Microscope Magnification Tables for Ernst Leitz Objectives
Details of the magnification and focal lengths can be found in Ernst Leitz Catalog No. 40. 1
Eyepieces
| Eyepiece | Magnification |
|---|---|
| I | ~5× |
| II | ~7× |
| III | ~10× |
| IV | ~12–15× |
| Swift EC5R eyepiece camera | ~26-39× |
| AmScope MD35 eyepiece camera | ~49-62x |
Objective Lenses
| Objective | Approx focal length | Magnification |
|---|---|---|
| No. 3 | ~16 mm | ~10× |
| No. 6 | ~4 mm | ~40× |
Magnifications
Objective No. 3
| Eyepiece | Objective | Total Magnification |
|---|---|---|
| II | No. 3 | ~70× |
| IV | No. 3 | ~120–150× |
| Swift EC5R eyepiece camera | No. 3 | ~260-390× |
| AmScope MD35 eyepiece camera | No. 3 | ~490-620x |
Objective No. 6
| Eyepiece | Objective | Total Magnification |
|---|---|---|
| II | No. 6 | ~280× |
| IV | No. 6 | ~450–600× |
| Swift EC5R eyepiece camera | No. 6 | ~1040-1560× |
| AmScope MD35 eyepiece camera | No. 6 | ~1960-2480x |
Reporting Magnification
Magnification is calculated as:
Total Magnification = Objective Power x Eyepiece Power
It was reported in “diameters”, the period term for magnification. So, for example, using objective No. 6 and eyepiece IV, the magnification would have been reported as follows:
Observed with Leitz Objective No. 6 and Eyepiece IV (approx. 480 diameters).
Estimating Effective Camera Power
The eyepiece cameras do not specify a magnification but their effective power can be estimated using the following method:
- Secure a stage micrometer on the stage
- Select an objective and eyepiece, in this instance No. 3 and IV, respectively
- Select a micrometer scale that will span the full field
- Adjust the illumination and bring the micrometer scale into focus
- Measure the diameter of the field, Wo
- Replace the eyepiece with the camera of interest
- Adjust the illumination as needed and bring the micrometer scale into focus
- Measure the diameter of the field, Wc
- Calculate the effective power of the eyepiece camera as follows:
Where Po is the eyepiece power.
The camera effective power for the MD35 and EC5R cameras was determined in this way but as eyepiece IV has magnifying power in the range ~12-15x, a range is obtained for each, as shown in the tables above.
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Catalogue No. 40, Microscopes and Accessory Apparatus, Ernst Leitz, Wetzlar, 1903, Project Gitenberg, https://www.gutenberg.org/files/35842/35842-h/35842-h.htm ↩