This is description of this part:
Microscope objective with RMS thread with 70x magnification, very high numerical aperture, equipped with a correction ring for cover glass thickness, designed for water immersion operation and with a phase contrast ring.
Manufacturer: Lomo
Model: APO-WI-F 70x1,23
Magnification: 70x
Numerical aperture: 1,23
Correction: Apochromat
Tube length: 160 mm
Focal length: 33 mm
Immersion: yes - water
Cover glass: yes - thickness from 0.10 to 0.20 mm
Markings: APO = Apochromat, WI = water immersion, F = phase contrast
Thread: RMS
Year of production: 1972
Note: to work in phase contrast technology you need a Lomo KF-4 condenser (you can see it in the database under number 00653).
This is a professional microscope objective with a very wide range of applications. The main features that make this objective exceptional:
- water immersion is preferred by many users over oil immersion
- very high numerical aperture, allowing the objective to produce a high resolution image
- cover glass thickness correction ring
Standard biological objectives are designed to achieve the best image quality when the specimen is located under a cover glass with a thickness of 0.17 mm (hence the marking on objectives such as 160/0.17). Unfortunately inexpensive cover glasses often do not undergo strict production control and a single package may contain cover glasses with thicknesses of 0.14 mm or 0.19 mm, which reduces observation sharpness.
Thanks to the built-in cover glass thickness correction ring (abbreviated CGTCR, CGCC or CGCR) the objective can be adjusted for every specimen so that it operates optimally. This works even when the actual thickness of the cover glass is unknown, because the effect is simply visible and the adjustment can be done "by eye".
Although this objective is a so-called "short" objective, meaning with a focal length of 33 mm, after adding a 12 mm adapter (you can see it in the database under number 99140) it can be used with newer microscopes designed for objectives with a focal length of 45 mm.
The Lomo company produced adapters specifically for these objectives (converters) from RMS thread to M27 thread, which makes them a very attractive option for installation in modern Zeiss Axio series microscopes.
What is this part needed for?
- If you want to upgrade your Lomo microscope with original parts
- If you need a 70x water immersion objective lens for Lomo, Carl Zeiss Jena, PZO, IOR, or other microscopes requiring 33mm and 160mm lenses
- If you have a Lomo microscope from 1972 (the serial number begins with "72") and want original-era objectives
- If you don't like oil immersion but want better image quality than standard, dry 60x / 63x objectives
