DIY epi-DIC

[Wes]

I had the idea to build an epi-DIC setup with components I currently have namely a IIIRS fluorescent condenser, a couple of polarizers, a 50:50 mirror, a 16/0,32 epi-Plan objective and a 16/0,32 Plan DIC slider for regular transmitted DIC. In epi-DIC a single DIC prism is used to shear and then recombine the surface reflected O and E beams which then interfere to produce the contrast.




This is how it looks.




And I used this aluminum element as a test object.




These are some surface defects with the DIC shearing axis positioned diagonally running from top-right to bottom left (/).




Same frame but with a wave plate added. The color can be altered by translating the DIC prism.




And these are the very same defects but rotated 90 degrees relative to the previous two images. The tiny marks previously not quite visible are now very obvious.




Again we can introduce color contrast by adding the quartz wave plate.




And just for reference I've taken out the DIC slider just to illustrate what the corresponding epi-Pol image would look like.


Any suggestions for interesting specimens are welcome. I remember a while ago folks were discussing silicon chip dies and someone offered to mail some. Any idea where I could get some of these?

BR
Wes

[PeteM]

Well done, Wes.

It seems to me that it might be able to prepare many biological specimens for epi DIC as well. Slice 'em very thin, stablize without a cover slip, maybe even a combination of reflected and transmitted light?

[Wes]

Well done, Wes.

It seems to me that it might be able to prepare many biological specimens for epi DIC as well. Slice 'em very thin, stablize without a cover slip, maybe even a combination of reflected and transmitted light?

Thanks Pete. Maybe teeth, bones and shells would light up well with this technique. What type of biological specimens do you have in mind?

[MicroBob]

Hi Wes,
interesting Idea! Is this a normal DIC "new" slider that you place in the slot in the tube head?

I have parts of a epi DIC system:
prism for 4:1 and 8:1 Pol objective
16:1 Pol objective
Prism for 40:1 objective, heavily delaminated

I haven't read a lot about this and also I'm not sure what precisely to expect from epi DIC.
I thought it is used for the detection of fine surface details.

Suitable subjects: Wear on all kinds of things that is practically invisible for the naked eye. Like credit cards, fishing lines, windscreen wipers, glass corrosion on longer stored slide packages, cutlery, microscope eyepiece eye lenses, contact surfaces of SD cards, frozen parts, ice crystals.

I also have one epi phase objective, quite a rare thing. But I havent spent energy into bringing it into use.

Bob

[PeteM]

Well done, Wes.

It seems to me that it might be able to prepare many biological specimens for epi DIC as well. Slice 'em very thin, stablize without a cover slip, maybe even a combination of reflected and transmitted light?

Thanks Pete. Maybe teeth, bones and shells would light up well with this technique. What type of biological specimens do you have in mind?

Not having tried this I could be way off. But it seems that anything very thinly cut or smeared that might normally be viewed with transmitted light could be place on a reflective background (white, silvered, etc.) so some light shines not to just back from the top but through the specimen and back. The trick, without a cover glass, would be to keep the subject thin and flat. So, maybe roll it on with some sort of medium, dryer, or adhesive to have it end up as sort of a semi-transparent coat of "paint."

It might also be interesting to have mostly reflected light, but also some transmitted - perhaps with a third polarizer (on the field diaphragm) in phase??

Just a thought - but if it worked it could open up a whole 'nuther cool imaging method?

[Wes]

Hi Wes,
interesting Idea! Is this a normal DIC "new" slider that you place in the slot in the tube head?

Yes, you are correct its the 16x Plan DIC slider for the new DIC system.

I have parts of a epi DIC system:
prism for 4:1 and 8:1 Pol objective
16:1 Pol objective
Prism for 40:1 objective, heavily delaminated

If these come with an RMS thread you can give it a try using your fluorescent condenser to which you must add a 50:50 mirror (but a coverslip may work too).

I also have one epi phase objective, quite a rare thing. But I havent spent energy into bringing it into use.

Interesting, what purpose would this objective serve? I've never seen one like that.

Well done, Wes.

It seems to me that it might be able to prepare many biological specimens for epi DIC as well. Slice 'em very thin, stablize without a cover slip, maybe even a combination of reflected and transmitted light?

Thanks Pete. Maybe teeth, bones and shells would light up well with this technique. What type of biological specimens do you have in mind?

But it seems that anything very thinly cut or smeared that might normally be viewed with transmitted light could be place on a reflective background (white, silvered, etc.) so some light shines not to just back from the top but through the specimen and back.

I see now. This would cause a phase shift and may produce very nice contrast. For example erythrocytes smeared on an glass slide electrosputtered with a tin metalic layer.

[MicroBob]

I have an epi condenser for single objectives mounted in a "monkel". Reflectors "D" and "H-Pl" too. I'm not quite shure about the objective lenghts here as Zeiss had more than one on their epi stuff. The two epi DIC prisms look as if they were made for objectives of different lenght and design.

Epi phase was shortly used before epi DIC became available.

[Scarodactyl]

I'm impressed with your results! That looks to be working magnificently.

[Wes]

I have an epi condenser for single objectives mounted in a "monkel". Reflectors "D" and "H-Pl" too. I'm not quite shure about the objective lenghts here as Zeiss had more than one on their epi stuff. The two epi DIC prisms look as if they were made for objectives of different lenght and design.

Epi phase was shortly used before epi DIC became available.

The H-Pl reflector should work fine for epi-DIC.

I'm impressed with your results! That looks to be working magnificently.

Thanks. Below is a hologram image I took with my phone. The gradient was produced by flipping the prism upside down. Overall metalic and otherwise reflective surfaces work really well. Plastic, paper, wood etc not so much.