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Closterium

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#1 polaroidia

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Posted 30 April 2019 - 06:04 PM

Here's an image I made yesterday of Closterium.

From a water sample of a small stream in a local forest preserve.

50ish year old Swift SRL phase contrast microscope. 160x

Canon EOS Rebel T1i. Image cropped.

Attached Thumbnails

  • Closterium post.jpg

Edited by polaroidia, 30 April 2019 - 06:05 PM.

  • terraclarke, JMKarian, bluesteel and 5 others like this

#2 TOMDEY

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Posted 30 April 2019 - 06:46 PM

Wow! That illumination is nice. It is dark-field of from the side or?   Tom



#3 polaroidia

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Posted 30 April 2019 - 07:06 PM

It is phase contrast. A special set of objectives matched to "rings" below the condenser. It's what gives it that "glow".

It mainly works for transparent or semi-transparent specimens. The main illumination is still from below.



#4 wrnchhead

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Posted 30 April 2019 - 08:31 PM

Really really cool

#5 mashirts

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Posted 30 April 2019 - 08:38 PM

Beautiful. So much color.

#6 happylimpet

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Posted 01 May 2019 - 01:33 PM

It is phase contrast. A special set of objectives matched to "rings" below the condenser. It's what gives it that "glow".

It mainly works for transparent or semi-transparent specimens. The main illumination is still from below.

So I spent a good half hour reading about phase contrast microscopy! Is it possible to modify a conventional microscope to phase contrast, for someone with decent optical/telescope/planetary imaging type skills?



#7 stevie

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Posted 04 May 2019 - 05:55 AM

A phase contrast setup usually comes as a set which consists of a condeser lens  with blocking rings (think of it as a filterwheel) and matched objectives .

Aonther way to go around this is with Oblique Illumination , where you block a part the light entering the condeser lens .



#8 Microscopy

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Posted 22 May 2019 - 08:24 AM

Splendid image, polaroidia. Very nice!

 

So I spent a good half hour reading about phase contrast microscopy! Is it possible to modify a conventional microscope to phase contrast, for someone with decent optical/telescope/planetary imaging type skills?

It's possible to make the phase plates yourself (they're usually placed between the aperture diaphragm and the lens system of the condenser in a classic Zernike design, but placing them underneath the condenser's iris will work as well), but you still need the phase objectives.

Well actualy you need the objectives first, to measure the corresponding phase plates.

 

Phase objectives can be used for regular brightfield, but not the other way around.

 

Most brands of microscopes at the time had one or a few models for general use, and as an option for those one or a few phase plates that could slide into the condenser, f.e. providing phase contrast for the 40x objective, which was then a phase objective. That was the case f.e. for the, at the time very popular Olympus CH and CH2 stands but it was the case as well for some stands from far lesser known brands such as Kyowa (Japan) or Will/Hund (Germany) among many others.



#9 Billy Bl.

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Posted 02 June 2019 - 07:07 AM

Have you ever tried interference contrast? Phase contrast is pretty, but interference contrast is cool.



#10 NGC704

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Posted 21 June 2019 - 08:30 PM

Interference contrast, if you refer to differential interference contrast, or DIC, is certainly super cool but also super expensive (well ... all things are relative but it's generally considered to be fairly obscene). I know, I have two DIC stands, one upright and one inverted.

 

Phase contrast, on the other hand, is exceedingly nice and far more affordable. Generally speaking, one obtains a phase contrast microscope, or buys a phase contrast set for use with an existing stand which includes phase objective lenses and matching phase annuli  in a rotating carousel condenser or some sort of slider arrangement. It can be done DIY, but only for the ambitious.

 

See my Flickr below for a few DIC images...


Edited by NGC704, 21 June 2019 - 08:31 PM.



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