This is description of this part:
Top lens with low numerical aperture A 0.3 for the Lomo OI-14 oblique light condenser.
Note: the designation OI-14 is written in the Latin alphabet. On the condenser, the model name is written in Cyrillic and looks similar to ON-14.
The Lomo OI-14 condenser has a removable (unscrewable) top lens:
- A1.4 with high aperture, for use with objectives with high numerical aperture (which corresponds to high magnifications, it can be assumed above 40x)
- A0.3 with low aperture, for use with low magnification objectives
Although it is possible to work with low magnification objectives (e.g. 5x or 10x) using a condenser with the A1.4 lens installed - the image is too "sharp" and contrasty. In this case, replacing the lens with A0.3 allows obtaining a pastel, soft and visually pleasant image.
Since the Lomo OI-14 condenser has been produced since the 1960s, over the years this additional lens has very often been lost and most condensers available on the secondary market have only one - most often A1.4.
The Lomo OI-14 condenser has a mounting diameter of 37 mm, but since it is very popular among microscope users, an extension ring is often used, allowing it to be mounted in microscopes with a 39.5 mm condenser holder. This condenser fits microscopes from various manufacturers: Lomo, PZO, Zeiss, Carl Zeiss Jena, Meopta, IOR, Olympus, ROW, Nikon, Leitz Wetzlar and many others.
What is this part needed for?
- if you have a Lomo OI-14 condenser without any lens
- if you have a Lomo OI-14 condenser only with the A1.4 lens and want to have both
