Pedro Almada |
*****
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. ***** Dearest mailing list, I am a cell biologist currently assembling a super-resolution microscope. Currently I am trying to get my head around the consequences of not fulfilling etendue. Our plan is to underfill the tube lens since we would like to restrict the laser illumination to only the areas which are covered by the camera sensor, as to make efficient use of our laser power (this is to be a dSTORM system). Reading through the handbook, there is only a few passing mentions of etendue/Abbe sine condition and one of them is in the coma section, which is worrying since we would like to do 3D dSTORM. My question is: what aberrations should I expect from not filling the aperture of the tube lens to the field number of the microscope objective? It's not going to be a massive underfill as we are planning on using an sCMOS camera (18.8mm diagonal) with a Nikon objective (25mm FN). Any input would be appreciated! Thank you, Pedro PhD Student MRC Laboratory for Molecular Cell Biology University College London Gower Street London WC1E 6BT Telephone: +44 (0)20 7679 7806 |
Andrew York |
*****
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. ***** If I understand you correctly, you mean you'll restrict the diameter of your excitation laser so it doesn't overfill your tube lens? This is a fine plan. The shape of your excitation has no effect on your emission PSF. Pay careful attention to your emission path, but the excitation path for palm/storm doesn't matter much. On Fri, Jan 16, 2015 at 11:17 AM, Pedro Almada <[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. > ***** > > Dearest mailing list, > > I am a cell biologist currently assembling a super-resolution microscope. > Currently I am trying to get my head around the consequences of not > fulfilling etendue. Our plan is to underfill the tube lens since we would > like to restrict the laser illumination to only the areas which are covered > by the camera sensor, as to make efficient use of our laser power (this is > to be a dSTORM system). > > Reading through the handbook, there is only a few passing mentions of > etendue/Abbe sine condition and one of them is in the coma section, which > is worrying since we would like to do 3D dSTORM. My question is: what > aberrations should I expect from not filling the aperture of the tube lens > to the field number of the microscope objective? It's not going to be a > massive underfill as we are planning on using an sCMOS camera (18.8mm > diagonal) with a Nikon objective (25mm FN). > > Any input would be appreciated! > > Thank you, > Pedro > > PhD Student > > MRC Laboratory for Molecular Cell Biology > University College London > Gower Street > London > WC1E 6BT > Telephone: +44 (0)20 7679 7806 > |
Zdenek Svindrych-2 |
In reply to this post by Pedro Almada
*****
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. ***** Dear Pedro, this has nothing to do with Abbe sine condition. And the term 'underfilling tube lens' is somewhat exotic... I believe the illumination is important in STORM. Although it won't affect your widefield resolution, it may have great impact on background fluorescence (and high background kills superresolution very efficiently :-) . I got good results following these steps: 1) strong illumination - you need quite strong solid-state lasers, the bigger the are of the iluminated FOV the higher power is needed. Although I' ve observed blinking with LEDs, Hg lamps and even a spinning disc confocal, it's impractical. Bear in mind that by blocking some light you won't get more light anywhere... 2) homogeneous illumination - surprisingly, in STORM areas that receive less illumination may produce much more fluorescence, possibly saturating your detector. Even minor variations in intensity may bring about artefacts in the reconstructed images. Sharply limited illumination is a good idea. It's simple, you just put an iris into a position that is conjugated with the sample plane (i.e. in focus at the same time). Try to get your hands on some microscope with an adjustable field stop in the fluorecence illumination path, e.g. Olympus IX with an 'L-shaped illuminator'. 3) good cooled camera - don't forget we're photon-limited! 4) good localisation and rendering software 5) perfect sample - that's the tricky part - to get reproducible blinkink with more than 1 in 100 samples. There are number of recipes to try out. Note: It's hard to achieve uniform illumination with a laser. The speckle is everywhere. Generally I got good results when following 'telecentric' (also called '4-f') principles with either 'Abbe' (for single mode free beam or vibrating diffusers) or 'critical' (for multimode, vibrating fiber) illumination. It always helps if there is some sort of mechanical vibration in your setup to destroy the laser coherence... Best, zdenek P.S.: there are a couple of state-of-the-art STORM labs in UK, I'm sure it's going to be very useful (and fun) to visit one of those... -- Zdenek Svindrych, Ph.D. W.M. Keck Center for Cellular Imaging (PLSB 003) University of Virginia, Charlottesville, USA http://www.kcci.virginia.edu/workshop/index.php ---------- Původní zpráva ---------- Od: Pedro Almada <[hidden email]> Komu: [hidden email] Datum: 16. 1. 2015 11:19:21 Předmět: What happens if I dont meet Abbe's sine condition by underfilling a tube lens with a laser? "***** 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. ***** Dearest mailing list, I am a cell biologist currently assembling a super-resolution microscope. Currently I am trying to get my head around the consequences of not fulfilling etendue. Our plan is to underfill the tube lens since we would like to restrict the laser illumination to only the areas which are covered by the camera sensor, as to make efficient use of our laser power (this is to be a dSTORM system). Reading through the handbook, there is only a few passing mentions of etendue/Abbe sine condition and one of them is in the coma section, which is worrying since we would like to do 3D dSTORM. My question is: what aberrations should I expect from not filling the aperture of the tube lens to the field number of the microscope objective? It's not going to be a massive underfill as we are planning on using an sCMOS camera (18.8mm diagonal) with a Nikon objective (25mm FN). Any input would be appreciated! Thank you, Pedro PhD Student MRC Laboratory for Molecular Cell Biology University College London Gower Street London WC1E 6BT Telephone: +44 (0)20 7679 7806" |
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