Glossary
H
- half-wave compensator
- see half-wave plate
- half-wave plate
- An optical component that imparts a half-wave phase difference between light polarized parallel to its fast axis and parallel to its slow axis. It's commonly used to the rotate the plane of polarization of linearly polarized light.
- Synonyms: half-wave compensator
- See also: polarized light microscopy, polarization, birefringence, compensator, quarter-wave compensator
- halo
- An artifact common to phase contrast microscopy of large phase objects, where dark objects will appear to have a bright border and bright objects will appear to have a dark border. It is caused by weakly diffracted light traveling through the objective phase ring.
- Synonyms: halo effect
- See also: phase contrast, phase contrast microscopy, apodized phase contrast
- halo effect
- see halo
- halogen illuminator
- see halogen lamp
- halogen lamp
- A light source featuring a sealed chamber containing a tungsten filament and halogen gas that produces light with wavelengths spanning the visible spectrum. Halogen lamps are principally used for techniques such as brightfield, phase contrast, and differential interference contrast (DIC).
- Synonyms: tungsten-halogen lamp, halogen illuminator
- See also: filament lamp, illuminator, bulb, light emitting diode
- hardware against software piracy (HASP)
- A small device (typically USB) that unlocks software capabilities when plugged in to a computer as an attempt to reduce software piracy. For example, only verified users possessing the key may utilize proprietary software.
- hardware-triggered acquisition
- A strategy in which integrated hardware components communicate directly without the need to pass through a facilitating software. For example, illumination, filter rotation, and camera acquisition can be triggered by the camera exposure signal to greatly increase overall acquisition rate by reducing software overhead.
- heat filter
- A filter designed to attenuate infrared wavelengths, reducing heating of the sample and potential damage to optical components.
- Synonyms: IR filter, infrared filter
- See also: filter, infrared radiation
- heated stage
- see live cell imaging
- heating stage
- A stage designed to maintain high temperatures and heat a sample to maintain physiological conditions, perform thermal analysis techniques, and more.
- Synonyms: heated stage
- See also: stage
- hematoxylin and eosin (H&E)
- A pair of stains that highlight nuclei with a blue hue (hematoxylin) and cytoplasm or extracellular matrix material with a pink hue (eosin). Patterns in staining inform a wide variety of medical diagnoses.
- high content
- see high content imaging
- high content imaging
- A technique in which many multi-labeled samples under a variety of conditions are imaged. This requires automated acquisition and analysis routines, and is often used for applications like drug screening.
- Synonyms: high content, high content screening, high content microscopy
- See also: high throughput imaging, phenotypic screening
- high content microscopy
- see high content imaging
- high content screening
- see high content imaging
- high power objective (HP)
- An objective lens rated to withstand particularly high laser power without damage, useful for techniques such as single molecule localization microscopy where high power lasers are tightly focused in the objective back aperture.
- See also: objective lens
- high throughput
- see high throughput imaging
- high throughput imaging
- A technique in which many samples (commonly 96-well plates) are imaged via automated acquisition processes, sometimes accompanied by sample loading robotics. This technique is widely used in drug discovery.
- Synonyms: high throughput screening, high throughput
- See also: high content imaging, phenotypic screening
- high throughput screening
- see high throughput imaging
- high-eyepoint eyepiece
- A specialized eyepiece with a longer focal length on the viewer-side of the optics. This is useful for users wearing glasses. These objectives may include an "H" or "HE" inscription.
- See also: eyepiece, focal length
- Hoffman modulation contrast
- see modulation contrast
- homogenous immersion
- A system in which the refractive index of the optical path through the sample has minimal variability. This requires immersion media between the condenser lens and sample, refractive index-matched mounting media, and immersion oil between the sample and objective lens. This minimizes optical aberrations.
- See also: refractive index, immersion medium, aberration, immersion, immersion lens, immersion objective
- hot mirror
- see shortpass filter
- hot pixel
- A pixel that exhibits unusually high intensity values due to leakage current. Fundamentally caused by imperfections in the manufacturing process and typically exacerbated by higher temperature. This artifact can be corrected by averaging that particular pixel position with adjacent pixels.
- Synonyms: stuck pixels, sparkle
- See also: pixel, camera
- Huygenian eyepiece
- see Huygens eyepiece
- Huygens eyepiece
- An eyepiece consisting of two lens elements with an intermediate image plane and associated stop between.
- Synonyms: Huygenian eyepiece, internal-diaphragm eyepiece
- See also: eyepiece, Ramsden eyepiece, Kellner eyepiece
