« on: January 21, 2013, 04:31:17 AM »
It is interesting to use old lenses like that. That particular lens is a "Rapid Rectilinear" and was common on middle grade consumer cameras of the day. But the aperture is not calibrated in f/stops. It is calibrated in what was called the "Uniform System". In US stops US 16 equals f/16. US 8 is f/11; US 4 (your lens) is f/8 etc.
The system was adopted as a standard by the Photographic Society of Great Britain in the 1880's. Many less expensive Kodak lenses used the system until somewhere in the 1920's.
Thanks for the info!
Still impressive at f/8. Consider that this would be the center of a 4¼" x 3¼" piece of film. If it was a sensor with the pixel density of my NEX-5N, it would be a 108mm x 803mm sensor with nearly 400 Mpix! Take a picture with *that* and crop the center, and you get the image that I posted. Impressively sharp I say!