Olympus microscopes and photomicrographic Objective designations for BH and BH-2

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D

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Objectives for the BH, BH-2 and other Olympus microscopes of this era have the series, for example “SPlan”, in front of the magnification. Objectives for the BX and other more recent Olympus microscopes have the series above the magnification, and cannot be used with older microscopes.

The following tables are intended as a quick reference to the letters that Olympus used on its objectives in the BH and BH-2 era.

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Letters before the magnification

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Letters Tube length Parfocal length Thread Notes
(none)
           160 mm 36.65 mm         RMS Achromat
A            160 mm 45 mm RMS Achromat, referred to as D in catalogues
Apo            160 mm 36.65 mm RMS Apochromat
C            160 mm 36.65 mm RMS Achromat, correction for viewing up through a culture vessel or slide, normally used on inverted microscopes
CPL            160 mm 36.65 mm RMS Achromat, phase contrast (positive low), correction for viewing up through a culture vessel or slide, normally used on inverted microscopes
DApo    160 mm 45 mm RMS Apochromat

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DPlan    160 mm 45 mm RMS Achromat, flat field up to F.N. 20
DPlanApo      160 mm 45 mm RMS Apochromat, flat field up to F.N. 20
EA            160 mm 45 mm RMS Achromat, education or economy series
FL            160 mm 36.65 mm RMS Achromat with fluorite elements
LWDC    160 mm 36.65 mm RMS Achromat, long working distance, correction for viewing up through a culture vessel or slide, normally used on inverted microscopes
LWDCA    160 mm 45 mm RMS Achromat, long working distance, correction for viewing up through a culture vessel or slide, normally used on inverted microscopes
LWDCDPlan   160 mm 45 mm RMS Achromat, flat field, long working distance, correction collar (or correction for viewing up through a culture vessel or slide), normally used on inverted microscopes
LWDCPlan   160 mm 36.65 mm RMS Achromat, flat field, long working distance, correction for viewing up through a culture vessel or slide, normally used on inverted microscopes
LWDMPlan 210 mm “long mount” RMS Metallurgical achromat, flat field, long working distance
LWDMSPlan ∞ f=180 45 mm RMS Metallurgical achromat, superwide flat field, long working distance
LWDMSPlanApo ∞ f=180 45 mm RMS Metallurgical apochromat, superwide flat field, long working distance
LWDNeoSPlanApo ∞ f=180 45 mm 26 mm Metallurgical apochromat, brightfield/darkfield, superwide flat field, long working distance
M 210 mm 36.65 mm or “long mount” RMS Metallurgical achromat (Older versions for the MF are 200 mm tube length and 36.65 mm parfocal, BH versions are 210 mm tube length and were made in 36.65 mm and “long mount” versions)
MA ∞ f=180 45 mm RMS Metallurgical achromat
MDPlan ∞ f=180 45 mm RMS Metallurgical achromat, flat field up to F.N. 20
MNH 210 mm ? 36.65 mm or “long mount” RMS Metallurgical achromat, phase contrast (negative high)
MNM 210 mm ? 36.65 mm or “long mount” RMS Metallurgical achromat, phase contrast (negative medium)

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MPL 210 mm ? 36.65 mm or “long mount” RMS Metallurgical achromat, phase contrast (positive low)
MPlan 210 mm 36.65 mm or “long mount” RMS Metallurgical achromat, flat field, made in 36.65 mm and “long mount” versions
MPlan N 210 mm “long mount” RMS Metallurgical achromat, flat field, strain free for interference contrast
MPLL 210 mm ? 36.65 mm or “long mount” RMS Metallurgical achromat, phase contrast (positive low low)
MPO 200 mm 36.65 mm RMS Metallurgical achromat, strain-free for polarising applications
MSPlan ∞ f=180 45 mm RMS Metallurgical achromat, superwide flat field up to F.N. 26.5
MSPlanApo ∞ f=180 45 mm RMS Metallurgical apochromat, superwide flat field up to F.N. 26.5
MUVFL ∞ f=180 45 mm 26 mm Metallurgical achromat with fluorite elements, fluorescence-free, for fluorescence applications
NCDPlanFL 160 mm 45 mm RMS Achromat with fluorite elements, flat field up to F.N. 20, no coverslip
NCSPlan 160 mm 45 mm RMS Achromat, superwide flat field up to F.N. 26.5, no coverslip
NCSPlanApo 160 mm 45 mm RMS Apochromat, superwide flat field up to F.N. 26.5, no coverslip
NCUVFL 160 mm 45 mm RMS Achromat with fluorite elements, fluorescence-free, for fluorescence applications, no coverslip
NDA 160 mm 45 mm RMS Achromat
NEA 160 mm 45 mm RMS Achromat, newer version of the EA education or economy series
Neo 210 mm “long mount” 25 mm Metallurgical achromat, brightfield/darkfield
NeoDPlan ∞ f=180 45 mm 26 mm Metallurgical achromat, brightfield/darkfield, flat field up to F.N. 20
NeoPlan 210 mm “long mount” 25 mm Metallurgical achromat, brightfield/darkfield, flat field
NeoSPlan ∞ f=180 45 mm 26 mm Metallurgical achromat, brightfield/darkfield, superwide flat field up to F.N. 26.5
NH 160 mm 36.65 mm RMS Achromat, phase contrast (negative high)
NM 160 mm 36.65 mm RMS Achromat, phase contrast (negative medium)
PL 160 mm 36.65 mm RMS Achromat, phase contrast (positive low)
Plan 160 mm 36.65 mm RMS Achromat, flat field
PlanApo 160 mm 36.65 mm RMS Apochromat, flat field
PlanPL 160 mm 36.65 mm RMS Achromat, phase contrast (positive low), flat field
PLL 160 mm 36.65 mm RMS Achromat, phase contrast (positive low low)
PO 160 mm 36.65 mm RMS Achromat, strain-free for polarising applications, for BH and Vanox microscopes
PS 160 mm 36.65 mm RMS Achromat, strain-free for polarising applications, for POS microscope
SPlan 160 mm 45 mm RMS Achromat, superwide flat field up to F.N. 26.5, strain-free for polarising applications and Nomarski DIC
SPlanApo 160 mm 45 mm RMS Apochromat, superwide flat field up to F.N. 26.5
SPlanFL 160 mm 45 mm RMS Achromat with fluorite elements, superwide flat field up to F.N. 26.5
ULWDCDPlan 160 mm 45 mm RMS Achromat, flat field, ultra long working distance, correction collar, normally used on inverted microscopes
ULWDMIRPlan ∞ f=180 45 mm RMS Metallurgical achromat for infra-red applications, flat field, ultra long working distance
ULWDMSPlan ∞ f=180 45 mm RMS Metallurgical achromat, superwide flat field, ultra long working distance
ULWDNeoSPlan ∞ f=180 45 mm 26 mm Metallurgical achromat, brightfield/darkfield, superwide flat field, ultra long working distance
UVFL 160 mm 45 mm RMS Achromat with fluorite elements, fluorescence-free, for fluorescence applications
WIMSPlanApo ∞ f=180 45 mm RMS Metallurgical apochromat, superwide flat field, for water immersion
WPlan 160 mm 45 mm RMS Achromat, flat field, for water immersion
WPlanApo 160 mm 45 mm RMS Apochromat, flat field, for water immersion
WPlanFL 160 mm 45 mm RMS Achromat with fluorite elements, flat field, for water immersion
The “short mount” (36.65 mm parfocal) and the “long mount” (approximately 42.5 mm parfocal) objectives were intended for microscopes of the BH era (AH, BH, CH, CK, IMT) and earlier models. For photomicrography, they should be used with the FK photo eyepieces. The eyepieces for viewing do not include an “L” in their designation, for example Bi WF10×.

The 45 mm parfocal long-barrel (LB) objectives were intended for microscopes of the BH-2 era (AH-2, BH-2, CH-2, CK2, CK40, IMT-2). For photomicrography, they should be used with the NFK photo eyepieces. The eyepieces for viewing include an “L” (indicating long barrel) in their designation, for example SWHK 10×L, WHK 10×/20 L, WHK 15×L or CWHK 10×/18L.

Letters after the magnification
Letters Notes
FPL Positive Low phase contrast, for use with the combined 10/20/40 annulus on CK30 and CK40 inverted microscopes
IC Strain free, for Nomarski Interference Contrast
N Strain free, for interference contrast.
NH Negative High phase contrast (subject lighter than background, for specimens of relatively low contrast)
NIC Strain free, for Nomarski Interference Contrast
NM Negative Medium phase contrast (subject lighter than background, for specimens of average contrast)
PL Positive Low phase contrast (subject darker than background, for specimens of relatively high contrast)
PLL Positive Low Low phase contrast (subject darker than background, for specimens of high contrast)
PO Strain-free, for polarising applications
RP Relief Phase contrast, for use with special condenser and slider on inverted microscopes
UV Fluorescence-free, for fluorescence applications
UVPL Fluorescence-free, for fluorescence applications, and positive low phase contrast
Characters after the tube length
On the 36.65 mm parfocal and “long mount” lenses, these numbers appear below the numerical aperture.

Characters Notes
/– Can be used with or without a coverslip
/0 Corrected for use without a coverslip
/0–2 Adjustable correction for viewing up through slides or culture vessels of thicknesses up to 2 mm, normally used on inverted microscopes
/0.11–0.23 Adjustable correction for coverslips of thicknesses from 0.11 to 0.23 mm
/0.14–0.20 Adjustable correction for coverslips of thicknesses from 0.14 to 0.20 mm
/0.17 Corrected for use with a 0.17 mm coverslip; the most common correction
0.4–1.0 Adjustable correction for viewing up through slides or culture vessels of thicknesses from 0.4 to 1.0 mm, normally used on inverted microscopes
/1 Corrected for viewing up through a 1 mm slide or culture vessel, normally used on inverted microscopes
/1.2 Corrected for viewing up through a 1.2 mm slide or culture vessel, normally used on inverted microscopes
1.20 Corrected for viewing up through a 1.20 mm slide or culture vessel, normally used on inverted microscopes
Other letters
Letters Notes
dry Immersion oil must not be used; appears only on high magnification lenses
HI Homogeneous immersion; immersion oil must be used between the objective and the slide, and should be used between the condenser and the slide
LWD Long working distance
NOCOVER Corrected for use without a coverslip
oil Immersion oil must be used between the objective and the slide, and should be used between the condenser and the slide
SI Silicone immersion; silicone oil must be used between the objective and the slide
Sil Silicone immersion; silicone oil must be used between the objective and the slide
Water Water immersion; water must be used between the objective and the slide
WI Water immersion; water must be used between the objective and the slide
Metallurgical objectives and vertical illuminators
The metallurgical objectives are intended to be used with reflected light from a vertical illuminator that is fitted between the stand and the head. They can also be used with transmitted light via the substage condenser, but a vertical illuminator is still needed to provide the proper 210 mm tube length or a tube lens.

For the M, MPlan, Neo and NeoPlan 36.65 mm parfocal objectives for the BH microscope, the illuminators are part grey and part black. The BH-MA is for the brightfield M and MPlan objectives, and the BH-RLA is for the brightfield/darkfield Neo and NeoPlan objectives; the BH-RLA can be distinguished by a knob labelled “PULL BF”. The objectives are corrected for the longer tube length (210 mm) caused by the vertical illuminator. A few of these illuminators are all black, but they can be distinguished from the BH2 versions by the absence of the “∞ f=180” label.

BH-RLA brightfield/darkfield vertical illuminator (for BH microscope with BH-NRE nosepiece and Neo or NeoPlan 36.65 mm metallurgical objectives)

For the MA, MDPlan, MSPlan, NeoDPlan and NeoSPlan 45 mm parfocal objectives for the BH-2 microscope, there were 2 series of illuminators. The first series is all black, the BH2-MA Brightfield Vertical Illuminator for the MA, MDPlan and MSPlan objectives, and the BH2-RLA Brightfield/Darkfield Vertical Illuminator for the NeoDPlan and NeoSPlan objectives; the BH2-RLA can be distinguished by a knob labelled “PULL BF”. Both black illuminators were replaced by the cream BH2-UMA Universal Vertical Illuminator, which can be fitted with the BH2-UBF brightfield cube and/or the BH2-UDF darkfield cube; the active cube can be selected by a sliding knob on the front. Both series of BH2 vertical illuminators include the tube lens (f = 180 mm) that is essential for these infinity-corrected objectives, and are labelled “∞ f=180”.