Olympus IX71 Inverted Hoffman Modulation Contrast HMC Laboratory Microscope

Olympus IX71 Inverted Fluorescence Hoffman Modulation Contrast Microscope Built for live cell imaging. Olympus has equipped its IX2 series microscopes with the new UIS2 optical system precisely to meet those demands. With its high S/N ratio, its compensation for chromatic aberration over a much wider wavelength range and its flat, high transmittance , this new system sets a new world standard of fluorescence performance — efficiently detecting even faint fluorescence signals without damaging the cell, and optimizing multi-color observation. Delivering unprecedented image quality over a super wide light spectrum, the IX2 inverted system microscope will be your live cell instrument of choice now and in the future. The basic microscope configuration for Hoffman Modulation Contrast is illustrated in Figure 1. An optical amplitude spatial filter, termed a "modulator" , is inserted on the back focal plane of an achromat, planachromat or planfluorite objective . Light intensity passing through this system varies above and below an average value, which is then said to be modulated. Objectives theoretically useful for modulation contrast can cover the entire magnification range of 10x to 100x but nowdays mainly used in IVF for oocyte and or embryo observation. That´s why Olympus has optimized the HMC with their Olympus Relief Contrast (ORC) objectives featuring long working distances for preferred use with the inverted IX3 microscope. The modulator for Hoffman or Olympus Relief Contrast has three zones that are depicted in Figure 2: a small, dark zone near the periphery of the back focal plane which transmits only one percent of light (areas marked "D" in Figure 2); a narrow gray zone which transmits 15 percent (areas marked "G" in Figure 2); and the remaining clear or transparent zone, covering most of the territory at the back of the objective, which transmits 100 percent of the light (areas marked "B" in Figure 2). Unlike the phase plate in phase contrast microscopy, the Hoffman modulator is designed not to alter the phase of light passing through any of the zones. When viewed under modulation contrast optics, transparent objects that are essentially invisible in ordinary brightfield microscopy take on an apparent three-dimensional appearance dictated by phase gradients. The modulator does not introduce changes in the phase relationship of light passing through different portions of the modulator, but influences the principal zeroth order maxima. Higher order diffraction maxima are unaffected. Measurements using a Michelson interferometer confirm that the phase changes of light passed through a Hoffman-style modulator varies (if any) by a factor of less than λ/20.