I had an opportunity to use water dipping objective lenses from different manufacturers and was surprised to learn that the length of the dipping cone was so different from one to another. As shown below, Zeiss objective lenses have much longer dipping cones (the whitish, non-metalic part that can be immersed in water) than Nikon or Olympus. The Zeiss IR Achroplan 40x/0.80 W is the longest.
- Objective “Achroplan” 40x/0.80 W 440090-9901-000 [no longer available] (micro-shop.zeiss.com)
- Objective W N-Achroplan 40x/0.75 M27 420967-9900-000 (micro-shop.zeiss.com)
- Nikon CFI Fluor 40XW (nikoninstruments.com Objective Selector)
- Olympus Aqueous Immersion Objectives (olympusmicro.com)
- Dipping Cone (http://zeiss-campus.magnet.fsu.edu)