Can anyone ID this darkfield condenser please?

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mrsonchus
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Can anyone ID this darkfield condenser please?

#1 Post by mrsonchus » Tue Mar 14, 2017 8:37 pm

Hi all, I'm having a 'muck-out' of some of my lab drawer space and came across this condenser in with other bits and pieces. It looks like a darkfield condenser as it has the slider with 3 darkfield masks along it.
The whole thing is heavily constructed and all-metal. It has a fitting diameter of 37/38mm (can't be precise without proper measurement) and the slider that goes into the condenser is 28mm wide, and fits into the slot above my Orthoplan's nosepiece perfectly - although of course it's nothing to do with the Orthoplan, just fits the slot....

A few pictures, I'd like to know more about it, if anyone can shed any light upon it's identity - it has no markings....

Image

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Image

Image

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Image

I must have acquired it back when I first started without knowing really what it was - I'm still not sure! :D

Anyone have any idea what make it is and exactly what it is - a darkfield condenser?

Thanks chaps

John B :)
Last edited by mrsonchus on Wed Mar 15, 2017 5:47 pm, edited 2 times in total.
John B

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Yann E.
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Re: Can anyone ID this darkfield condenser please?

#2 Post by Yann E. » Tue Mar 14, 2017 9:06 pm

Hi John,

this is more likely to be a phase condenser. The finish is somewhat reminiscent of some Gillett & Sibert products but their phase condensers were of the turret type AFAIK, not slider type so I'm at a loss here...

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Re: Can anyone ID this darkfield condenser please?

#3 Post by zzffnn » Tue Mar 14, 2017 9:08 pm

John B,

It is more likely a phase condenser. I cannot ID it though. If those phase annuli fit your phase objectives, then they will work. Otherwise, they can be used a COL or darkfield stops.

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mrsonchus
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Re: Can anyone ID this darkfield condenser please?

#4 Post by mrsonchus » Tue Mar 14, 2017 9:10 pm

Ah - yes they could be phase rings couldn't they? I'd like to know what it is so I can decide if I can use it sometime or just sell it. Thanks Yann. :)
John B

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mrsonchus
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Re: Can anyone ID this darkfield condenser please?

#5 Post by mrsonchus » Tue Mar 14, 2017 9:15 pm

zzffnn wrote:John B,

It is more likely a phase condenser. I cannot ID it though. If those phase annuli fit your phase objectives, then they will work. Otherwise, they can be used a COL or darkfield stops.
Hmm, sounds interesting - I'd love to find out more about this....

Thanks zz' :)
John B

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Re: Can anyone ID this darkfield condenser please?

#6 Post by zzffnn » Tue Mar 14, 2017 9:29 pm

You can offset them for oblique too, the widest ring is likely useful for 40x objective oblique, the medium one will probably work well for 10x-20x. If the condenser and objective combo is not well corrected though, you may see some CA in oblique.

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Re: Can anyone ID this darkfield condenser please?

#7 Post by apochronaut » Wed Mar 15, 2017 4:55 pm

I'm not seeing any pictures. Just the words image , 7 times.

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mrsonchus
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Re: Can anyone ID this darkfield condenser please?

#8 Post by mrsonchus » Wed Mar 15, 2017 5:48 pm

apochronaut wrote:I'm not seeing any pictures. Just the words image , 7 times.

Urk! Try now - I think I did something wrong.... should be OK now. :)
John B

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Re: Can anyone ID this darkfield condenser please?

#9 Post by apochronaut » Wed Mar 15, 2017 8:45 pm

I would think you might be able to adapt that to work on your stand, John. Just having that slide carrier in the substage, opens up some diy possibilities for COL, maybe phase if you can find some objectives and COL/DF, possibly, which has great possibilities for imaging very transparent subjects, not dissimilarly to DIC. Your 100 watt illuminator is a guaranteed necessity for that , so you are well positioned to use that as a potential future accessory, to expand your Orthoplan's system.

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mrsonchus
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Re: Can anyone ID this darkfield condenser please?

#10 Post by mrsonchus » Wed Mar 15, 2017 9:03 pm

apochronaut wrote:I would think you might be able to adapt that to work on your stand, John. Just having that slide carrier in the substage, opens up some diy possibilities for COL, maybe phase if you can find some objectives and COL/DF, possibly, which has great possibilities for imaging very transparent subjects, not dissimilarly to DIC. Your 100 watt illuminator is a guaranteed necessity for that , so you are well positioned to use that as a potential future accessory, to expand your Orthoplan's system.
Now that sounds interesting - I'll hang onto this condenser - it's doing now harm in it's box after all - thanks Apo ' - I'll ask you more about this in a while if that's OK. :)
John B

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Re: Can anyone ID this darkfield condenser please?

#11 Post by lorez » Wed Mar 15, 2017 10:45 pm

Here is the B&L iteration of what you have. There are three phase masks and one darkfield. This component was part of the Galen 2 model which was made by Kyowa and current in the early to mid 1980s. The masks were pre centered in the sliders and did not need to be adjusted. In over 30 years of service I never saw one go out of alignment.
B&L-Phase-Condenser.jpg
B&L-Phase-Condenser.jpg (143.23 KiB) Viewed 5720 times
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