This is description of this part:
Planachromatic microscope objective with 40x magnification for the Motic BA210 and BA310 microscopes.
Manufacturer: Motic
Marking on the objective: Motic EF-N Plan 40x/0.65 ∞/0.17
Magnification: 40x
Correction: PLAN achromatic
Optical system: CCIS (Color Corrected Infinity System - part of the image correction is performed by the tube lens of the Motic stand, which is why the objective is intended for stands of this brand)
Numerical aperture N.A.: 0.65
Working distance W.D.: approx. 0.4-0.5 mm
Tube length: infinity
Parfocal distance: 45 mm
Field number F.N.: 20
Cover glass: yes, 0.17 mm thick
Immersion: no (this is a dry objective)
Thread: RMS
Spring-loaded mount: yes - the front mount retracts when pressed against the specimen, which at a working distance of about half a millimetre saves both the objective and the cover glass
Lead-free glass: yes - the mount carries the crossed-out Pb symbol
Colour ring: blue, according to the colour code for 40x magnification
Objectives of the EF-N Plan series were the factory equipment of the older generation of the Motic BA210 and BA310 microscopes, while the newer models of these series, designated Elite (BA210E, BA310E), are fitted with the next-generation EC Plan objectives - this objective is therefore the correct spare part for the older stands and not for the Elite versions.
Mechanically this objective can be screwed into the nosepiece of many other microscopes, since the RMS thread and the 45 mm parfocal distance are standard - a correct image, however, cannot be obtained that way.
- in older stands corrected for 160 mm it will not work, because it is an infinity-corrected objective and requires a tube lens
- in stands of other manufacturers, including infinity-corrected ones, a residual aberration remains, because part of the correction is performed by the tube lens of the CCIS system, which is built into the stand of the Motic microscope and matched by the manufacturer to exactly this optics
- in the remaining Motic microscopes with the CCIS system the objective does produce an image, but it is not the factory choice for them - in stands with field number 22 it runs out of field, and in inverted stands it runs out of working distance.
What is this part needed for?
- if you own the Motic BA210 / Motic BA310 microscope and this objective is missing
- if you already have such an objective in your microscope, but it is in very poor condition or damaged
- if you want to have such an objective as a spare
