LB Eyepieces for Olympus BH2 Microscopes
Click here to see detailed specifications of the LB eyepieces.
Eyepieces in the LB optical family were available in multiple varieties. Standard 23mm diameter versions were made to provide 5x, 8x, 10x, 12.5x, 15x, and 20x magnifications (which were suitable for the various field number 20 objectives), and 30mm diameter versions were made to provide 8x and 10x magnifications (which were suitable for the field number 26.5 objectives). The following eyepiece types were available: 1) CWHK eyepieces (high-eyepoint, field number 18), which were made to pair with the educational E objectives. 2) WK eyepieces (standard eyepoint, field number 20) and WHK eyepieces (high eyepoint, field number 20), which were made to pair with the A and DPlan objectives. 3) NK eyepieces, which were special versions to provide very low (5x, standard eyepoint, field number 21) and very high (20x, low eyepoint, field number 10) magnifications. 4) SWK eyepieces (standard eyepoint, field number 26.5) and SWHK eyepieces (high eyepoint, field number 26.5), which were made to pair with the SPlan objectives.
See the image below for a comparison of the field coverage for FN 18, FN 20, and FN 26.5. The various 23mm eyepieces were compatible with the standard binocular and trinocular viewing heads, while the 30mm eyepieces were compatible with the super-wide binocular and trinocular heads. Versions of the various eyepieces were available with internal optical graticules, for specific measurement applications, and helicoid focusing, for custom graticule use.
LB Eyepiece Types
EDUCATIONAL EYEPIECES: There were educational eyepieces made for the CH2 microscope that can be used on the BH2. These eyepieces have a 23mm barrel with a limited field of view of FN 18, and a high eyepoint. These were intended to be matched with the EA educational achromatic objectives. Educational eyepieces were available in the following versions:
- CWHK 10x, FN 18
- GS CWHK 10x, FN 18, with 8 grain size reticle.
STANDARD-EYEPOINT EYEPIECES: There were many standard-eyepoint eyepieces made for the BH2 scope. These eyepieces have a 23mm barrel with a field of view of FN 20. Standard eyepoint eyepieces were offered in the following versions:
- WK 10x, FN 20
- WK 10x, FN 20, with helical focus for reticle usage.
- MICRO WK 10x, FN 20, with 10/100 micrometer reticle.
- CROSS WK 10x, FN 20, with cross micrometer reticle.
HIGH-EYEPOINT OBJECTIVES: There were many high-eyepoint eyepieces made for the BH2 scope. These eyepieces have a 23mm barrel with various fields of view, and have a higher eyepoint than the corresponding standard eyepoint version. High-eyepoint eyepieces were available in the following versions:
- WHK 8x, FN 20
- WHK 10x, FN 20
- GS WHK 10x, FN 20, with 8 grain size reticle
- MICRO WHK 10x, FN 20, with 10/100 micrometer reticle
- CROSS WHK 10x, FN 20, with cross micrometer reticle
- 35 WHK 10x, FN 20, with 35mm framing mask
- P WHK 10x, FN 20, with 3-1/4″ x 4-1/2″ Polaroid mask
- 4×5 WHK 10x, FN 20, with 4″ x 5″ Polaroid mask
- WHK 10x -H, FN 20, with helical focus for reticle usage.
- WHK 12.5x, FN 16
- WHK 12.5x -H, FN 16, with helical focus for reticle usage.
- WHK 15x, FN 14
SUPER-WIDE EYEPIECES: There were a few super-widefield, high-eyepoint eyepieces made for the BH2. These eyepieces, which have a field number of 26.5 and a 30mm barrel, are intended for use with the super-wide binocular and trinocular heads. Super-wide eyepieces were available in the following versions:
- SWHK 8x, FN 26.5
- SWHK 10x , FN 26.5
- 35 SWHK 10x, FN 26.5, 35mm photo mask
- P SWHK 10x, FN 26.5, 3-1/4″ x 4-1/2″ Polaroid mask
- 4×5 SWHK 10x, FN 26.5, 4×5 Polaroid mask
OTHER EYEPIECES: There were two eyepieces labeled as “NK” that are suitable for the BH2. These were available in the following versions:
- NK 5x, FN 21
- NK 20x, FN 10
Note that all of the eyepieces in the LB family provide correction for the lateral chromatic aberration that is present, by design, in the intermediate real image produced by LB objectives. These eyepiece will not perform properly when used with objectives from other manufacturers.
The table below shows they various reticle sizes used in the various LB eyepieces.
