Inverted Nikon Tms Microscope. Hoffman Modulation Contrast.excl. Condition

US $2400

Saint-Laurent, Quebec, Canada
Nov 3rd

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On sale is a binocular NIKON TMS INVERTED microscope equipped with HOFFMAN MODULATION CONTRAST.The microscope is in excellent cosmetic,mechanical and optical condition.Both coarse and fine focusing are excellent.The unit comes with the following three objectives: NIKON Achromatic 4x/0.10/160 Two objectives (10x,20x ) marked "Hoffman modulation contrast" objectives. The condenser has three positions: One is regular brightfield,while the other two have Hoffman Modulators. It also has the necessary Hoffman polarizer. There are two NIKON CFWE 10x/18 eyepieces. The binocular head has ONE "socket" focusable for very easy focusing and balancing the image. Excellent halogen illumination,satisfactory at all included magnifications. The Hoffman Modulation Contrast method is used to observe transparent samples that are virtually invisible in Brightfield.It will turn those transparent images into well-contrasted tri-dimensional images . The Hoffman Modulation is by far superior to Phase Contrast; It provides clear images without the halo so characteristic to the Phase Contrast. It produces images very similar and usually better than the Nomarski [DIC] method. And it is useful for the same type of samples:transparent or almost transparent. Professional labs and most professionals do no longer use the Phase Contrast,but the Hoffman Modulation Contrast. This microscope is medium size,relatively light and easy to handle,but stable. NOTE ON HOFFMAN MODULATION CONTRAST (HMC) The Hoffman modulation contrast (HMC) microscope is a method by which transparent, or nearly so, objects can be visualized. Hoffman Modulation Contrast accentuates phase gradients within the sample and displays them in the image plane as levels of gray modulated lighter and darker than an average background gray. To accomplish this, a special filter is placed in the Fourier plane (back focal plane) of the objective conjugate to another filter, the condenser slit. The HMC microscope exploits phase gradients within the sample. In regions where there is a rapid spatial change of sample optical path, refraction will occur, slightly shifting the path refracted light.17 Light passing through negative amplitude gradients (light to dark) within the sample will be refracted through the dark zone of the modulator and be rendered darker. Light that passes through homogeneous areas within the sample will experience no refraction and pass through the central gray region of the modulator and be rendered uniformly light gray. Light passing through positive gradients (dark to light) will be refracted through the light zone and remain bright. Thus, light passing through the modulator is accentuated in contrast and results in an image with pseudo-relief (much like DIC) with the three-dimensionality representative of light phase gradients rather than actual object geometry. Unlike DIC, HMC uses no beam-splitting prisms.Polarizing filters are placed optically in front of the sample. Thus, HMC can be used with birefringent specimens not amenable to DIC (e.g., crystalline objects or specimens in plastic Petri plates). The only adjustment required for a microscope equipped with Hoffman modulation contrast is to align the slit condenser filter with the orientation of the modulator in the objective.Rotate and/or translate the filter until the slit edges aligns with the objective's modulator. Please ask any question you might have well before the auction's end. 14 days money-back guaranty if not satisfied.