Crossed Polarizers verses DIC darkfield

Walter Piorkowski · Post by **Walter Piorkowski** » Wed Nov 29, 2006 11:36 am

Crossed Polarizers verses DIC darkfield

Top image:
Nikon Type S with DIC attachment
DIC in darkfield setting – Nikon 10X DLLF objective
Olympus 2.5X projection eyepiece
Canon 10D

Lower image:
Leitz Ortholux in brightfield
Crossed Polarizers - Leitz 12.5X objective .
10X Periplan GF projection eyepiece plus 1/3X relay lens
Canon 10D

I have always enjoyed looking at transparent crystals with crossed polarizers to show the exquisite colors against the black background.

In a recent experiment with some magnesium fluorite crystals I tried viewing the sample with my Savart DIC unit tuned to its darkfield position. As DIC instruments work between polarizers I found that it produced a similar although not exact appearance as the true polarizing microscope. I have also darkened the field in Photoshop and sized the images to match for this comparison. The differences are subtle but interesting nonetheless.

Walt

Ken Ramos · Post by **Ken Ramos** » Thu Nov 30, 2006 3:34 am

Your getting too technical for me Walt

I am not up on DIC or Crossed Polarizers but another set of great images.

Walter Piorkowski · Post by **Walter Piorkowski** » Fri Dec 01, 2006 12:08 pm

Ken, If crossed polarizers means nothing to you, let me introduce you to a new way of enjoying your hobby. Get your hands on two of the polarizers sold for the front of camera lenses. You can get these very cheaply some times when camera stores are clearing out old stock. Place one somewhere under your microscopes condenser and the other temporally between your eye and your eyepieces. Rotating it will provide a change in the polarized light and when the field goes black you have crossed the two polarizers. You can never tell what subjects or features will respond to polarized light but even the muscles of large protozoa and insects will appear more distinctly and fibers are a real treat. Don’t deny yourself this pleasure any longer.

Walt

bernhardinho · Post by **bernhardinho** » Fri Dec 01, 2006 3:26 pm

Walter Piorkowski wrote:Ken, If crossed polarizers means nothing to you, let me introduce you to a new way of enjoying your hobby. Get your hands on two of the polarizers sold for the front of camera lenses.

Walt

Hi,

but make sure ther're for linear polarization. The other being circular pol won't work as nicely.

Bernhard