B A quartet of epi-illumination methods

[Andy Resnick]

TL;DR Summary

I finally obtained a set of epi-phase microscope objectives (Zeiss)

Well, it took almost 20 years (!!!), but I finally obtained a set of epi-phase microscope objectives (Zeiss). The principles of epi-phase contrast is nearly identical to transillumination phase contrast, but the phase ring is a 1/8 wave retarder rather than a 1/4 wave retarder (because with epi-illumination, the light passes through the ring twice). This method was popular only for a very short period of time before epi-DIC (differential interference contrast) became widely available. So, not only are epi-Ph lenses impossible to find, but they are cheap because nobody wants them :)

Here are 4 images of a razorblade comparing the different epi illumination methods, all using 40x lenses. In order: brightfield, phase contrast, DIC, and darkfield:

While epi-phase looks a bit like epi-darkfield, the biggest difference is the light throughput- 1/30 s shutter (phase) instead of 5 s (darkfield).

Success! I feel like Captain Ahab, if he had finally caught Moby Dick. But I guess that would moot the point of the story....

 

[sophiecentaur]

TL;DR Summary: I finally obtained a set of epi-phase microscope objectives (Zeiss)

but they are cheap because nobody wants them :)

II that 'cheap' like a second hand Maserati or cheap cheap? Captain Ahab went overboard , remember so be careful.

I guess they need all you existing gear to do their stuff. I'm pleased for you and the images are interesting. Could you do labels?

 

[Andy Resnick]

II that 'cheap' like a second hand Maserati or cheap cheap? Captain Ahab went overboard , remember so be careful.

I guess they need all you existing gear to do their stuff. I'm pleased for you and the images are interesting. Could you do labels?

cheap-cheap: Including shipping from Europe, the cost was $US 120 for all three, all in new condition, likely never used :)

Thanks, re: the images. More to come as I improve my technique!