Darkfield for AO 570

Here you can discuss different microscopic techniques and illumination methods, such as Brightfield, Darkfield, Phase Contrast, DIC, Oblique illumination, etc.
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jb89
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Darkfield for AO 570

#1 Post by jb89 » Thu Nov 14, 2019 4:35 pm

Just got my AO 570 and it's great, I'd be really interested in setting it up for darkfield, i just don't know what the options are.

Are there existing AO accessories for this or is it a DIY thing?

apochronaut
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Re: Darkfield for AO 570

#2 Post by apochronaut » Thu Nov 14, 2019 6:33 pm

Since you have a glass stage plate, DF is possible but I don't know of any off the shelf set up for the AO 570. Essentially you would need the 561S transillumination or substage base and a ring illuminator larger than the port in the base plate. The ring illuminator would need to have pretty high wattage. Most of the systems are 50 watts.

There may be some led ring illuminators out there that would give you enough lumens for a diy project.

jb89
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Re: Darkfield for AO 570

#3 Post by jb89 » Thu Nov 14, 2019 6:45 pm

I do have the 561S substage base, I'll have to see what I can find as far as high wattage illuminators, thanks!

Scarodactyl
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Re: Darkfield for AO 570

#4 Post by Scarodactyl » Thu Nov 14, 2019 7:15 pm

There are also darkfield baffles for stereo microscopes (meant for lower end gemological systems), though they need a lot of light to work well. I ended up with a ton of them so I can offer you a good deal on one if you want to try that.

eward1897
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Re: Darkfield for AO 570

#5 Post by eward1897 » Sun Dec 01, 2019 7:03 pm

I have an AO 570 stereo microscope. They good scopes. Good and varied illumination makes them work even better.

I use my led ringlight to produce darkfield. The ringlight is set led side up on the stage atop a piece of black paper (or black stage plate). I found a squat plastic cylinder with clear window that sits on top of the ringlight to hold the specimen. I put a black paper baffle in it to cut down on extra light. Works good for low power aquatic biology work.

You'll find several ways to get darkfield out of your scope. As a proof of concept you can turn off the other lights and illuminate from the side with a strong led flashlight.

My usual technique is a variation of David Walker's in Micscape at this link-
microscopy-uk.org.uk/mag/indexmag.html?http://www.microscopy-uk.org.uk/mag/art ... ht-DF.html

These aren't great photos, but they were taken with my AO 570. The view through the eyepieces is always better.

2014-5-4 hydra (14) stereozoom reduced.jpg
2014-5-4 hydra (14) stereozoom reduced.jpg (68.21 KiB) Viewed 2570 times
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2018-02-04 phantom midge larva stereozoom (5) reduced.jpg
2018-02-04 phantom midge larva stereozoom (5) reduced.jpg (30.3 KiB) Viewed 2570 times

apochronaut
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Re: Darkfield for AO 570

#6 Post by apochronaut » Sun Dec 01, 2019 11:51 pm

That works well. Pictures are pretty decent too.

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75RR
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Re: Darkfield for AO 570

#7 Post by 75RR » Sun Dec 08, 2019 7:12 pm

My usual technique is a variation of David Walker's in Micscape at this link-
http://www.microscopy-uk.org.uk/mag/ind ... ht-DF.html
Interesting technique! Thanks for the link to the article

Nice black in the second image
Zeiss Standard WL (somewhat fashion challenged) & Wild M8
Olympus E-P2 (Micro Four Thirds Camera)

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mrsonchus
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Re: Darkfield for AO 570

#8 Post by mrsonchus » Sun Dec 08, 2019 7:55 pm

Hi, agreed, those are nice images!

I used a black card circle to get DF on my stereo 'scope,
DF stereo disc (1).jpg
DF stereo disc (1).jpg (19.03 KiB) Viewed 2386 times
Image
Image
Image

same size as the base of the glass pot (an ex candle holder). Works surprisingly well.
John B

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75RR
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Re: Darkfield for AO 570

#9 Post by 75RR » Sun Dec 08, 2019 8:20 pm

Works surprisingly well.
Agree, very nice!
Zeiss Standard WL (somewhat fashion challenged) & Wild M8
Olympus E-P2 (Micro Four Thirds Camera)

Hobbyst46
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Re: Darkfield for AO 570

#10 Post by Hobbyst46 » Sun Dec 08, 2019 9:55 pm

mrsonchus wrote:
Sun Dec 08, 2019 7:55 pm
...I used a black card circle to get DF on my stereo 'scope,
same size as the base of the glass pot (an ex candle holder). Works surprisingly well.
Thanks for showing this trick !
Zeiss Standard GFL+Canon EOS-M10, Olympus VMZ stereo

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mrsonchus
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Re: Darkfield for AO 570

#11 Post by mrsonchus » Sun Dec 08, 2019 10:05 pm

Forgot to say also, the moss branch is in water, not quite covered, hence the blown highlights - complete immersion or none at all would improve this detail.
John B

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