This is description of this part:
Achromatic microscope objective made by Nikon, with 40x magnification and a 45 mm parfocal length.
Manufacturer: Nikon (Japan)
Magnification: 40x
Colour correction: achromatic
Model: E 40 0.65 160/0.17
Numerical aperture N.A.: 0.65
Cover glass: yes, 0.17 mm thick
Thread: RMS
Tube length: 160 mm
Parfocal length: 45 mm (long barrel objective)
Immersion: no
Operating mode: objectives marked "E." are already CF objectives (CFN to be precise) and need no additional correction
This objective needs no additional correction from a tube lens or from the eyepieces. That makes it possible to fit it to microscopes of other makes, and in photomicrography it works in direct projection mode (it throws the image straight onto the camera sensor, with no relay optics needed).
This is the so-called black series of objectives, named after the black plastic barrel. They were used mainly in the Nikon Alphaphot YS2 microscope. That was the period when manufacturers were experimenting with a new look for microscope parts, and exactly the same black series appeared for instance in the Leitz / Leica HM-LUX 3 microscope or in the Will Wetzlar V300 / V355 / V365 microscopes.
This objective fits practically any microscope of any make, provided it has an RMS thread and supports objectives with TL = 160 mm and parfocal lengths of 33 / 37 and 45 mm. A few such microscopes are listed in the "compatibility" section, but that list is not complete.
What is this part needed for?
- if you have a Nikon Alphaphot YS2 microscope without a 40x objective and want to complete it with original parts
- if you are looking for a good-quality 40x objective for a microscope from another manufacturer
- if you already have such an objective, but it is of very poor quality and you want to replace it with a working one
- if you want to keep such objective in reserve