Re DIY polarizing filters

[wmodavis]

In another thread it was suggested to use a camera screw on polarizing filter such as the HOYA that was shown.
My question (s):

I believe those type filters contain two polarized filters in a rotatable frame and thus to use on a microscope must be separated. Is that true?

If so has anyone had experience dissecting the camera polarizer filters that could offer advice on how to do it with minimal destruction?

Thanks for any input.

[gekko]

I don't think the usual camera polarizing filter has two filters. The filter is in a frame that rotates relative to the threaded part that goes on the lens, which then allows the filter to be rotated relative to the lens/camera to obtain the desired effect. One point to remember is that most camera polarizing filters sold nowadays are circular polarizers (often called "CPL"). What you want is a linear polarizer (both are available inexpensively on ebay). I hope this helps.

[Charles]

From what I understand there are two types of camera polarizers...circular and linear and both can be used. The circular does have two sheets of film, a polarizer and a 1/4 wave plate. If the circular polarizer is used in one direction where the wave plate is down and polarizer up (where the light hits the wave plate first), you only get polarizing effects. If the circular polarizer is used with the wave plate up (where the light hits the polarizer first), you also get polarizing effects but with the addition of the 1/4 wave plate effects which adds some color.

[gekko]

What Charles said above is right. The reason why I suggested linear polarizers is that I think they provide better extinction. People add a piece of cellophane or other plastic as a phase retarder, although both JimT and seb Vasselle use basically circular polarizers and get excellent images.

[JimT]

Let me refer you to an easy and "Free" way to add polarization to your scope. Check out the article in the Microbehunter magazine issue 49 below:

http://www.microbehunter.com/microbehun ... -issue-49/

JimT

[wmodavis]

Let me refer you to an easy and "Free" way to add polarization to your scope. Check out the article in the Microbehunter magazine issue 49 below:

http://www.microbehunter.com/microbehun ... -issue-49/

JimT

Thanks Jim for that link. Just read it and it answered another question I posted about whether LED lighting works with polarizing filters. And it seems the article's thrust fits well within my DIY nature. Hoping to be able to be viewing soon.
Bill

[wmodavis]

Was prompted to snoop in the catacombs in the basement caverns below and in an old camera case from bygone years I found two camera lense polerizers. Walla! Now all I need is a microscope and some years of practice.

[billbillt]

It won't take you years of practice.. You know the practice and theory of polarization... The rest is simple...

BillT

[Interference]

Most camera pols don't go very extinct and do have a colour cast, often blue.
But I see one can buy "Variable neutral density" filters which must be a pair. Perhaps they're better.