Delta Stage with short 10x objective lens

I put together the Delta stage using this 10x objective lens and struggled a bit since it didn’t get close enough to the slide. Ended up moving the objective screw hole a bit further down on the optics module casing so that I could raise the objective closer to the slide.

Now I’m trying to use reflection illumination and the reflection illumination holder is bumping up against the main body, preventing the objective from getting close to the slide.

Any suggestions for what I should do? Do I just need to buy an objective that is longer? Screwed in, the one I have only extends about 27mm from the top of the optics module casing.

Thanks,
Ben

The details in the link do not give one piece of information for the lens - the par-focal distance. This is the distance from the shoulder of the RMS thread to the focal plane of the lens. You can measure this in your microscope. It does not need to be accurate, there are two common standards - 45mm or 35mm. It sounds as though you have a lens designed for 35mm. We usually use lenses with 45mm par-focal distance. Most things on the microscope and delta are designed so that 35mm will still work but we do not routinely test this and some things may be a problem.