Flange Focal distance Adjustment

[Stephen Williams]

Hi All,

 

Can anybody explain how to measure the FFD on a RED camera? I assume that using a depth gauge is a bad idear.

 

Note 35mm PL lenses focus at a FFD of 52.00mm, unlike video lenses, do not have a back focus adjustment. With a film camera a steel block is put in the gate, as a base to measure from. Arri cameras are usually set to 51.98 so that perfect focus is into the film.

 

 

Stephen

[Olex Kalynychenko]

Hi All,

 

Can anybody explain how to measure the FFD on a RED camera? I assume that using a depth gauge is a bad idear.

 

Note 35mm PL lenses focus at a FFD of 52.00mm, unlike video lenses, do not have a back focus adjustment. With a film camera a steel block is put in the gate, as a base to measure from. Arri cameras are usually set to 51.98 so that perfect focus is into the film.

Stephen

 

You will need use autocollimator.

You can use comparison method with standard FFD tools.

The some autocolimators have ruler, and, if you will have special tables you can calculate real FFD.

Arri cameras with normal speeds have FFD 51.98 mm, the high speed ( 150 fps ) 51.96 mm.

[Stephen Williams]

You will need use autocollimator.

 

Hi Olex,

 

Will that really work on a chip camera? I thought autocollimators were not that accurate.

 

 

Many thanks,

 

Stephen

[Greg Lowry]

post deleted by writer

Edited October 1, 2006 by Greg Lowry