Specifications:

• Infinity Plan Achromatic Objective
• 10X Magnification Power / Numerical Aperture 0.25
• Working distance is about 14mm
• RMS thread

The Infinity Objective lens can only work with a tube lens. You can use 180mm focal length lens as a tube lens. The magnification will vary if you use other focal length. For example with a 250mm lens the magnification will be (250/180)*10=13.88

By using this formula as a reference the Depth of Field = 0.55 / (0.25 x 0.25) = 8.8 μm

Testing image using 4X Infinty Plan Objective with raynox 150 reversed, 35 micron step length, 22 pictures focus stacked. Resized only.