Bonsoir,
un sacré lot avec 16 objectifs, un condenseur phase et une lunette de centrage dans un coffret bois!!!
DanielCrabbé a écrit :que signifient PLL et NM ?
La réponse est dans ma page:
http://www.lenaturaliste.net/portail/ar ... lympus-bh2
Je répète:
il y a 4 gammes d'objectifs pour contraste de phase en 37mm chez olympus selon la densité des plaques de phase et le rendu associé
PL: positive low
PLL: positive low low
NM : negative medium
NH: negative high
Les 4 séries se retrouvent pour les objectifs LB45mm en DAch, mais seulement en PL et en NH avec les Splan.
La réponse était aussi dans cette page que Fred nous a signalé il y a peu, sur les objectifs, de microscopyU:
http://www.microscopyu.com/print/articl ... print.html
Les 4 désignations (plus une) se retrouvent chez Nikon avec des lettres différentes:
"Phase contrast objectives are segregated into a number of categories depending upon the construction and neutral density of internal phase rings:
•DL (Dark Low) - DL objectives produce a dark image outline on a light gray background. These objectives are designed to furnish the strongest dark contrast in specimens having major differences in refractive indices. The DL phase contrast objective is the most popular style for examination of cells and other semi-transparent living material and is especially suited for photomicrography and digital imaging.
•DLL (Dark Low Low) - Similar to the DL objective, the DLL series allows better images in brightfield and is often used as a "universal" objective in microscope systems that utilize multiple illumination modes such as fluorescence, DIC, brightfield, and darkfield.
•ADL (Apodized Dark Low) - Recently introduced by Nikon, the apodized phase contrast ADL objectives contain a secondary neutral density ring on either side of the phase ring. Addition of the secondary rings assists in reducing unwanted "halo" effects often associated with imaging in phase contrast microscopy.
•DM (Dark Medium) - DM objectives produce a dark image outline on a medium gray background. These objectives are designed to be used for high image contrast with specimens having small phase differences, such as fine fibers, granules, and particles.
•BM (Bright Medium) - Often referred to as negative phase contrast, BM objectives produce a bright image outline on a medium gray background. BM objectives are ideal for visual examination of bacterial flagella, fibrin bundles, minute globules, and blood cell counting. "
