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DIC

Wikipedia:  DIC microscopy

In 1947, Francis Hughes Smith filed for a differential interference contrast patent
using paired Wollaston prisms,
with one prism located where phase plates are inside phase contrast objectives.
However, precisely manufacturing and aligning Wollaston prisms inside objectives
is prohibitively tedious and expensive.

Nomarski's 1952 patent enabled locating DIC prisms outside objectives,
where they can relatively easily be aligned.
DIC prism manufacture remains fairly fussy, and Nomarski's practice of licensing
only one microscope manufacture per country helped limit supply and keep prices high.

Zeiss-Nomarski differential interference equipment for transmitted-light microscope

  by R.D.Allen, G.B.David, G.Nomarski

Wollaston vs Nomarski prisms

                           
                Wollaston                                         Nomarski
The front interference plane of an objective-side Nomarski prism
must coincide with the objective's back focal plane.
The upper wedge must be thinner than the lower wedge in a Nomarski prism,
but most drawings just have a diagonal straight line between corners.
Small but important difference.
Understanding waveplates and retarders

See also:  Polarized macro and micro photography e.g. for compensators and retardation plates.

Olympus diascopic DIC Configuration and Alignment

Nikon's microscopyu.com DIC articles

DIC Principles and Applications
DIC Component Alignment (Java)
de Senarmont DIC Microscope Configuration
de Senarmont Bias Retardation

fixes 1/4 wavelength retardation plate, while polarizer can rotate +/- 45 degrees.

epi DIC

Optiphot epi DIC is strictly brightfield; DIC sliders block coaxial illumination.

Scarodactyl: Reflected Light - Optiphot Series

What you need to look out for is the polarizer and analyzer.
The best option has a rotatable polarizer
with a separate quarter wave plate slider,
mostly meant for epi DIC but good without too.

Scarodactyl's epi DIC woes
Scarodactyl's Diatoms in epi DIC

PeteM: DIC options compared

Nikon Eclipse favored for De Senarmont system and long WD

hkv: DIC setup

Look down an eye tube without eyepiece,
you should see a white circle with a black stripe across the middle if DIC is properly aligned (b):

abednego1995: 3 generations of Optiphot DIC

1st and 2nd use a single translating Nomarski prism above objectives;
3rd Senarmont type has dedicated prisms per objective.

rogeliomoreno's diascopic DIC considerations

  1. The objective's prism and the condenser's prism must match.
    I did try to use Nikon objective's prisms (made for the N2 condenser's prism) with M condenser's prism
    and they did not work.
  2. Condenser prism are made to be mounted at precise distance from the condenser's lens, close to focal point.
  3. Prisms have to be oriented 45 degrees from polarizer direction
    (Polarizer is typically oriented left-right and analyzer back-front)
    First, find objective prism's orientation:
    remove both prisms from the light train,
    and cross the polarizer and analyzer
    (light through eyepieces is darkest),
    now put the objective's prism in the light train,
    remove an eyepieces and check for the black line:
    • it should be oriented at 45 degrees,
    • note: not all prisms show the black stripe when put between crossed polarizers
      (the Nikon N1, N2 family of DIC prisms do not show that stripe, but mostly do).
      Second, orient the condenser prism's black stripe in the same direction
      (/ or \\) as the objective's stripe,
      by removing the objective prism from the light train
      inserting the condenser prism, and
      turning that prism until its black stripe aligns with the objective's.

Nikon epi DIC prisms repurposed - viktor j nilsson

JH's epi DIC with mirror

  • First surface mirror

    First steps in exploring (Zeiss) epi DIC

    Epi-DIC for gemstone surface examination

    NicoVB: table salt and DIC

    "let salt soak in water and let the water evaporate.
    I just put my slide on the central heating to speed up.
    But i was not happy with the forms, so i did it a second time.
    Then mixed with alcohol."

    DIC interference fringe altered by tilting prisms

    DIC prism interference band location

    by measuring objective's back focal plane using a laser pointer

  • project distance to 0 diameter e.g. using gnuplot fit
    viktor j nilsson:


    Nikon 10x,40x and 100x epi objectives uses the same prism (labelled 10.40.100x),

    but 20x and 5x objectives have separate prisms.

    DIC with non-DIC CF plan Nikon objectives?

    DIC prisms work at objectives' back focal plane
    (which is often inside objectives, requiring Nomarski prisms)

    Gerd: bright field epi DIC DVD/CD

    Nikon upper DIC prism for 160 TL is integrated with objective nosepiece

    Nikon epi DIC prisms in transmitted DIC Phase Contrast condenser

    NIH: DIC shear modulation by LCD

    DIC by Savart plates used on Nikon S

  • Differential interference contrast microscopy using Savart plates

    Alternatives

    Esslinger + Gross: DIC vs PlasDIC; partially coherent illumination


    PlasDIC is a special design of Köhler-DIC configuration in which a slit in the direction of shear
    is placed symmetrically with respect to the optical axis in the FFP of the condenser.
    Köhler-DIC uses an condenser aperture of the same size as objective aperture.

    DIY DIC includes:

    DIC microscopy with adjustable plastic Sanderson prisms

    Kristiansen Illumination PDF

  • 2022 Nikon Small World video
  • on Facebook
    • Use one of these three filters in the condenser.
      A regular darkfield stop works, but these work best.
    • put a coverslip with Scotch Magic translucent tape on the condenser, tape side down.
    • add microscope slide, fine tune illumination by diaphragms and condenser height

    varable amplitude contrast (VAC)

  • "Arthur Strange's Variable Amplitude Contrast Method - VAC 2"

  • Balsam Post Colour Supplements - Cumulative Index

    Nomarski-like effects with simple filter  

    Differential Interference Contrast (DIC) and other methods of producing contrast

    MicrobeHunter forum discussion

    Quekett:  Theory of contrast control - Jeremy Sanderson

    • maintained by blekenbleu