Olympus microscopes and photomicrographic equipment

Objective designations for BH and BH-2 microscopes

Detailed information about the biological and metallurgical objectives that were designed for Olympus compound microscopes of the BH era (AH, BH, CH, CK, IMT) can be found in the Olympus High Quality Optics catalogue on the downloads page.

The specifications of the biological objectives that were designed for Olympus compound microscopes of the BH-2 era (AH-2, BH-2, CH-2, CK2, CK40, IMT-2) can be found in the Olympus LB Objective Series for Biological Use catalogue on the downloads page.

Olympus 45 mm objectives

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.

Letters before the magnification

LettersTube lengthParfocal lengthThreadNotes
(none)160 mm36.65 mmRMSAchromat
A160 mm45 mmRMSAchromat, referred to as D in catalogues
Apo160 mm36.65 mmRMSApochromat
C160 mm36.65 mmRMSAchromat, correction for viewing up through a culture vessel or slide, normally used on inverted microscopes
CPL160 mm36.65 mmRMSAchromat, phase contrast (positive low), correction for viewing up through a culture vessel or slide, normally used on inverted microscopes
DApo160 mm45 mmRMSApochromat
DPlan160 mm45 mmRMSAchromat, flat field up to F.N. 20
DPlanApo160 mm45 mmRMSApochromat, flat field up to F.N. 20
EA160 mm45 mmRMSAchromat, education or economy series
FL160 mm36.65 mmRMSAchromat with fluorite elements
LWDC160 mm36.65 mmRMSAchromat, long working distance, correction for viewing up through a culture vessel or slide, normally used on inverted microscopes
LWDCA160 mm45 mmRMSAchromat, long working distance, correction for viewing up through a culture vessel or slide, normally used on inverted microscopes
LWDCDPlan160 mm45 mmRMSAchromat, flat field, long working distance, correction collar (or correction for viewing up through a culture vessel or slide), normally used on inverted microscopes
LWDCPlan160 mm36.65 mmRMSAchromat, flat field, long working distance, correction for viewing up through a culture vessel or slide, normally used on inverted microscopes
LWDMPlan210 mm36.65 mmRMSMetallurgical achromat, flat field, long working distance
LWDMSPlan∞ f=18045 mmRMSMetallurgical achromat, superwide flat field, long working distance
LWDMSPlanApo∞ f=18045 mmRMSMetallurgical apochromat, superwide flat field, long working distance
LWDNeoSPlanApo∞ f=18045 mm26 mmMetallurgical apochromat, brightfield/darkfield, superwide flat field, long working distance
M210 mm36.65 mmRMSMetallurgical achromat (BH versions are 210 mm tube length, older versions for the MF are 200 mm tube length)
MA∞ f=18045 mmRMSMetallurgical achromat
MDPlan∞ f=18045 mmRMSMetallurgical achromat, flat field up to F.N. 20
MNH210 mm36.65 mmRMSMetallurgical achromat, phase contrast (negative high)
MNM210 mm36.65 mmRMSMetallurgical achromat, phase contrast (negative medium)
MPL210 mm36.65 mmRMSMetallurgical achromat, phase contrast (positive low)
MPlan210 mm36.65 mmRMSMetallurgical achromat, flat field
MPLL210 mm36.65 mmRMSMetallurgical achromat, phase contrast (positive low low)
MPO200 mm36.65 mmRMSMetallurgical achromat, strain-free for polarising applications
MSPlan∞ f=18045 mmRMSMetallurgical achromat, superwide flat field up to F.N. 26.5
MSPlanApo∞ f=18045 mmRMSMetallurgical apochromat, superwide flat field up to F.N. 26.5
MUVFL∞ f=18045 mm26 mmMetallurgical achromat with fluorite elements, fluorescence-free, for fluorescence applications
NCDPlanFL160 mm45 mmRMSAchromat with fluorite elements, flat field up to F.N. 20, no coverslip
NCSPlan160 mm45 mmRMSAchromat, superwide flat field up to F.N. 26.5, no coverslip
NCSPlanApo160 mm45 mmRMSApochromat, superwide flat field up to F.N. 26.5, no coverslip
NCUVFL160 mm45 mmRMSAchromat with fluorite elements, fluorescence-free, for fluorescence applications, no coverslip
NDA160 mm45 mmRMSAchromat
NEA160 mm45 mmRMSAchromat, newer version of the EA education or economy series
Neo210 mm36.65 mm25 mmMetallurgical achromat, brightfield/darkfield
NeoDPlan∞ f=18045 mm26 mmMetallurgical achromat, brightfield/darkfield, flat field up to F.N. 20
NeoPlan210 mm36.65 mm25 mmMetallurgical achromat, brightfield/darkfield, flat field
NeoSPlan∞ f=18045 mm26 mmMetallurgical achromat, brightfield/darkfield, superwide flat field up to F.N. 26.5
NH160 mm36.65 mmRMSAchromat, phase contrast (negative high)
NM160 mm36.65 mmRMSAchromat, phase contrast (negative medium)
PL160 mm36.65 mmRMSAchromat, phase contrast (positive low)
Plan160 mm36.65 mmRMSAchromat, flat field
PlanApo160 mm36.65 mmRMSApochromat, flat field
PlanPL160 mm36.65 mmRMSAchromat, phase contrast (positive low), flat field
PLL160 mm36.65 mmRMSAchromat, phase contrast (positive low low)
PO160 mm36.65 mmRMSAchromat, strain-free for polarising applications, for BH and Vanox microscopes
PS160 mm36.65 mmRMSAchromat, strain-free for polarising applications, for POS microscope
SPlan160 mm45 mmRMSAchromat, superwide flat field up to F.N. 26.5, strain-free for polarising applications and Nomarski DIC
SPlanApo160 mm45 mmRMSApochromat, superwide flat field up to F.N. 26.5
SPlanFL160 mm45 mmRMSAchromat with fluorite elements, superwide flat field up to F.N. 26.5
ULWDCDPlan160 mm45 mmRMSAchromat, flat field, ultra long working distance, correction collar, normally used on inverted microscopes
ULWDMIRPlan∞ f=18045 mmRMSMetallurgical achromat for infra-red applications, flat field, ultra long working distance
ULWDMSPlan∞ f=18045 mmRMSMetallurgical achromat, superwide flat field, ultra long working distance
ULWDNeoSPlan∞ f=18045 mm26 mmMetallurgical achromat, brightfield/darkfield, superwide flat field, ultra long working distance
UVFL160 mm45 mmRMSAchromat with fluorite elements, fluorescence-free, for fluorescence applications
WIMSPlanApo∞ f=18045 mmRMSMetallurgical apochromat, superwide flat field, for water immersion
WPlan160 mm45 mmRMSAchromat, flat field, for water immersion
WPlanApo160 mm45 mmRMSApochromat, flat field, for water immersion
WPlanFL160 mm45 mmRMSAchromat with fluorite elements, flat field, for water immersion

The 36.65 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

LettersNotes
FPLPositive Low phase contrast, for use with the combined 10/20/40 annulus on CK30 and CK40 inverted microscopes
NHNegative High phase contrast (subject lighter than background, for specimens of relatively low contrast)
NICNomarski Interference Contrast
NMNegative Medium phase contrast (subject lighter than background, for specimens of average contrast)
PLPositive Low phase contrast (subject darker than background, for specimens of relatively high contrast)
PLLPositive Low Low phase contrast (subject darker than background, for specimens of high contrast)
POStrain-free, for polarising applications
RPRelief Phase contrast, for use with special condenser and slider on inverted microscopes
UVFluorescence-free, for fluorescence applications
UVPLFluorescence-free, for fluorescence applications, and positive low phase contrast

Characters after the tube length

On the 36.65 mm parfocal lenses, these numbers appear below the numerical aperture.

CharactersNotes
/–Can be used with or without a coverslip
/0Corrected for use without a coverslip
/0–2Adjustable correction for viewing up through slides or culture vessels of thicknesses up to 2 mm, normally used on inverted microscopes
/0.11–0.23Adjustable correction for coverslips of thicknesses from 0.11 to 0.23 mm
/0.14–0.20Adjustable correction for coverslips of thicknesses from 0.14 to 0.20 mm
/0.17Corrected for use with a 0.17 mm coverslip; the most common correction
0.4–1.0Adjustable correction for viewing up through slides or culture vessels of thicknesses from 0.4 to 1.0 mm, normally used on inverted microscopes
/1Corrected for viewing up through a 1 mm slide or culture vessel, normally used on inverted microscopes
/1.2Corrected for viewing up through a 1.2 mm slide or culture vessel, normally used on inverted microscopes
1.20Corrected for viewing up through a 1.20 mm slide or culture vessel, normally used on inverted microscopes

Other letters

LettersNotes
dryImmersion oil must not be used; appears only on high magnification lenses
HIHomogeneous immersion; immersion oil must be used between the objective and the slide, and should be used between the condenser and the slide
LWDLong working distance
NOCOVERCorrected for use without a coverslip
oilImmersion oil must be used between the objective and the slide, and should be used between the condenser and the slide
SISilicone immersion; silicone oil must be used between the objective and the slide
SilSilicone immersion; silicone oil must be used between the objective and the slide
WaterWater immersion; water must be used between the objective and the slide
WIWater 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 Olympus BH microscope

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”.

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Created 10th December 2010   —   Updated 17th February 2012
Copyright © 2010–2012 Alan Wood

Olympus microscopes and photomicrographic equipment

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