Carl Zeiss
2.5
Objectives
The objectives are the optical heart of the microscope. The objectives may be labeled as follows:
Plan-ACHROMAT 10×/0.25 ∞/-.
Fig. 2
Objective
Objective magnification multiplied by eyepiece magnification results in overall visual magnification, e.g.
10 x 10 = 100x.
Numerical aperture multiplied by 1000, e.g. 0.25 × 1000 = 250×, presents the maximum useful
magnification; there is no resolution for further details above that limit.
When immersion objectives are used, the air between the cover slip and the objective is replaced by a
liquid, which in most cases is immersion oil. The plastic oiler containing 5 ml of immersion oil is
particularly suitable for this purpose.
Because of their short working distances, the 40×, 40x/Ph 2 and 100x/Oil objectives are equipped with
resilient mounts for specimen protection.
12
Description
where:
10×
Objective magnification,
With a defined color ring on the
objective being assigned to each
magnification step (Carl Zeiss color code)
0.25
Numerical aperture
∞
Infinite mechanical tube length
−
Usable with cover slip thickness D = 0 or
0.17 mm
or
0.17
Usable with cover slip thickness
D = 0.17 mm
Other labels:
Oil
Oil immersion objective
Ph 2
Phase contrast objective with green
inscription and phase stop Ph 2
Primo Star
B 46-0071 v 03/06