Unless I am much mistaken, all that is required for phase contrast is

a) a suitable phase-contrast objective and

b) a suitable phase-contrast annulus in focus in the condenser.

A telescope to see and focus the annulus can be extremely helpful.

Getting the annulus in the right position in a condenser not designed for phase

contrast can present a challenge.

On Sun, Jul 11, 2021 at 10:29 PM keith stout <keithstout@...> wrote:

I have a vintage Leitz BK scope, 1941 model. It is a bright field scope. It uses an external light source on a mirror located below the condenser to send light through the condenser. I wonder if it is possible to do phase contrast viewing with it. I see phase contrast objectives for sale. I see opaque phase contrast filters that fit in the illumination path. Is this all that is needed to create phase contrast lighting?

Or does this task require so much engineering that it is best to buy a phase contrast scope?

Thanks for any input. Keith

--

73 de

Mike Andrews W5EGO

Hi Keith and Mike,

As has been discussed sometimes in the Microscope forum and demonstrated in online article(s), ring LEDs may now conveniently substitute the phase contrast condenser

Here is an example of its applications, but somewhere there was an article for hobbyists:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4277858/pdf/jmi0257-0008.pdf

Regards,

Ricardo

 

Em 12/07/2021 13:31, Mike Andrews escreveu:

Unless I am much mistaken, all that is required for phase contrast is

a) a suitable phase-contrast objective and

b) a suitable phase-contrast annulus in focus in the condenser.

A telescope to see and focus the annulus can be extremely helpful.

Getting the annulus in the right position in a condenser not designed for phase

contrast can present a challenge.

On Sun, Jul 11, 2021 at 10:29 PM keith stout <keithstout@...> wrote:

I have a vintage Leitz BK scope, 1941 model. It is a bright field scope. It uses an external light source on a mirror located below the condenser to send light through the condenser. I wonder if it is possible to do phase contrast viewing with it. I see phase contrast objectives for sale. I see opaque phase contrast filters that fit in the illumination path. Is this all that is needed to create phase contrast lighting?

Or does this task require so much engineering that it is best to buy a phase contrast scope?

Thanks for any input. Keith

--

73 de

Mike Andrews W5EGO