Foca filter Dyma
A Fomapan Action 400 black-and-white film to test the effect a the special Foca filter "Dyma" produced in France in the 50's.
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. Here the 42mm push-on Foca Dyma filter used is a x 3.5.
As a consequence, I exposed the Foma 400 for 80 ISO using a Minolta Autometer III with a 10° finder for selective measurements privileging the shadow areas. I used my FOCA camera PF2B year 1956 and its normal Oplar lens1:2.8 f=5cm equipped for all the views with the Dyma filter and a Genaco metal shade hood.
Typical settings during the session : 1/100s f/8 to f/11.
Rue des Fantasques, May 29, 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 and the lens:
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 equipped with the collapsible OPLAR lens (a Tessar formula) 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.
Foca filter Dyma
A Fomapan Action 400 black-and-white film to test the effect a the special Foca filter "Dyma" produced in France in the 50's.
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. Here the 42mm push-on Foca Dyma filter used is a x 3.5.
As a consequence, I exposed the Foma 400 for 80 ISO using a Minolta Autometer III with a 10° finder for selective measurements privileging the shadow areas. I used my FOCA camera PF2B year 1956 and its normal Oplar lens1:2.8 f=5cm equipped for all the views with the Dyma filter and a Genaco metal shade hood.
Typical settings during the session : 1/100s f/8 to f/11.
Rue des Fantasques, May 29, 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 and the lens:
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 equipped with the collapsible OPLAR lens (a Tessar formula) 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.