http://confocal-microscopy-list.275.s1.nabble.com/Numerical-aperture-and-spatial-resolution-tp7591293p7591300.html
not all university lectures are Teams sessions. So on-site demos are not
I also align with Zdenee's view. "Why does higher NA mean higher
resolution?" is a question with no trivial answer for biologists. The
worked best for me when I first learned about spatial resolution. Still,
> *****
> 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
>>>
>>>
>