How does a COL filter look like?

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Raul
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How does a COL filter look like?

#1 Post by Raul » Thu Apr 14, 2016 11:31 pm

Exactly as the title says, can someone photograph his filter or find/make a diagram on how a COL filter should look like please?



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Raul

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zzffnn
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Re: How does a COL filter look like?

#2 Post by zzffnn » Fri Apr 15, 2016 12:06 am

They look like slightly under-sized darkfield filter. Examples here (see Figures 4, 7, 10, 16 and 24):
http://www.microscopy-uk.org.uk/mag/ind ... c-col.html

You can DIY, though I bought mine from this eBay seller (mine look exactly like the listing):
http://m.ebay.com/itm/271373182738?_mwBanner=1

You can even combine several filters together to fine tune it.

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Raul
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Re: How does a COL filter look like?

#3 Post by Raul » Fri Apr 15, 2016 12:04 pm

Thank you zzffnn, that information is most helpful.

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zzffnn
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Re: How does a COL filter look like?

#4 Post by zzffnn » Fri Apr 15, 2016 1:53 pm

There is more:

Http://www.microscopy-uk.org.uk/mag/ind ... phase.html

I suggest reading all of those articles.

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charlie
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Re: How does a COL filter look like?

#5 Post by charlie » Sat Apr 16, 2016 5:09 pm

zzffnn wrote:There is more:

Http://www.microscopy-uk.org.uk/mag/ind ... phase.html

I suggest reading all of those articles.
Regarding making a phase telescope, I concluded that unless one owns oculars to use in making one, there is no savings over just buying a phase telescope,

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Re: How does a COL filter look like?

#6 Post by zzffnn » Sat Apr 16, 2016 5:58 pm

Sorry, I gave the wrong link.

Here it is: http://www.microscopy-uk.org.uk/index.html

Click on "library", " Techniques - lighting" then "oblique and COL". You will find quite a few articles to read on the topic.

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Raul
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Re: How does a COL filter look like?

#7 Post by Raul » Sat Apr 16, 2016 8:25 pm

Thank you zzffnn for the link.
charlie I do not intend to make a phase telescope yet, but thank you for the tip.

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