Daylight Köhler Illumination and the Fourierfeldblende

Here I describe a module that allows the PUMA Köhler illuminator to run on daylight. I also show how you can project structured apertures on the Fourier plane of the condenser via the Köhler illuminator i.e. the principle of the Fourierfeldblende. This video also gives a teaser intro into the wonderful world of Fourier optics and the diffraction theory of image formation in the microscope but these topics must wait future videos for detailed explanation.
CONTENTS
========
00:00 Intro
00:53 Fitting the daylight Köhler adaptor
02:28 Types of light that can be used
06:58 The Fourierfeldblende
12:20 Demonstration of projected structured light
21:01 Conclusions
SUPPORT PUMA
============
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1. Become a Patron: / pumamicroscope
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PARTS AND TOOLS
===============
For the latest details see the 'Bill_of_Materials' on the PUMA GitHub page ( github.com/TadPath/PUMA ).
3D Printed Models Updated for this Video
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Dominus:
Daylight_Kohler_adaptor.stl - new. This is in FreeCAD file 'Dominus_part1' in the 'Mirror_Illumination' group of models.
Non-Printed Parts and Tools
---------------------------
No changes were introduced with this video.
LINKS TO REFERENCED VIDEOS
==========================
First Köhler video:
• Köhler Illumination - ...
How To Build Foundation Scope:
• How to Build a PUMA Fo...
First condenser video:
• The Abbe Condenser wit...
OTHER LIMKS
===========
PARD Capture software:
github.com/TadPath/PARDUS/tre...
PUMA Köhler Illuminator Specs document:
github.com/TadPath/PUMA/tree/...
FOR FURTHER INFORMATION
=======================
1. Open access write-up about PUMA on the FreeCAD blog:
blog.freecad.org/2023/02/13/a...
2. The official PUMA GitHub page where you can download the specs and source files to build or customise your own PUMA system:
github.com/TadPath/PUMA
3. The scientific peer reviewed publication on PUMA that was published in 2021 in the Journal of Microscopy (a journal of the Royal Microscopical Society) available here:
pubmed.ncbi.nlm.nih.gov/34151...
onlinelibrary.wiley.com/doi/1...
Thanks for your interest in the PUMA microscope system.
PJT 01/03/23

[@PUMAMicroscope]

There is an update to this video here: ruclips.net/video/B0DOYpfdsyg/видео.html
To learn about Köhler illumination in detail see my first video: ruclips.net/video/XEE-el7vC5k/видео.html and my video about conjugate planes: ruclips.net/video/Ai86SMBJqr8/видео.html

[@src7983]

A very good video of Köhler lighting! Also, the opening sound has changed.👀

[@PUMAMicroscope]

Thanks.

[@user-jz4kx1no9i]

I have been trying to assemble Koehler optics for microscopes that didn't have it originally. I was confused about the fourier plane in the illuminator. This plus your prior Koehler video made it clear. Thanks! I have not seen anyone else discussing Koehler as a 'special case' of modulation in this plane. I imagine a future in which every microscope has structured illumination, plus a camera and something like Pardus. And a few of us will say, "I remember the dark ages, before Fourierfeldblende."

[@PUMAMicroscope]

Thank you - and thanks for your support!
I hope to be doing quite a bit more on Fourier optics and Abbe diffraction theory in future videos so hopefully you will enjoy those also - but first I need to do a few computer programming videos so I can bring viewers along with me on the journey.

[@beautifulsmall]

Ive been an amateur microscopist for 40 years , the use of the microscope has always amazed me and its huge diversity optical concoctions. phase contrast, epi, UV. I recently used an optical microscope capable of x6500 I thought oil x100 was the limit. . I didnt try that setting but I wonder if it used reverse convolution to compute the surface. It was camera based. This 3D print looks amazing. You have clearly dedicated serious thought and have the results worthy. Regards.

[@PUMAMicroscope]

Thanks. I intend to make some videos on deconvolution in microscopy at some point. However, even with deconvolution it is hard to push the resolution beyond what you can get with a high quality x100 oil objective (without using special fluorescence techniques). These super-high mag scopes just make small things easier to see without straining your eyes - which is good - but they don't really push the resolution 'limit'. You get essentially 'empty mag' as this video demonstrates: ruclips.net/video/2sWF_NHPzn8/видео.html