Petzval with diaphram

[Peter K]

As I understand it the aperture diaphragm appeared sometime around 1900?

The iris diaphragm itself is much older. But Nicéphore Niepce (1765 - 1833) has used an iris diaphragm in one of his cameras made 1816, as shown at the Musée Denon in Chalon-sur-Saône, France. Also the iris diaphragm was buildt in the lenses made by Ch. Chevalier in 1840 for cameras used by Louis Mandé Daguerre (1787 - 1851).

[Ernest B.]

"The iris diaphragm itself is much older...Also the iris diaphragm was buildt in the lenses made by Ch. Chevalier in 1840 for cameras used by Louis Mandé Daguerre (1787 - 1851)."

Peter,

That's interesting. I didn't realize the further background. Was the legitimacy of the award of the U.S. patent to Harrison and Schnitzer contested?

A quick, followup Google search seems to indicate that Chevalier's early role was not completely clear-cut, and was only asserted retroactively, in the same year the U.S. patent was granted to others:

1858
CHARLES CHEVALIER (1804 - 1859)
...In 1858 Chevalier makes a claim that he used an iris diaphragm 18 years earlier (1840). Nicephore Niepce had used an iris diaphragm.

source: extract from the timeline found at: http://74.125.95.132/search?q=cache:7pGo9kBUFJsJ:www.precinemahistory.net/1850.htm+%22iris+diaphragm%22+lens+Chevalier&cd=5&hl=en&ct=clnk&gl=us&lr=lang_en|lang_de

Are you familiar with the whole story? Was there more to it?

[Ernest B.]

The timeline/source link I gave above (for Chevalier/1858) seems not to work. An effective address for the same page is: http://www.precinemahistory.net/1850.htm

[CCHarrison]

While the iris diaphragm does go way back and Harrison didnt "invent" it, Harrison was the first to use an adjustable iris shaped diaphragm inside the middle of the lens and was adjustable outside the lens barrel, which was to become the standard of how lenses were constructed.

Attached is Niepce's camera which shows the iris outside the camera box.

Dan

[Ernest B.]

"Attached is Niepce's camera which shows the iris outside the camera box."

Dan,

That gives clarity. Thanks.

[tenderobject]

anyone have tried this to their pretzval lens?

http://rover.ebay.com/rover/1/711-53...50387590122%09

[Steve Wright]

I'm watching that too. Might be a good way to attach an old lens and add a shutter.
Steve