This project started at the Red User Party in 2010 when Mark Pederson from Off Hollywood and Ketch Rossi in all of his eccentric, awesome style. Ketch approached me about adding marks to his Red Pro Primes noting that there were a few key marks that were left out. I’m not sure why certain marks were included or excluded, but the focus scale is a non linear helix design. This means that the spacing of the focus distance marks is restricted to the mechanical travel of the helix threads. Duclos Lenses had modified focus scale in the past. Even going to the extent of fabricating and engraving an entirely new scale from scratch in some cases. But the RPP really only required a few added marks. I thought it would be nice to go over the process of adding marks so that you can see what exactly is being done
Ketch sent me his RPP 18mm through 100mm. First thing required is to ensure all of the existing marks are accurate and the flange depth or back focus is set properly. From this point we put each lens on the projector and determine which distances can be added with the given space. The distance is measured accurately then the lens is focused critically. The position the scale is at is where the witness is temporarily pencil marked. This gives our engraver the location for the mark.
Once the lens markings are all in place the scale is removed and sent off to be engraved. When the scale comes back the lens is partially assembled in order to calibrate infinity focus and re-attach the scale in the appropriate position. After the scale is positioned the rest of the lens is put back together and everything is secured. After the lens is re-assembled entirely all of the glass and exterior surfaces are cleaned and the lens is as good as new.