This fluorite (semi-apochromat) objective is equipped with an adjustable collar that affords flexibility in imaging through vessels with a thickness from 0 (no coverslip) to 2.0 mm. With four-color correction for spherical and chromatic aberrations, it delivers exceptional image quality. For the sharpest image simply set the collar to the thickness of the vessel/coverslip you are using. If the thickness is unknown, turn the collar in either direction while monitoring the sample focus. All Olympus objectives are compatible with EVOS cell imaging systems and offer outstanding optical performance from visible to near-infrared light. The extensive selection of EVOS and Olympus objectives satisfies needs across the spectrum of magnifications and optical specifications.

Additional characteristics of this Olympus objective:
• Magnification: 20X
• Numerical Aperture: 0.45
• Working Distance: 6.6–7.8 mm
• Superb image quality

Image quality
Microscope objectives may be the most important components of a microscope because they are responsible for primary image formation. High image quality is crucial to experimental success and often a requirement for publication; Olympus objectives afford that quality across the visible spectrum to near infrared light. This performance results from years of lens manufacture experience, and the broad selection of objectives means that you can choose the optimal objective for your imaging requirements.

Objective classes

Achromat objectives are perfect for general applications, with standard correction of color and focus.

Fluorite objectives deliver excellent resolution and are made with higher numerical apertures than achromat objectives, resulting in brighter fluorescence signal and higher contrast imaging. The higher optical quality greatly reduces optical aberrations, and corrections for color and focus are at higher levels than achromat objectives. Fluorite objectives are ideally suited for fluorescence and demanding transmitted light applications, where the higher contrast make them ideally suited for color imaging.

Apochromat objectives are manufactured to the highest levels of resolution, fluorescence brightness, and contrast; chromatic aberrations are almost eliminated. They are recommended for the most demanding applications, particularly at magnifications of 60x and above. Apochromatic objectives are the best choice for the capture of color images in white light.

Brightfield contrast versus phase contrast objectives
Brightfield is the most basic form of light microscopy and is accomplished by sample absorption of light. A higher density area in a sample will absorb more light, thus increasing contrast in those areas. Phase contrast objectives are most useful for hard to see, translucent specimens. This method of contrast is accomplished by converting phase shifts, caused by light passing through a translucent specimen, into brightness changes (i.e., contrast).

Long working distance versus coverslip-corrected objectives
Long working distance (LWD) objectives are optimized for use through vessels with a nominal wall thickness of 0.9-1.5 mm. This includes vessels commonly used in cell culture and cell-based assays, such as slides, cell culture dishes and flasks, microtiter well plates, etc. Coverslip-corrected objectives are optimized for use through #1.5 coverslips (thickness approximately 0.17 mm). These objectives have a higher magnification/NA ratio and provide higher resolution compared to LWD objectives.

For additional choices, visit the EVOS objectives selection guide.
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