Steven Tribe
27-Feb-2013, 06:07
I used to think that magic lantern lenses were attached to a bell housing by some kind of adapter which would function as as flange for mounting the "Petzval" on a camera.
For once, I got hold of a projection petzval, which included the brass housing.
It turned out that the thread on the housing was not separable from the housing.
As the brass is somewhat thinner than the usual lens mount, I hoped that a hacksaw job and a bit of metal work would produce a reasonable flat and strongth enough flange.
Anyway, the 1st photo shows the complete assembly. The barrel part has been unsoldered and the profile formed front has been hacksawed to provide a flange edge of about 1/2". The bell shaped profile can be seen in photo 2.
I screwed the lens sleeve into the "flange" thread to ensure that the thin brass did not become distorted during metal work.
The complete assembly was "dropped" into a solid support. In this case it was an extra cyliinder block for a prewar form SV engine which just happened to have the right bore! 5 minutes are careful work removed the profile. But other supports could be used!
The, very satisfactory to me, result is in the last photo.
Working with brass is very dependent on it's thickness - but fortunately magic lantern housings are thin (0.7mm).
For once, I got hold of a projection petzval, which included the brass housing.
It turned out that the thread on the housing was not separable from the housing.
As the brass is somewhat thinner than the usual lens mount, I hoped that a hacksaw job and a bit of metal work would produce a reasonable flat and strongth enough flange.
Anyway, the 1st photo shows the complete assembly. The barrel part has been unsoldered and the profile formed front has been hacksawed to provide a flange edge of about 1/2". The bell shaped profile can be seen in photo 2.
I screwed the lens sleeve into the "flange" thread to ensure that the thin brass did not become distorted during metal work.
The complete assembly was "dropped" into a solid support. In this case it was an extra cyliinder block for a prewar form SV engine which just happened to have the right bore! 5 minutes are careful work removed the profile. But other supports could be used!
The, very satisfactory to me, result is in the last photo.
Working with brass is very dependent on it's thickness - but fortunately magic lantern housings are thin (0.7mm).