instruments, and well do they deserve their fame, for their lenses are the finest at present known.”[51] In an 1867 report from the Paris Universal Exhibition, the writer remarked, “more than a recognition of the generally acknowledged excellence of the lenses by Voigtländer will scarcely be deemed needful.”[52]

 

Figure 11. Voigtländer whole plate lens, serial number 611, circa 1842. Photo by Dan Colucci.

 

Voigtländer’s quality lenses came at a cost and were typically the highest priced lenses in the marketplace. Their lenses commonly sold for more than double their competitors’ offerings. An 1864 catalog published by Bland & Company of London listed the following prices in British pounds for whole-plate sized Petzval lenses from various makers: Voigtländer, fourteen pounds; Lerebours, nine pounds; Jamin, seven pounds; and five pounds for a generic lens.[53]

Despite Voigtländer’s reputation and initial market leadership in the 1840s, competition developed fairly rapidly, primarily in France. Noël Paymal Lerebours of Paris was, like Chevalier, a distinguished and well-established optician who became involved in producing landscape lenses for the Giroux daguerreotype camera when demand exceeded Chevalier’s initial production.[54] Lerebours embraced the Petzval design and was producing his own Petzval lenses by the early 1840s.[55] Many other opticians, seldom mentioned or virtually unknown today, were also making Petzval lenses in France, Germany, England, and other European locations by the mid-1840s; however, these were produced in relatively small quantities.[56] Even Chevalier—who originally felt Petzval plagiarized his designs and didn’t want to admit Petzval’s design was superior to his own portrait lens—would go on to manufacture Petzval lenses by the 1850s.[57]

In the United States in the mid-1840s, opticians such as John Roach of New York City and Henry Fitz, Jr. of New York City and Baltimore produced Petzval lenses, but only on a small scale.[58] A significant number of unmarked lenses of French origin were imported to the United States and regularly competed with domestic lenses.[59] In fact, it was common to find imported Petzval lenses fitted to American-made cameras during the daguerreian period.[60] However, in 1849, after studying lens making under Fitz, daguerreian artist, Charles C. Harrison of New York City rose to prominence and became the first American optician focused entirely on the production of photographic objectives.[61] In 1851 Harrison’s Petzval lenses gained international recognition after receiving medals at the annual fair held by the American Institute of the City of New York and at the Great Exhibition (World’s Fair) in London.[62] Harrison’s lenses were considered excellent performers, and they challenged Voigtländer’s reputation for the finest portrait lenses throughout the 1850s and early 1860s.[63] In London the well-established optical firm of Ross & Company produced highly-regarded Petzval lenses by the early 1850s. John Henry Dallmeyer, who had worked for Ross & Company, established his own firm in 1859 and would become England’s highest-regarded lens maker producing quality Petzval portrait lenses.[64]

Other notable makers of Petzval lenses during the nineteenth century include Busch, Steinheil, and Kranz of Germany; Waibl and Dietzler of Austria; Jamin, Darlot, Derogy, and Hermagis of France; Horne & Thornthwaite and Wray of England; Grubb of Ireland; Suter of Switzerland; Chapman, Lewis of the United States; and Holmes, Booth & Haydens of the United States.

While production numbers from most lens makers are difficult to establish, we have some information for a few of them. Based upon known serial numbers of Harrison lenses and the following passage from Marcus A. Root’s book, The Camera and the Pencil, “up to May 15th, 1863, he had constructed eight thousand eight hundred and seventeen of the lenses in general use,” we can estimate Harrison produced approximately 9,500 Petzval lenses from about 1849 until his death in November 1864.[65] Holmes, Booth & Haydens appears to have sold just shy of 11,000 Petzvals from the mid-1850s until the late 1860s.[66] Voigtländer, as a point of comparison, appears to have produced approximately 25,000 Petzval lenses for cameras from 1840 until about 1920.[67]

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Today, Petzval lenses are in great demand in the marketplace. Not only have collectors found a new appreciation for nineteenth-century lenses, but photographers practicing wet-plate photography and other alternative processes have come to prize the optical abilities and effects of the design. Photographers making images with Petzval lenses tend to use them at very close range, which only emphasizes the lens’ minimal depth of field, field curvature, and out-of-focus characteristics (also known as bokeh), which can create arresting imagery. Additionally, many users further exaggerate the design’s optical flaws by using Petzval lenses with too little coverage for the format size employed, producing images that display a very interesting swirled background to beautiful effect. These “Petzval Swirlies,” as they are known, appear to be caused by off-axis uncorrected coma and spherical aberration.[68]

This renewed interest in Petzvals, from both collectors and users, has created high demand for these lenses over the past number of years. Up until about a decade ago, most nineteenth-century Petzval lenses could be purchased for seventy-five to two hundred dollars depending on size, speed, and brand. Collectors and users had neglected these lenses as antiquated relics. However, over the past ten years or so, perhaps as a backlash to the rise of digital photography, more photographers have become interested in practicing older photographic methods such as collodion-based (wet-plate) image making, and they are using period equipment to do so. At the same time, collectors who previously focused most of their collecting efforts on cameras have also turned their attention to collecting nineteenth-century lenses.

These two factors have created new demand for antique lenses in general and sent prices for Petzval lenses, in particular, skyrocketing. Even “no-name” cheaply constructed Petzval lenses can now command hundreds of dollars. Well-known, high quality lenses, such as those by made by Voigtlander, Dallmeyer, and Harrison can regularly sell in the range of one to three thousand dollars, depending on their size and specifications (the larger the lens, the higher the price, generally). Petzval lenses that can cover ultra-large formats (greater than fourteen inches), can easily fetch five to ten thousand dollars, given their rarity. In general, you’ll find that most prices for Petzvals have doubled and tripled over the past decade.

Interestingly, Lomography Shop, an online retailer, has very recently decided to capitalize on this high interest in Petzval lenses, and on July 25, 2013 launched a Kickstarter campaign to raise funds to produce a modern day Petzval lens for use with all Nikon F and Canon EF mount analog and digital SLR cameras. The lens will feature a maximum aperture of f/2.2 and has a starting price of four hundred ninety-nine dollars.[69] It will be produced by the Zenit factory in Krasnogorsk, Russia.[70] Within a period of just thirty days, the campaign raised just under 1.4 million dollars, ensuring the project will move forward.[71] The company writes the following about the lens: “You’ll get an area which is very sharp at the focus of the photograph over a narrow field. There is then progressive vignetting towards the non-focused areas; this helps draw the viewer’s attention to the crisp and focused area of the photograph.”

They go on to write, “It's because of the early large aperture optic design of Petzval that photos taken with the lens will have this beautiful, swirly bokeh effect in the background. These quirky, creative and unique effects from the lens have endeared it to a whole new generation of photographers. Using the Petzval lens is totally different to just adding a filter to your shots in post-production; it’s about achieving a real optical effect caused by the lens attached to your camera.”[72]

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Size and Speed

Petzval lenses were produced and marketed according to the plate size or format they covered. Up until the late-1840s, Petzvals were typically sold in the following sizes: quarter plate or 1/4 plate (3¼ x 4¼ inches); half plate or 1/2 plate (4¼ x 5½ inches); and whole plate or 4/4 plate (6½ x 8½ inches).[73]

By the close of the 1840s, manufacturers began making larger lenses to cover daguerreotype plates in excess of the whole-plate size. As daguerreian artists perfected their art and competition escalated, there was a small but meaningful demand for larger lenses to cover larger plate sizes. Although they were very expensive, the ability to make larger daguerreotypes helped distinguish a photographer’s abilities and created a distinct marketing advantage. However there was far less standardization to the actual dimensions of these larger plate sizes, and international dimensions could vary widely. The two most common larger plate sizes were typically referred to in the United States as: double whole plate or 8/4 plate and mammoth plate or 12/4 plate.[74] These daguerreotype plates typically ranged in size from about 10½ x 13½ inches to 14 x 17 inches.[75] By 1853, both Voigtländer and Harrison were manufacturing lenses with glass diameters in excess of 6½ inches to cover these larger plate sizes.[76] The Anthony Company’s 1854 catalog lists Harrison lenses in sizes from quarter (1/4) plate through mammoth (12/4) plate available for sale. [77]

Creating even greater demand for bigger Petzval lenses was the rise of collodion-based wet-plate photography in the late 1850s and 1860s. Glass plates used for this process were far less expensive than daguerreotype plates, so larger format sizes were utilized, which created the need for even larger Petzval lenses.[78] By 1864, Voigtländer described its No. 13 Petzval lens as having a focal length of thirty-five inches (900 millimeters) and the ability to cover twenty-four inch plates.[79]

Because Petzval lenses cover sizeable plate areas, feature large relative apertures, and have a long-focus design, the laws of physics require them to be physically large objects. Combining the weight of brass barrels and the sizeable chunks of glass required to make them, Petzval lenses also tend to be quite heavy. For example, a whole-plate size lens Voigtländer Petzval from the early 1840s weighs more than three pounds, stands more than eight inches tall, and has a 3½-inch barrel. Lenses produced to cover larger plates were exponentially larger and heavier. The mammoth-plate size lens made by Holmes, Booth, & Haydens is twenty-two inches tall, weighs twenty-three pounds, and features a six-inch diameter front lens and seven-inch diameter rear lens (figure 12).

 

Figure 12. Petzval lenses of various sizes. Front, left to right: Voigtländer whole plate (4/4) size, circa 1842; John Roach half plate (1/2) size, circa 1850; C.C. Harrison quarter plate (1/4) size, circa 1853. Rear: Holmes, Booth & Haydens mammoth (12/4) size, circa 1860. 7 ½-inch pencil shown for scale. Photo by Dan Colucci.

Initially, most Petzval lenses were produced with a maximum aperture of f/4, plus or minus a half stop; however, beginning about 1850 some makers began to offer Petzval lenses of different maximum apertures (speeds) within a given format size. Larger manufacturers typically offered two different speeds in the more common format sizes. Although each vendor had its own marketing terms to describe its lenses, the most common Petzval featuring an aperture of around f/4 was typically advertised as a “portrait lens” although adjectives such as “quick,” “rapid, ”or “standard speed” were also used to describe these lenses.

An upgrade to the standard-speed Petzval lens was a faster version, typically featuring an aperture in the range of f/3 to f/3.5. These lenses were commonly called “extra-quick,” “fast worker,” “superior,” or a “first-quality” lens. These lenses were, correspondingly, much more expensive, based on the additional manufacturing expertise involved in grinding and mounting larger glass elements coupled with the increase in raw materials needed to produce these bigger and heavier lenses. Depending on the brand, these faster lenses were typically fifty to one hundred percent more expensive than the standard-speed Petzvals. For example, in 1876, Dallmeyer’s Patent Portrait 3A “Ordinary Intensity” lens for whole plates featuring an aperture of f/4 sold for twenty-seven British pounds, while the 4B “Quick Acting” whole plate lens with an f/3 aperture cost forty pounds.[80]

A third speed of Petzval emerged from Dallmeyer. This model was referred to as a “Portrait and Group” lens and had an aperture of f/6.[81] The smaller aperture provided increased depth of field, greater plate coverage, and more uniform sharpness across the field, which allowed users to photograph groups of people and keep them all in focus with acceptable sharpness. These lenses were physically smaller, given their reduced maximum aperture, and much more affordable. Dallmeyer’s Patent Portrait 3D Group lens for whole plates cost a mere nine pounds in 1876.[82]

Aperture Control

Through the 1840s and until the mid-1850s, certain makes of Petzval lenses were sold with metal, washer-style stops to reduce the aperture of the lens. These were typically inserted or screwed in front of the lens or, less commonly, inserted inside the middle of the barrel between the lens groups by taking the lens apart.[83] Photographers would also sometimes fashion their own stops out of blackened paper or cardboard and insert them in a similar fashion as the manufactured metal stops. However, during the early part of this period most Petzval lenses were used at maximum aperture to keep portrait sitting times to an absolute minimum, so there wasn’t a significant need for sophisticated aperture control. But by the mid-1850s increases in the sensitivity of materials, the advent of collodion-based photography, and an increase in outdoor photography created a need for greater aperture control. By 1856 a few individuals designed ways of inserting aperture stops into the barrel from the exterior of the lens, a far more convenient solution than removing the front section of the lens to insert a stop. ^[84] John Waterhouse of Halifax, England, is commonly credited with inventing a method of inserting stops through the mid-section of the lens barrel, hence the name “Waterhouse stop.”[85] These were also referred to generically as “central stops” or “diaphragms.”[86] Waterhouse wrote and published a detailed and fully illustrated explanation of these stops in the July 21, 1858 issue of The Journal of the Photographic Society of London.[87] While the invention date of Waterhouse stops is commonly cited as 1858, a letter to the editor of The Journal of the Photographic Society of London, written by Joseph B. Reade and dated March 18, 1859, mentions Waterhouse describing his method of using diaphragms as early as the winter of 1856.[88]

Figure 13. Dallmeyer 3B Patent Portrait lens with matching set of Waterhouse stops. Photo by Alex Timmermans, used with permission.

 

By 1860, most makers were offering their Petzval lenses with optional Waterhouse stops.[89] Since these stops only needed a thin slot cut in the lens barrel to perform their function, photographers commonly performed minor surgery on their older lenses to add this option.[90] Historically, this means many Petzval lenses from the 1840–1855 period are found with their barrels cut post-manufacture. This practice makes finding unaltered lenses from this period far more challenging for collectors.

Another important aperture control device was created at this time by Charles C. Harrison and Joseph Schnitzer. In 1857 they applied for a patent for a novel type of iris diaphragm. Their patent was approved on September 9, 1858 (United States Patent 21,470). It is unknown how and when the iris diaphragm was originally invented, but Harrison and Schnitzer’s version featured a construction that became the basis for iris shutters in the 1880s as well as for automatic aperture control in many modern-day cameras.[91] An iris diaphragm allows the aperture size to be easily manipulated from the exterior of the barrel, and it allows for a full range of adjustable aperture sizes within the lens’ entire opening. The Harrison and Schnitzer diaphragm was not only a significant feature on Harrison’s 1857 Orthoscope lens but was also fitted to some of Harrison’s Petzval lenses, making it the first example of an iris diaphragm built into a Petzval lens.

Figures 14 and 15. Harrison Orthoscope Lens featuring the patented diaphragm, circa 1857. Photo by Dan Colucci.

Because the iris diaphragm was simple to manipulate, eliminated the need to carry multiple metal stops around, and provided infinite adjustment within the lens’ aperture range, it would eventually become the standard aperture control for most photographic lenses in the twentieth century. However, because Waterhouse stops were effective, simple to manufacture, and much less expensive—especially for larger Petzval lenses—they would remain the primary aperture control device for these lenses from the late 1850s through World War I. Still, a few lens makers in Europe and the United States did produce Petzval lenses with the option of the more expensive iris diaphragm with some regularity beginning in the 1890s.[92]

Construction

A Petzval lens typically features one of two types of barrel construction. The first type features a fixed-length barrel with no focusing adjustment, usually reserved for the largest Petzval lenses because any type of focus adjustment would have been impractical and costly due the sheer weight and size of the lens. The second and more common type of construction features an outer sleeve with a gear-driven focusing mechanism that moves the entire inner barrel, allowing for very fine focusing adjustments when the lens is mounted to the camera. Lenses of this construction have either a tangent or a radial drive mechanism to move the inner barrel. Apparently, these terms have originated from lens collectors: the radial drive is named for being in line with the radius of the lens, while the tangent drive is named for its location tangent to the lens barrel. ^[93]

The tangent drive was built into the very first portrait lenses produced by Voigtländer and other European makers and was derived from the construction of other optical instruments, such as the microscope. Tangent drives were prevalent on American-made lenses of the 1840s, but starting around 1850, radial drives became common on American lenses.[94] While there are exceptions to this rule, a tangent drive typically indicates a lens of European origin, and a radial drive indicates American origin.[95] The radial drive petered out in American lenses during the 1880s—most likely due to the higher manufacturing cost of its internal construction—while the tangent drive continued to be used on Petzval lenses until the lens fell out of fashion later in the twentieth century.

Figures 16 and 17. Tangent drive from Voigtländer lens, circa 1842; Radial drive from Holmes, Booth & Haydens lens, circa 1855. Photos by Dan Colucci.

Petzval Variations

Although the original Petzval design endured for about a century, there are a few variations worth noting. Jean Theodor Jamin patented the first minor variation on March 7, 1855.[96] The lens was named the Objectif Double à Cône Centralisateur (Double lens with Centralizing Cone) and has three modifications on the original design. First, the lens uses a very distinct cone-shaped rear barrel component. The conical shape helps eliminate internal reflections inside the lens, which in turn reduces flare and improves contrast. Second, the lens was made so the front objective could be removed, reversed, and used to replace the rear group, which converts it from a portrait to a landscape lens.[97] Third, the lens allows for adjustments to the distance between the front and rear group of elements to correct for optical aberrations at any object distance.[98] In essence, this lens adopted the Chevalier idea of a convertible lens while maintaining the Petzval optical design. Jamin and his successor Alphonse Darlot sold many of these lenses in various sizes for at least a decade.[99]

Figure 18. Cône Centralisateur lenses, versions by Jamin and Darlot. Photo by Alex Timmermans, used with permission.

 

The next variation appeared in 1860, when John Henry Dallmeyer updated Petzval's design to create his Quick-Acting Portrait Lens, advertised as having improved correction of spherical aberrations and an aperture of f/4.[100] These lenses were “especially constructed for Carte-de-Visite Portraits.”[101] Dallmeyer further developed the Petzval design in 1860 by modifying the rear element curvatures to feature a very large aperture of f/2.2, creating his Extra Quick-Acting Portrait Lens.[102] These lenses were advertised as “possessing the greatest possible rapidity consistent with perfect definition,” and “especially constructed for Portraits of Children, but generally useful also for Vignettes, Cartes-de- Visite, Locket Portraits, &c.”[103] While they could only cover small formats (4 x 5 inches and smaller), these lenses were one of the fastest regularly produced Petzval lenses on the market from 1860 until 1904, until Bausch & Lomb created an f/2.2 Petzval lens of very similar design for larger formats.[104] In 1866, Dallmeyer designed the most significant variation of the original Petzval design, his highly successful Patent Portrait Lens. [105] He offered this model in three different maximum apertures: f/3, f/4 and f/6.[106] The design flipped the rear lens group of the original Petzval and modified the curves of the rear elements (figure 19).

Figure 19. Top, Dallmeyer’s Patent Portrait Lens design. Bottom, Petzval’s original design. Illustrations from United States Patent 65,279.

 

In marketing the Patent Portrait Lens, Dallmeyer claimed his modifications provided numerous benefits over Petzval's original design, including improved sharpness as well as reduced flare, distortion, and vignetting. Additionally, Dallmeyer’s lens allowed the user to adjust the rear element group by unscrewing the rear cell, which would introduce spherical aberration to the image and create an effect he called “diffusion of focus.” According to Dallmeyer photographers could add varying degrees of diffusion to their images to create, “any desired amount of diffusion of focus, or distribution of definition” without having to sacrifice lens speed.[107] Dallmeyer went on to explain that diffusion of focus had the effect of “sacrificing extreme sharpness of image on one plane” so that “objects situated at different distances from the lens, within certain limits, will all appear in moderately good focus.”[108]

Dallmeyer's diffusion of focus claim created some controversy in the optical and photographic communities as many believed it to be an erroneous claim that defied the laws of optics. The following account is from the London-based periodical, The Photographic News, published on May 2, 1884:

In the year 1866, the late Mr. J. H. Dallmeyer patented a variation of the Petzval lens. This variation consisted in reversing the elements of the back combination with such a modification of the curves as this change involves. The particular advantage claimed at the time for this form of lens has since been abandoned. The putting of the negative lens at the back allowed its distance from the positive element to be varied, and thus the perfection of its correction for spherical aberration to be modified. It was stated that by altering the distance of the back lens, so as to re-introduce spherical aberration, and sacrifice definition at the focus, improved definition was obtained upon the planes not in focus. This claim—“diffusion of focus” it was called—was shown to be mistaken, and is no longer made. The lens, however, when employed with the element in the position of best definition, is a useful one. Other well-known opticians have for some time past issued a series of lenses of this form. In this case, however, the back lenses are burnished together into their cell, and no shifting or alteration of their position is possible.[109]

The point being argued or at least clarified here was that introducing spherical aberration does not improve nor distribute focus on other planes. A book on photographic lenses, authored in 1901, explained, “It is a common error to suppose that depth is increased by the presence of aberration; the exact contrary is the case. The mistake is due to the fact that if the lens will not produce perfect definition under any conditions, we naturally make allowance for a circle of confusion that is much larger than 1/100 in….The lack of a critically sharp standard of definition aids to produce an appearance of great depth that is very deceptive in a small image. Enlargement will prove that this pseudo-depth is only universal bad definition.”[110] The same book added in a later chapter, “The portrait lens at a large aperture has a very small angle of definition and little depth. Extreme sharpness is therefore confined to the center of the plate and to one plane of the object, and this effect is sometimes objectionable. The introduction of spherical aberration destroys this extreme local sharpness and renders the definition more uniform and the depth apparently, but not really, greater.”[111]

It appears Dallmeyer ended up dealing with this issue in his advertisements by writing that his lens could create “the impression of a general distribution or depth of focus; and this is in proportion to the amount of unscrewing.”[112] Despite this issue, Patent Portrait lenses sold quite well and were advertised over a period of approximately seventy-five years.[113] Ultimately, the lenses were popular because of their versatility and superb craftsmanship. With this one lens, photographers could create images with the same excellent definition as any other Petzval, or they could introduce varying degrees of spherical aberration to lessen resolution and, “so obtain a more artistic and pleasing result.”[114]

By allowing for the purposeful reduction of resolution, the Patent Portrait lens is also photography’s first soft-focus lens.[115] Russell Young, a doctoral candidate at the University of St. Andrews, wrote in his dissertation, “The basic principle of a shifting lens element of an otherwise well-corrected lens was still in use in the 1980s, and if newer soft focus lenses are ever put into production again, the principle remains at the foundation of soft focus [lens] design.”[116]

Figure 20. Advertisement for Dallmeyer’s Patent Portrait Lenses published in The Lens: A Practical Guide to the Choice, Use, and Testing of Photographic Objectives, by Thomas Bolas and George Edward Brown, published by Dawbarn and Ward , Ltd. of London in 1902.

During the 1870s and 1880s, the Voigtländer firm designed additional Petzval variants and, interestingly, they flipped the order of the rear elements creating a construction very similar to Dallmeyer’s Patent Portrait lens. Hans Zincke-Sommer, stepson of Friedrich Voigtländer and the company’s chief lens designer at the time, proposed the first modified design in 1870. This new design featured an impressive maximum aperture of f/2.37.^[117] However, the design would not be manufactured until about 1888, for unknown reasons. Ultimately, the lens would be sold as Voigtländer’s Series Ia Portrait lens with an aperture of f/2.3 (figure 21). A Voigtländer catalogue from around 1910 described the lens as having “four lenses, of which two are cemented together. The angle of the picture proper is 22 degrees; the structure is very elongated, so that vignetting soon takes place. In spite of the small field excellent results can be obtained in small sizes.” It went on to state that the lens is “specially adapted for cinematograph exposures, and for studio work in very weak light, but not for landscape photography or general pictures.”[118] Given its specialized use and how scarce this lens appears to be in the current marketplace, it doesn’t appear to have sold well.

Figure 21. Advertisement for Voigtländer’s Series Ia Portrait Lens as it appeared on page 60 of the Voigtländer & Sohn Photographic Lenses and Cameras and Accessories Catalogue, circa 1910.

 

 

In 1878, Friedrich von Voigtländer made more dramatic modifications and “found that by suitably bending the front component of the Dallmeyer type he could cement the rear component also, and it is this last arrangement that is used today [1978] as a small projection lens of high aperture.” [119] There is no evidence that this design was ever used for photographic imaging, however a considerably modified version was commonly used in movie projection for many years.[120]

Figure 22. 1878 Voigtländer modified Petzval optical layout. Illustration published on page 276 of Theorie und Geschichte des photographischen Objektivs by M. Von Rohr in 1899.

Further tweaking of the rear element curvatures by Voigtländer would result in their 1885 production of the Quick-Worker Series I Petzval lens which featured an aperture of f/3.16 (figure 23).[121] Despite this model being a highly capable performer, Petzval portrait lenses had basically run their course by this time, as more alternative lens types and more sensitive, faster plates became available, which reduced the need for such rapid lenses.

Figure 23. Advertisement for Voigtländer’s Series I Portrait Lens as it appeared on page 60 of the Voigtländer & Sohn Photographic Lenses and Cameras and Accessories Catalogue, circa 1910.

 

 

In fact, by the mid-1880s, Voigtländer, who built its photographic reputation on Petzval lenses, began to move away from the Petzval design for portrait work as the firm focused sales efforts on its Euryscope line of lenses, first brought to market in 1877 as a general-use lens.[122] Similar to the extremely popular and historically important Rapid Rectilinear and Aplanat lenses patented in 1866 by Dallmeyer and Steinheil, Euryscope lenses featured, “two perfectly symmetrical and cemented combinations.”[123] The Euryscope’s symmetrical design, like the Rapid Rectilinear and Aplanat designs, produced a lens that was virtually distortion-free. It also provided good plate coverage and maintained fairly large maximum apertures, typically f/6 to f/8.[124] Voigtländer further developed this lens type and in 1886 created a portrait version of this design with an aperture of f/4.[125] By 1890, a catalogue featuring Voigtländer lenses, described two versions of this lens, the Second Series Portrait-Euryscope with an aperture of f/4, and the Third Series Portrait-Euryscope, featuring an aperture of f/4.5.[126] The catalog (figure 24) stated, “these new Portrait-Euryscopes produce more brilliant pictures and improved definition, with absolute freedom from distortion.”[127] It went on to state, “Voigtländer’s new Portrait-Euryscope marks the first great and important improvement in Portrait-Objectives since the introduction, in 1840, of the Portrait-Combination with separated back-lenses, which is in use up to the present day.”[128] This description indicates Voigtländer’s concession that the Petzval was no longer the first choice in portrait lenses.

 

Figure 24. 1890 Advertisement for Voigtländer’s Portrait-Euryscope Lens from the Illustrated Catalogue of the Celebrated Voigtländer & Sons Portrait-Lenses and Euryscopes published by Benjamin French & Co. in April 1890.

The Long Goodbye

The most significant development that precipitated the decline of the Petzval was the invention and use of higher refractive index glasses, such as barium crown, as early as 1886.[129] Ernst Abbe and Otto Schott, founders of Schott Glassworks in Jena, Germany, invented and developed numerous types of new glass possessing improved optical qualities, which opened up fresh lens design possibilities.[130] Prior to this development, lens designers had only two types of optical glass available to them, crown and flint.[131] Although formulas differed in the nineteenth century, crown glass was typically made with oxides of lime and sodium and featured relatively low refractive indices (how fast light passes through the glass) and low dispersion (the separation of visible light into its different colors).[132] Flint glass, commonly made with lead oxides and potassium carbonate (potash), had a relatively high refractive index and high dispersion.[133] Only having these two glass types available prior to the mid-1880s limited the creativity of previous lens designs, including the Petzval lens. While these previous designs were fairly well-optimized within these limitations, the optical properties of crown and flint glass never allowed lenses to be completely free of astigmatism. Astigmatism, or the inability to project horizontal lines into the same image plane as vertical lines, results in an overall reduction of image resolution. Not only could these new glass types reduce or eliminate astigmatism, they were well-corrected for chromatic and spherical aberration and could produce extremely flat fields of focus.[134]

In 1888, using the newly invented barium crown and flint glass, Dr. Hugo Schroeder, lens designer and director for Ross & Co. of London, patented a wide-angle lens design that was nearly free of astigmatism.[135] This design would be manufactured and sold as the Concentric lens. While it was a milestone in lens development, the design needed a small aperture of f/16 to compensate for and minimize the lens’ uncorrected spherical aberration.[136] In 1890, Paul Rudolph, working for Carl Zeiss Optical Works, also in Jena, Germany, created a lens essentially free of astigmatism with the brand name Anastigmat (renamed Protar in 1900).[137] Rudolph’s design—which also used the new barium crown glass—was significant because Zeiss was able to produce numerous lens types from it: extreme wide angle, wide angle, general use, and a portrait type that featured an aperture of f/4.5. Anastigmat lenses were extremely popular, and Zeiss claimed that over 100,000 were sold by 1900.[138] By using these new glass types and virtually eliminating astigmatism, the Concentric and Anastigmat lenses ushered in the age of modern lens design.[139]

Whereas the Petzval lens had reigned supreme for portrait work, new designs with new glass arriving on the market featured better aberration correction, improved resolution, and less vignetting, as well as reduced size and weight. As such, the demand for Petzvals declined at an accelerating pace as the nineteenth century ended. In addition, advances in artificial lighting and greatly improved sensitivity of plates and film would lessen the need for lenses of such high speed, which had been one of the Petzval’s most significant advantages.

Notable competition for the Petzval arrived in August of 1897 with Zeiss’ Planar lens, designed in 1896 by Paul Rudolph (German Patent 92,313).[140] The Planar was a further development of the Anastigmat lens using a symmetrical layout of six elements. The Planar featured rapid apertures in the range of f/3.6 to f/5 in a wide range of format sizes with terrific resolution and flatness of field.

In 1898, another Petzval alternative reached the market, the Cooke Series II Portrait lens, produced by Taylor, Taylor & Hobson. This lens was based upon the landmark Cooke triplet design of 1893 and featured a diffusion device similar to the Dallmeyer Patent Portrait lenses.[141] This highly successful lens was sold in various incarnations for the next fifty years.

The next prominent Petzval alternative was Voigtländer’s own Heliar lens, first patented in 1900.[142] Voigtländer positioned the Heliar as the premier professional portrait lens on the market, and it sold quite well in the years following its introduction.[143] The Heliar became so popular that it remained on the market through the 1960s as a highly regarded and very capable optic.[144]

In 1902 Zeiss brought the Tessar lens (also designed by Paul Rudolph) to market as an f/6.3 general-use lens.[145] Brisk sales prompted tweaking of the Tessar to feature faster apertures, including an f/3.5 version introduced in 1907 that captured some of the portrait lens market.[146] The following years would present more and more choices for portrait lenses, and no single design dominated the market as the Petzval had in the nineteenth century.

While the Petzval remained the “old standby” for many portrait studios well into the twentieth century, new sales of Petzval lenses declined dramatically by the start of World War I. The Petzval was relegated to just a page or two in most photographic supply catalogs. Although Petzvals continued to be sold, at this point they were specialty items, and most models featured a diffusion mechanism to capture photographers’ increased interest in soft-focus imagery in the 1920s and 30s. Although a photographer could still purchase Dallmeyer’s Patent Portrait Lens with its diffusion capabilities as late as World War II, sales were extremely limited by this time.[147]

Rather than abruptly ending, the demand for Petzval lenses had a rather soft landing, which befitted a lens that was once the singular choice for portrait work for almost fifty years and ultimately remained on the market for nearly a century. Its endurance during a period of continuous innovation and experimentation, particularly in photographic circles, is a remarkable testament to Joseph Petzval’s design. Rudolph Kingslake, eminent lens designer and the head of Kodak’s Optical Design department for more than thirty years, wrote in 1953, “Petzval’s Portrait lens was one of the most successful lenses ever to be designed.”[148]