http://confocal-microscopy-list.275.s1.nabble.com/Numerical-aperture-and-spatial-resolution-tp7591293p7591334.html
I found the link between NA and PSF/Resolution pretty well illustrated in this video:
Unfortunately, at the present times, at least here in Madrid, most if not all university lectures are Teams sessions. So on-site demos are not a choice.
I also align with Zdenee's view. "Why does higher NA mean higher resolution?" is a question with no trivial answer for biologists. The demo of looking the diffraction orders at the BFP with a Bertrand lens, using objectives with different NA and gratings of different densities, worked best for me when I first learned about spatial resolution. Still, for a biology undergraduate is difficult to comprehend intuitively why capturing more diffraction orders means higher resolution.
> *****
> To join, leave or search the confocal microscopy listserv, go to:
>
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy> Post images on
http://www.imgur.com and include the link in your posting.
> *****
>
> Hi George and Javier,
>
> regarding aperture and resolution of DSLR (actually mirror-less) I put
> some photos together here:
>
https://drive.google.com/file/d/1vDYqDBPgapZYad3JahRm8R5W5Bkwu4T6> But, it will only work with some lenses (well, with most, but not in
> the full F-stop range), and only with some cameras (more pixels is
> better here, kind of an exception :-).
>
> Davide, the Evenett's video is great! Many demonstrations were quite
> surprising, and I have nothing to add to it (maybe a note, that the
> phase contrast method in all its simplicity still yielded Zernike a Nobel prize!).
> But even though one thought follows from another nicely, at the end if
> you ask your students "So why does higher NA mean higher resolution?"
> they'll say "Well, uhm..." It's not very likely they'll gain a deeper
> understanding of how all these concepts fit together.
>
> Good luck!
>
> zdenee
>
> On Sat, Sep 19, 2020 at 12:25 PM George McNamara
> <
[hidden email]>
> wrote:
>
>> *****
>> To join, leave or search the confocal microscopy listserv, go to:
>>
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy>> Post images on
http://www.imgur.com and include the link in your posting.
>> *****
>>
>> Hi Javier,
>>
>> I suggest you ask the class if they have any interest in taking
>> photos with their smartphone or DSLR camera, and if they do, bring in
>> a DSLR and tripod and computer/projector (if the room does not have
>> that already), explain f/stop and NA are inverse of each other, and
>> demonstrate NA (resolution, intensity, depth of field) on the class
>> by focusing on faces in the middle row. Wavelength: yes, you could
>> buy some filters for the camera lens (or deal with separating
>> channels in Photoshop, fiji ImageJ, etc), but probably better done on a microscope.
>>
>> George
>>
>> p.s. this post was inspired by a conversation yesterday -- Friday
>> happy hour -- with a colleague, Prof. Jim Potter, who told me about a
>> conversation he had with someone with a very expensive digital camera
>> hobby, who only used their cameras set to auto. Jim explained f/stop,
>> ISO and more (framing scene etc). My thanks to Jim for good story
>> with nice timing and especially foraging for the beverages.
>>
>> A fun (in theory, but probably not practical or wise) wavelength test
>> would be to use bring in blue (~400 nm) and NIR (~800nm would be
>> nice, values chosen to be 2 fold, not necessarily practical) and a
>> smoke machine (and some 400nm and NIR friendly lighting in case room
>> lights too dim at those wavelength), and demonstration resolution vs
>> ability to see through the smoke (Mie scattering etc). If you do
>> this, and the smoke alarm turns on, your school may not be happy with
>> you (though all the students may be happy to escape class early).
>>
>> Of course if they vote no to learning about f/stop and NA, you can
>> ask them how they expect to get to a million TikTok followers each
>> without knowing how to take good quality videos. Come ot think of it,
>> if they do vote yes, and you put your demo on your TikTok feed and
>> make a lot of money, you can send me the URL and a thank you check.
>>
>> On 9/19/2020 5:38 AM, F Javier Diez Guerra wrote:
>>> *****
>>> To join, leave or search the confocal microscopy listserv, go to:
>>>
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy>>> Post images on
http://www.imgur.com and include the link in your
>> posting.
>>> *****
>>>
>>> Hello,
>>>
>>> I wonder if anybody in the list could help.
>>>
>>> I want to convey to biology undergraduate students (very allergic to
>>> physics and mathematics) the understanding of the relationship
>>> between numerical aperture and spatial resolution.
>>>
>>> I have already given them links to the different microscopy primer
>>> sites. They find difficult to understand why the airy disk is
>>> generated in the image plane, how the diffraction orders affect
>>> resolution and why increasing NA reduces the image spot.
>>>
>>> Could anybody share a basic and intuitive infographic slide,
>>> animation or any other resource that could help to ease
>>> comprehension in this context?
>>>
>>> Thanks
>>>
>>> Javier
>>>
>>>
>