"Special objective" for centering epi illuminators

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enricosavazzi
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"Special objective" for centering epi illuminators

Post by enricosavazzi »

I remember reading on one of the Olympus web pages that one can use a "special objective" designed for centering epi and epi-fluorescence microscope illuminators. The page did not discuss how this accessory works, nor its technical name, nor an Olympus model name or number.

I assume this is an accessory that temporarily replaces one objective and displays some sort of centering reticle/target which one can use to center the field and aperture stops of an epi illuminator. It probably also includes a mirror or prism. I don't know whether one needs an additional reticle/target placed in one of the illuminator filter slots, but the Olympus page did not mention this.
  • What is this accessory called?
    How does it work?
    Is eBay item 264008030066 this kind of tool, or something else? (The description says it is only for use with Nikon inverted scopes)
    What about eBay Item 152988679737?
    Is it really necessary, or is there another way to accurately center an epi illuminator?
--ES

JohnyM
Posts: 463
Joined: Tue Dec 24, 2013 7:02 am

Post by JohnyM »

Nikon calls it "Lamp centering tool", dont know about olympus.
It's plain and simple - a matte glass with some crosshairs / circles.
Linked ebay item is inverted only due to not being angled - would be hard to spot anything on upright microscope...
Second is exactly same, but with angled mirror for upright scope.
It's not necessary at all. There are many ways to center the lamp:
-Use uniform fluorescence target and center via eyepieces
-Use UV barrier and ND filter and center via phase telescope
-Unscrew one of objectives and place a sheet of paper / diffusion screen at parafocal lenght (or close enough - dont worry too much about it).

Image
https://www.microscopyu.com/tutorials/arclamp

pbraub
Posts: 79
Joined: Fri Feb 02, 2018 1:23 pm

Post by pbraub »

Hi,

I also found the centering procedure outlined in the olympus RFA manual produced sufficiently good results for me. Olympus advises the use of a centering target (U-CST) which I don't have and always replaced by a sheet of cardboard with a cross drawn on it or just by a plain sheet of paper/cardboard.

In short:
- center and focus the crosshair on the cardboard in a 10x objective
- turn the revolver to an empty position (without protective cap)
- minimize field diaphragm and maximize aperture diaphragm
- focus the arc of the lamp with the collector lens focus
- center the lamp with the centering knobs

https://www.google.com/url?sa=t&rct=j&q ... k0_aCO0xIQ

enricosavazzi
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Joined: Sat Nov 21, 2009 2:41 pm
Location: Borgholm, Sweden
Contact:

Post by enricosavazzi »

Thanks for the answers.

I will try the cardboard crosshairs target first. If it gives good results, no need to shell out money for a fancier solution.
--ES

Greenfields
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Location: Nottinghamshire, England

Post by Greenfields »

Leica have an online video demonstrating the use of a piece of card on the stage:

https://www.leica-microsystems.com/scie ... p-housing/

Henry
Feel free to edit my images.

Photomicro
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Re: "Special objective" for centering epi illumina

Post by Photomicro »

enricosavazzi wrote:I remember reading on one of the Olympus web pages that one can use a "special objective" designed for centering epi and epi-fluorescence microscope illuminators. The page did not discuss how this accessory works, nor its technical name, nor an Olympus model name or number.

I assume this is an accessory that temporarily replaces one objective and displays some sort of centering reticle/target which one can use to center the field and aperture stops of an epi illuminator. It probably also includes a mirror or prism. I don't know whether one needs an additional reticle/target placed in one of the illuminator filter slots, but the Olympus page did not mention this.
  • What is this accessory called?
    How does it work?
    Is eBay item 264008030066 this kind of tool, or something else? (The description says it is only for use with Nikon inverted scopes)
    What about eBay Item 152988679737?
    Is it really necessary, or is there another way to accurately center an epi illuminator?
I have the second one you list above, angled. You can have it for ten UK pounds plus postage from the UK if you wish Enrico. It would please me that someone can put it to use, as it is from a large collection of a deceased friend. Aldo, I have very much enjoyed reading on your website over the years.
regards, Mike.

Time flies like an arrow, fruit flies like bananas.

https://www.flickr.com/photos/66189529@N08/

enricosavazzi
Posts: 1294
Joined: Sat Nov 21, 2009 2:41 pm
Location: Borgholm, Sweden
Contact:

Re: "Special objective" for centering epi illumina

Post by enricosavazzi »

Photomicro wrote:I have the second one you list above, angled. You can have it for ten UK pounds plus postage from the UK if you wish Enrico. It would please me that someone can put it to use, as it is from a large collection of a deceased friend. Aldo, I have very much enjoyed reading on your website over the years.
Thanks Mike, see PM.
--ES

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