New Oplar Lens 1:3.5 f=5cm
On Saturday June 24, 2023, I found at the photo trade exchange organized monthly by the "Maison de la Photographie", Saint-Bonnet- de-Mure, France, a new clean lens Oplar 1:3.5 f=5cm for my Foca camera's with the screw 36mm mount. This lens, with the serial number beginning by 032, was manufactured in 1947 by the Optique & Précision de Levallois (OPL) French company, most likely in its factory of Châteaudun, Eure, France. The lens was the normal. lens for screw-mount Foca's camera based on a Tessar-type formula with four lenses in three groups. The seller offered me the Foca AUV filter and I bought too an adapted DYMA x3.5 filter for the lens size (push-on filter 36mm diameter).
The filter is called "DYMA" due to the presence of neodymium in the glass giving an unusual absorption by bands in the visible spectrum. In particulier blue and yellow color ans more absorbed than the rest of the spectrum. The filter existed in two different versions with the coefficient x2.5 or 3.5.
After examination and cleaning of the lens and the filters in details, I did a test film using a Fomapan 400 exposed for 80 ISO to compensate y-the filter absorption. I used a Minolta Autometer III with a 10° finder for selective measurements privileging the shadow areas. I used my FOCA camera body PF2B year 1956 an the lens was also equipped for all the views with a Genaco metal shade hood.
Typical settings during the session : 1/100s f/8 to f/11 by this very bright and clear afternoon in Lyon, France.
Rue du Bon Pasteur, June 24, 2023
69001 Lyon
France
After exposure, the film was processed using Adox Adonal (Agfa Rodinal) developer at dilution 1+25, 20°C for 6 min.
The film was then digitalized using a Sony A7 body adapted to a Minolta Auto Bellows III and a Minolta Slide Duplicator using a lens Minolta Bellow Macro Rokkor 50mm f/3.5 at a reproduction ratio of 1:1. The reproduced RAW files obtained were processed in LR prior the the final JPEG editions.
All views of the film are presented in the dedicated album either in the printed framed versions and unframed full-size jpeg.
About the camera body :
The Foca type PF2B (PF for "Petit Format") was constructed in France by the company "Optique & Precision de Levallois" (OPL) starting from 1947. It was manufactured in the Chateaudun OPL factory, route de Jallans, France, in 1956 among a late series of the PF2B. The factory, constructed in 1938, is still at the same place under the name of SAFRAN now producing precision devices for aerospace appliances.
The camera is normally equipped with the collapsible OPLAR lens 1:2.8 f=5cm. The focal shutter of the PF2B has timing of 1/1000, 1/500, 1/200, 1/100, 1/50 and 1/25s plus the B pose. A slow exposure device below 1/25s could be installed by the aftermarket service and was installed basically for the FOCA PF3 and Foca Universel.
New Oplar Lens 1:3.5 f=5cm
On Saturday June 24, 2023, I found at the photo trade exchange organized monthly by the "Maison de la Photographie", Saint-Bonnet- de-Mure, France, a new clean lens Oplar 1:3.5 f=5cm for my Foca camera's with the screw 36mm mount. This lens, with the serial number beginning by 032, was manufactured in 1947 by the Optique & Précision de Levallois (OPL) French company, most likely in its factory of Châteaudun, Eure, France. The lens was the normal. lens for screw-mount Foca's camera based on a Tessar-type formula with four lenses in three groups. The seller offered me the Foca AUV filter and I bought too an adapted DYMA x3.5 filter for the lens size (push-on filter 36mm diameter).
The filter is called "DYMA" due to the presence of neodymium in the glass giving an unusual absorption by bands in the visible spectrum. In particulier blue and yellow color ans more absorbed than the rest of the spectrum. The filter existed in two different versions with the coefficient x2.5 or 3.5.
After examination and cleaning of the lens and the filters in details, I did a test film using a Fomapan 400 exposed for 80 ISO to compensate y-the filter absorption. I used a Minolta Autometer III with a 10° finder for selective measurements privileging the shadow areas. I used my FOCA camera body PF2B year 1956 an the lens was also equipped for all the views with a Genaco metal shade hood.
Typical settings during the session : 1/100s f/8 to f/11 by this very bright and clear afternoon in Lyon, France.
Rue du Bon Pasteur, June 24, 2023
69001 Lyon
France
After exposure, the film was processed using Adox Adonal (Agfa Rodinal) developer at dilution 1+25, 20°C for 6 min.
The film was then digitalized using a Sony A7 body adapted to a Minolta Auto Bellows III and a Minolta Slide Duplicator using a lens Minolta Bellow Macro Rokkor 50mm f/3.5 at a reproduction ratio of 1:1. The reproduced RAW files obtained were processed in LR prior the the final JPEG editions.
All views of the film are presented in the dedicated album either in the printed framed versions and unframed full-size jpeg.
About the camera body :
The Foca type PF2B (PF for "Petit Format") was constructed in France by the company "Optique & Precision de Levallois" (OPL) starting from 1947. It was manufactured in the Chateaudun OPL factory, route de Jallans, France, in 1956 among a late series of the PF2B. The factory, constructed in 1938, is still at the same place under the name of SAFRAN now producing precision devices for aerospace appliances.
The camera is normally equipped with the collapsible OPLAR lens 1:2.8 f=5cm. The focal shutter of the PF2B has timing of 1/1000, 1/500, 1/200, 1/100, 1/50 and 1/25s plus the B pose. A slow exposure device below 1/25s could be installed by the aftermarket service and was installed basically for the FOCA PF3 and Foca Universel.