Microscopy: Abbe Diffraction (Kurt Thorn)

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This lecture/lab describes the famous experiments of Ernst Abbe which showed how diffraction of light by a specimen (and interference with the illuminating light) gives rise to an image and how collection of diffracted light defines the resolution of the microscope. These concepts are demonstrated by using a diffraction grating as a specimen and visualizing and comparing the diffraction pattern in the back focal plane as well as the image in the image plane.

[@stuartgreene5010]

Abbe would have loved this video. I've watched it 3 times over the past few years. Nothing has ever made these concepts more clear to me. I come back here to be inspired and re-educated. A million thanks!

[@vikramjoshi3452]

This was an excellent demonstration! With the grid that you showed toward the end of this video, it also helped me understand how X-ray diffraction works - I thought I knew how it did till I saw this video :)

[@wenwuxu6300]

What an amazing demonstration!!! Thank you for sharing.

[@ishitvvats2044]

Unreal. amazing demonstration.

[@Markkb24]

This is so good! If I were to see this video 15 years ago I'd pick physics instead of Biology

[@shrawan12321]

awesome explanation and an ever better microscope set up

[@kunlin579]

very nice demonstration!

[@f.k.6151]

Great lecture, thank you.

[@monenehmoneneh9561]

perfect, very intuitive

[@luisalfredoixquiacmendez8494]

Excellent lecture!

[@rashmeetkaur5756]

Beautifully explained ❤️

[@tommac19]

Really good, clear video. Thanks!

[@matricious]

Greatly explained, thanks a LOT!

[@victorhbs17]

Thank you Sir, excellent video.

[@onimabisht1393]

Amazing tutorial!! Thanks a lott!!

[@shashankshekhar9173]

great video...keep up the nice work...

[@mp3lwgm]

What is on the memorial is Wavelength/(2 n sin(Alpha)), not Wavelength/(n sin(Alpha)). So what happened to the factor of 2?

[@gokulc8621]

6:08 he explains it

[@dribblersmy]

good explanation, thank you!

[@jiayou5731]

Great explanation for Fourier Optics. But I was expecting a little more on numerical aperture.

[@leif1075]

Not really..why would vertical grating produce horizontal pattern and not vertical??

[@nedialko7477]

"The LED here is in the back focal plane of the condenser" ? isnt't it : "The LED here is in the back focal plane of the collector lens" ?

[@leif1075]

Why would vertical grating create horizontal pattern and vice versa..there's no reason to predict or suspect that and no explanation given?? Why woukdnt you use see apattern of light and dark stripes?? That makes more sense!

[@zyllianas]

how nice is it!

[@farazkarsha6066]

BIG like

[@cipndale]

For those of you who are a bit slow like me this here is a video much better made at a slower pase: kzbin.info/www/bejne/bGHCm5qQqd6FbLc

[@madireddydayananda2269]

first of all please tel in brief way wts the theory....and a animation..so that..people can understand in a easy way.

[@Mr_ToR]

+Madireddy Dayananda dude, this is part of a series. did you watch the previous 13 videos? if you can not understand why he limits the spectrum using a green filter or when he says field lens or parallel beams or condenser or focal plane or lambda or aperture, you should have some idea of those first. This is an incredibly valuable series. It is free because a foundation paid for it to be free. This is not your i-can-not-watch-a-subject-more-than-5-minutes type of iGreneration video which you can find many of. If you watch the series, you can make yourself the simple explanation video that you want. Also, "first of all", please learn to write properly.

[@kaleemullah8142]

This lecture can be improved.

[@cipndale]

If you don't say where can it be improved it's like saying nothing.