Any experience with the Nikon CFI BE Plan 20/0.40?

[Rylee Isitt]

Rik has in the past raved about the quality of both the Nikon CFI BE Plan 4x and 10x from the same set, with photo proof of the quality of this glass. I have been using the 10x and am having a great time with it, so the 4x is now on my shopping list.

They do seem to have some issues with aberrations on contrasty/shiny edges, but in many situations they look to be a good alternative to the Mitutoyo objectives.

Since we seem to be on a roll with this particular set of objectives, I am curious about the 20x from this set for use in microphotography of whole specimens without cover slips. And actually the rest of the set too, but the higher mag lenses likely need cover slips and would probably have to live on an actual microscope.

Has anyone had a chance to compare it to M plan objectives, or any other 20x objectives for that matter?

Thanks!