Re: Condenser lens choice for a given objective

Posted by Zdenek Svindrych-2 on
URL: http://confocal-microscopy-list.275.s1.nabble.com/Condenser-lens-choice-for-a-given-objective-tp7584901p7584929.html

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Hi,



See e.g. Handbook of biological confocal microscopy (2nd ed), ed. J.B.
Pawley, chapter 1 page 1 equation 1:

d_min = lambda / (NA_obj + NA_cond)

 - this is the spacing of a grating that is just resolvable in trasmitted-
light microscopy, so condenser and objective NA have equal impact on the
resolution (this has been used to get gigapixel images with low mag low NA
large FOV objective and high NA illumination + some tricks).




equation 2 at the same page:

r_Airy = 0.61*Lambda/NA_obj

 - this is the airy disk radius of an image of an infinitely small luminous
point, does not matter whether trans-illuminated or fluorescent. This
changes as there are more 'points', their 'airy patterns' interfere in trans
-illuminated microscopy and equation 2 cannot be used. It's more useful in
fluorescence microscopy.




Disclaimer: I only understand fluorescence, to some extend. Not the rest...




zdenek




---------- Původní zpráva ----------
Od: Kyle Douglass <[hidden email]>
Komu: [hidden email]
Datum: 21. 3. 2016 7:35:42
Předmět: Re: Condenser lens choice for a given objective

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Hi all,

On 03/21/2016 11:35 AM, Guy Cox wrote:
> OMG, can nobody here read?
>
> Resolution in transmitted light bright field microscopy depends just as
much on the condenser NA as on the objective's NA.
>
> NO, NO, NO!!!!!!!! I refuse to repeat myself, just go back and reread this
thread.
>
> Guy
>

Thanks for your correction, Guy. I do in fact see your e-mail that
states that the condenser NA only affects brightness and not resolution.
Would you happen to have a reference, either an article or a text book,
that discusses this so I can try to understand your argument better? You
can e-mail it to me off list if you'd like.

Thanks again everyone for your help,
Kyle

--
Kyle M. Douglass, PhD
Post-doctoral researcher
The Laboratory of Experimental Biophysics
EPFL, Lausanne, Switzerland
http://kmdouglass.github.io
http://leb.epfl.ch"