Astronomy 5-Position Filter Wheel into a DIY condenser filter holder

[daruosha]

Hi.

Have you seen these 5 position filter holder?

https://www.amazon.com/Astromania-Multi ... B0140UA9F6

Their mian purpose is to change/swap filters for astronomy photography, however I wondered is it possible to make a DIY condenser filter holder out of them? Something like phase contrast turret condensers.

Anyone tried them? Eager to hear your opinions.

[MicroBob]

Hi Daruosh,
they write that the filters are 5,1cm diameter (probably close but not exactly). So the whole filter wheel has quite a big diameter and would protrude a lot from under the stage.
When you look here: http://www.mikrohamburg.de/Tips/Technik ... 8.2019.pdf
a phase condenser is quite an impressive piece of fine mechanics. To build something with the same function from the filter wheel is probably not possible.

If you want to use phase contrast but have no condenser you coud build a phase annulli (I could describe this in more detail) fitting to your objective. On my "Biolamini" folding microscope with LOMO Biolam components I used such an annulli in the filter tray with good results.

Bob

[daruosha]

Hey Bob, it is always nice reading your comments.

They have 1.25" version as well. I have a turret condenser. Today i felt a bit down and went to an astronomy shop to cheer myself up, Saw this piece and it resembled me a turret condenser. It clicks on each rotation/stop., but no centering mechanism , which is fine for Rheinberg illumination. I thought if can make a turret condenser out of it, i could use it on other microscope for COL illumination and/or Rheinberg/Darkfield illumination. Because why not?

I'm sure you're speaking from experience and there are some difficulties.

[daruosha]

BTW, i read the linked PDF.. That condenser is a serious work of engineering Why all the best stuff are made in Germany?

[MicroBob]

For COL it is good to a able to use a center stop of maximum diameter and center it well. I did this with a transparent plastic disc, a turned central hub and punched out discs with central hole. The plastic disc had a bit of clearance in the holder and I nudged it in optimal position. This would be difficult in a turret condenser. For Rheinberg it will work very well. For dark field the centering of the central stop is important and also the position in the light path. For transmitted fluorescence it would work too. For some DIY-DIC like contrast methods it will work too. This would probabl the best use for the ruffet filter holder.

The Zeiss condenser is frome a time when engineers ran the german companies and the question was :"Can we make it better?" and not: "Can we make this cheap while retaining basic functionallity?". Especially Zeiss somtimes really overdid it and many older Zeiss designs go much beyond the demands of many of today customers. For the user of affordable old microscopes this is nice, such solid designs are rarely found today.

[daruosha]

The question is how to attach condenser optics (or a complete abbe condenser) on top of the wheel firmly and reliably. The filters cannot be to far from the bottom of the condenser too.
I think buying a used turret condenser is much easier

Question: In case of buying a used turret condenser, is it possible to replace the phase annulus with an another filter? I know Olympus and Nikon have generic turret condensers with customizable filters, but do other cheap turret condensers allow user to replace the filters?

I don't dare to open my own turret condenser. I accidentally disassembled its diaphragm aperture and took me days to re-assemble it again. It was a nightmare. I can fix many condenser aperture now though

[WhyMe]

I don't dare to open my own turret condenser. I accidentally disassembled its diaphragm aperture and took me days to re-assemble it again. It was a nightmare. I can fix many condenser aperture now though

Boy do I understand! I decided to clean my microscope up a bit. Took the illuminator apart and cleaned it, then took the condenser and apart and all the diaphragm leaves fell out! Two hours later I had a working condenser again!

[daruosha]

I don't dare to open my own turret condenser. I accidentally disassembled its diaphragm aperture and took me days to re-assemble it again. It was a nightmare. I can fix many condenser aperture now though

Boy do I understand! I decided to clean my microscope up a bit. Took the illuminator apart and cleaned it, then took the condenser and apart and all the diaphragm leaves fell out! Two hours later I had a working condenser again!

I consider you to be a very mechanically capable person. It took me no less than 3 days of constant try and error to figure out the proper arrangement of the diaphragm blades (they were in a spring loaded position and once I opened the housing, they jumped and flied out. Reattaching the spring took another day. Dexterity ans patient was the key. Imagine the stress too (I paid nearly 1000USD for the kit just a day before the diaster)

But once you know how to do it, it becames very easy to do it again

[WhyMe]

I consider you to be a very mechanically capable person. It took me no less than 3 days of constant try and error to figure out the proper arrangement of the diaphragm blades (they were in a spring loaded position and once I opened the housing, they jumped and flied out. Reattaching the spring took another day. Dexterity ans patient was the key. Imagine the stress too (I paid nearly 1000USD for the kit just a day before the diaster)

But once you know how to do it, it becames very easy to do it again

My father taught me a lot in my younger years. Now the internet teaches and helps me!

[MicroBob]

It was a nightmare.

The last couple of blades are the worst to reinstall and some diaphragms are really nasty. The second one is easier...