Blueberries and other experiments

curt0909 · Post by **curt0909** » Thu May 24, 2012 8:58 am

The first image is of a stink bug's eye. Specimen had been dead for over a year. 'Through objective lighting' using my lego epi-illumination attachment. 3w flashlight>linear polarizer>Nomarski prism>50/50 mirror>10x Nikon BD plan>50/50 prism>Nomarski prism>linear polarizer>2.5x Nikon CFPL> Canon 600D This is quite different than production Epi DIC systems. It is the clearest image I've obtained using reflected light through the objective.

The second image was made with a homemade phase anullus placed directly on glass diffuser. Zeiss 40x neofluar phase objective. Dried water on a slide

RogelioMoreno · Post by **RogelioMoreno** » Fri May 25, 2012 4:12 am

Interesting. I hope to try epi DIC in the future, with epi DIC you use only one DIC prism.

Rogelio

curt0909 · Post by **curt0909** » Fri May 25, 2012 10:15 pm

I just purchased a Nikon BD Plan Epi DIC nose piece with 5x 20x 40x 100x prisms. I just need a Nikon DF BF epi illuminator with polarizers to complete the scope.

The most common method for epi DIC is using one prism. I tried that setup yesterday and got a different result than this photo. It worked best with a 20x objective and looked like oblique lighting.

Pau · Post by **Pau** » Sun May 27, 2012 3:08 am

Your second image is clearly a phase contrast one, with its typical dark blue lines and halos.
But about the fist one... it just seems cross polarization with incomplete extintion (light reflection at the ommatidia).
I'm also experimenting with epi DIC with biological specimens, but without good results. It seems that this technique is only adequate for metallic reflective materials.

curt0909 · Post by **curt0909** » Mon May 28, 2012 10:46 am

Yes Pau I agree its certainly not similar to well calibrated DIC. The following night I used a single prism directly above the objective with a different result. It was similar to oblique illumination and had a shiny quality. It only gave this effect when used with a 20x objective. But it should be noted that even when prisms are not 'matched' for an objective they are still providing some degree of interference. Sometimes a low contrast is desirable as it provides more resolution than a 'normal' DIC set up. Sometimes higher contrast is desirable even though it lacks some of the details of a normal DIC set up. Olympus and Nikon actually cater to this idea and offer low and high contrast varieties of prisms on their newer models.