Opmi-99 focus and skin stretching

The Opmi-99 I’m using has a 200 mm objective lens on it. However the depth of field is quite narrow (must be less than a couple of millimeters, maybe only a single mm) and though when first looking at the skin everything is in focus - as soon as I press down on the skin and stretch it, everything is moving away from the lens sufficiently to throw it out of focus. It’s very frustrating.

Anyone else experienced this and worked out how to resolve it.

*Btw, am placing this thread in this sub-forum as am not working professionally - just on friends, etc.

The higher magnification, the narrow DOF.
You have to adjust the focus after the skin is stretched and ready to work on it…