View Full Version : Berthiot perigraphe

Jose Luiz Vasconcellos
14-Jun-2000, 07:04
Does anyone know the construction of Berthiot perigraphe lenses? I found yesterd ay here at Rio de Janeiro, two of them: a 90mm F14 and a 120mm F14 too. They are equipped with wheel-stops and I'm wondering if they have the same construction of old protars (four elements, two groups) or are even simpler. I saw some of th ese lenses being sold at e-bay. Any information would be appreciated.

David A. Goldfarb
14-Jun-2000, 12:40
I have one (120mm/f:14), purchased recently from JCR cameras in the UK before he started putting them up on eBay, and I think it's a neat lens. I just had Steve Grimes mount mine in an Ilex 3 shutter. It's extremely compact, covers 8x10 at f:44 (the smallest aperture with the wheelstops--an Ilex 3 only stops down to f:32 with this lens, but one does gain a slightly wider aperture at the other end) with a bit of movement and about 1-1/2 stops of falloff from center to edge, and produces a nearly rectilinear image. I'm not sure whether the construction is two or four elements, but there are two groups.

Nze christian
14-Jun-2000, 14:11
these lens cover 1050 the old model closed at 56 and the new at 44 so the 90 cover 5*7 and the 120 cover 8*10 it also exist in 60, 75, 135), 150,180,200, 250 the 90 and 120 are the most findable of the series.

Pete Andrews
15-Jun-2000, 06:04
The Perigraphe is similar to the Goerz Dagor in construction. It's a six element lens made up of two symmetrical cemented triplet groups. The nominal coverage angle is stated as 65 degrees, but like the Dagor it increases greatly with stopping down.

David A. Goldfarb
19-Jun-2000, 14:02
http://www.echonyc.com/~goldfarb/photo/perigraphe1.jpg http://www.echonyc.com/~goldfarb/photo/perigraphe2.jpg

If you're curious to see how the mounting job came out, here are two images.