I have been thinking about doing some 5X4 colour work in addition to the B & W. I have an old 135/235 converable Symmar lens in a Synchro Compur shutter that de livers good sharp pictures. A local dealer has a 150mm APO Symmar for sale at a reasonable price. Aside from the difference in focal length would I benefit from upgrading ? One benefit I see myself is moving up from 40.5 filter thread so I can get an adapter for my filtr holder system rather than adapters and stepping rings. I would have to believe that I would get better contrast and probably col our rendition. Sharpness is probably not an issue at the enlargement size that I commonly do.

Thanks, in advance

Dave