MicrobeHunter.com Microscopy Forum

Yes, Norland's NOA 61 is a good one for bonding glass to glass/metal.

This one looks like a Neo 20x objective, so yes, tube length is 210mm.

It has nothing to do with the DIC prism, it supposed to be focused w/ or w/o the prism if it's a good one.
Most likely this Neo SPlan 50 NIC objective is damaged.