Vintage

This really is a bit special. Cooke Troughton and Sims elliptic compensator not only complete with its original case and instructions but it also has its original protector

This set dates from the time when phase contrast microscopy was just starting to emerge and the various makers were trying to avoid copyright issues. Baker had developed a condenser system with a bright field cross that matched with retarding crosses in objectives to produce the ''phase' effect. This set has a 'cross' condenser with a x10 'cross' phase objective, x10 bright field (non phase) and x100 'cross' phase together with a phase telescope for alignment. All presented in the original excellent case. A collectors must

In the early days of phase contrast microscopy, different manufacturers adopted very different mechanisms to avoid issues with copyright (until it was agreed lawfully that you cannot copyright a concept). At this time Baker used a cross system with a condenser that let light through a cross system to be intercepted by a cross retardation in the objective. This is a good example of the 'cross' phase condenser with a lever that allows the cross to partially rotate which presumably allows it to match the cross in the objective.