I think you need a different lens.
This link will initially seem to have nothing to do with your problem, but bear with me: http://www.khbphotografix.com/omega/LensMountD5.htm
The reason this chart may help you is that an Omega D5/D6 only works with certain 50mm lenses because the bellows has to be tightly compressed to work with 35mm film and a 50mm lens. And when the bellows is tightly compressed, a lens that protrudes through the lens mount fouls the mounting system.
If you look through the chart, you will see that very few 50mm lenses work with the shallow 421-105 lens mount. Those 50mm lenses are more likely to work with your enlarger.
This link will initially seem to have nothing to do with your problem, but bear with me: http://www.khbphotografix.com/omega/LensMountD5.htm
The reason this chart may help you is that an Omega D5/D6 only works with certain 50mm lenses because the bellows has to be tightly compressed to work with 35mm film and a 50mm lens. And when the bellows is tightly compressed, a lens that protrudes through the lens mount fouls the mounting system.
If you look through the chart, you will see that very few 50mm lenses work with the shallow 421-105 lens mount. Those 50mm lenses are more likely to work with your enlarger.




