dIY DIC

Here you can discuss different microscopic techniques and illumination methods, such as Brightfield, Darkfield, Phase Contrast, DIC, Oblique illumination, etc.
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Hugh
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Joined: Wed Jul 17, 2019 7:13 am

Re: dIY DIC

#31 Post by Hugh » Fri Dec 20, 2019 12:17 am

Hi - just invested in a Nikon Eclipse 55i - which was supposed to be DIC (the objectives have DIC marked on them - but appear to be completely normal objectives (am I missing something?) - there is a polarizer and an analyser (in the headstage) - nothing resembling prisms.
What is missing - there appears to be a dearth of information on this. Also - looking for a x100 (infinity optics) objective for this. Maybe contact me
hugh@austrop.org.au

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wporter
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Location: USA

Re: dIY DIC

#32 Post by wporter » Fri Dec 20, 2019 12:39 am

The objectives marked 'DIC' don't have internal prisms, but rather have high-quality strain-free & occlusion-free optical glass. There is still a need for a prism external to and above the objective, and one below the objective.

See the below page for a nice color graphic (Fig. 1) of a DIC optical system showing the components.

Quote:
"Objectives designed for differential interference contrast must be free of strain or birefringent occlusions that depolarize light and lead to image degradation. In the past, microscopists were limited to strain-free achromat and fluorite objectives intended for observations in polarized light, but modern objectives having higher correction factors can now be employed for DIC microscopy. Termed universal objectives, these advanced lens systems can often be used for combined DIC, fluorescence, phase contrast, and brightfield microscopy without having to change objectives. In addition, newer apochromatic objectives have been designed that are sufficiently strain free to enable their use in polarized light and differential interference contrast observation, dramatically improving the image quality and resolution at higher magnifications."

from https://www.olympus-lifescience.com/en/ ... iguration/

Hugh
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Joined: Wed Jul 17, 2019 7:13 am

Re: dIY DIC

#33 Post by Hugh » Fri Dec 20, 2019 2:00 am

Thanks for that
Unfortunately my server won't display the link - seems it has security issues.. (?!)

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RobBerdan
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Re: dIY DIC

#34 Post by RobBerdan » Mon Jan 20, 2020 5:39 am

I have DIC, Hoffman and I used oblique illumination which the article refers to. I believe the author has now purchased DIC. DIC is unfortanetly very expensive to make. A number of researchers have been working on developing software that is supposed to simulate DIC or Phase contrast, but none has answered my emails. Still I believe it will come in the future.

Oblique illumination can easily be created by simply moving your filter holder to partially obscure the incoming light. It might work better with certain objectives. Hoffman modulation - simulates DIC but only in Black and white and is useful because most forms of DIC can't be used with plastic tissue culture dishes. Zeiss offers a version of DIC for plastic dishes, but it is inferior to real DIC.

Below I have attached 3 images 1) Hoffman Modulation contrast 2) Oblique pseudo DIC and 3) Real DIC
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