Finding focal length of old lens
Hopefully somebody can help me with this.......
I have a 1/2 plate camera called 'The International' made by Lancaster & Son of Birmingham, of about 1886 vintage. The brass lens is wonderful & has excellent optics!
I would just like to know what the actual focal length is and/or how to work this out, e.g.- 6 inch??
Written on the lens is - "J. Lancaster & son, Birmingham, 1/1 pl patent, Rectigraf". The F stops are F/1 - F32
The lens is 2 inches diameter, by 3 inches in (total) length.