Better 3 facet prism

I am fairly new to the Studio Spots. While I have owned them for a year and fixed problems, I have actually not used them at a live event yet. I will be tomorrow.

What I find is that the 3 facet prism, the Images are too tight (overlap too much). I think martin does the prism best.

is there a replacement prism that has a better spread of the images? Where could I buy one to try?

Has anyone else changed any of the other effect? if so, what else have you used?
Related