Rodenstock 150mm F5.6 Sironar

[seawolf66]

The above lens was made around the 70's There is a question I need answered , I hope some one here can answer it! [Is there a reason for the extra scale on the rodenstock lens , above the regular scale is a 420mm scale :: any thoughts of it or on it] I have some minimal knowledge on rectiliner lens the older type is this along those lines or is it something else?
thanks for any and all information on it::confused:

[Bob Salomon]

That is the scale you use when you remove either the front or rear group to convert the lens to a longer focal length lens of very low quality.

I always removed the rear group of cells to help protect the shutter blades as removing the front group leaves the blades and the shutter/aperture blade mechanisms very exposed to possible damage.

If the serial number on your lens is below 6,5xx,xxx or lower then it was made before the 70's.

[seawolf66]

Mr. Bob Salomon: Thnks for your response to my request for information. The lens # 8783605 to my knowledge it was made around 1973: So by takeing the rear element off it becomes a 420mm with very low picture quality!

Correct me if I am wrong here On rectilinar lens do not the lens just, switch places ? Very new to LF but am reading and learning!
Mr. Lauren MacIntopsh

[Bob Salomon]

Mr. Bob Salomon: Thnks for your response to my request for information. The lens # 8783605 to my knowledge it was made around 1973: So by takeing the rear element off it becomes a 420mm with very low picture quality!

Correct me if I am wrong here On rectilinar lens do not the lens just, switch places ? Very new to LF but am reading and learning!
Mr. Lauren MacIntopsh

No. You remove one lens group. Either the front group or the rear group.