new mfg Nikon 10X NA 0.25 finite objective looks very good - www.photomacrography.net
Achromatic super contrast objective ASC 10X/0.25 (WD=6.4mm)
10X Infinity-Corrected Plan Achromatic POL Polarizing Microscope Objective Lens Working Distance 5.03mm with Black Finish | View Solutions Microscope Store
10X Plan Achromatic Objective Lens with Knurled Ring – AmScope