Re: remember to also CC the people you reply to

[Daniel James White]

Hi Shalin,

Thanks for the info...

I want to build a fingernail assisted speckle microscope!

but i nearly missed it...

A general mailing list point...
it might be best to always cc to the direct email addresses of the people you are replying to in your "Dear whoever"
just so we don't miss it in the digest form of the confocal list message.

Sometimes i only look at the subject list at the top of the digest email,
and might not realize there is a message addressed directly to me in there!

cheers,

Dan


On Aug 11, 2010, at 7:03 AM, CONFOCALMICROSCOPY automatic digest system wrote:

>
> Date:    Wed, 11 Aug 2010 12:11:22 +0800
> From:    Shalin Mehta <[hidden email]>
> Subject: Re: Poor man's confocal - HiLo method
>
> Hi Christophe and Daniel,
>
> For HiLo microscopy, potentially any method that can impose high
> frequency variations on the specimen fluorescence will work. It seems
> there are two 'ingredients' to the sectioning produced by the HiLo
> method:
>
> - High spatial-frequencies in the specimen are sectioned even in usual
> wide-field illumination, i.e., fast spatial variations of fluorescence
> get blurred rapidly as we defocus.
> - Low spatial-frequencies, however, are not sectioned that strongly.
> But, if we artificially turn them into high-variation structure by
> illuminating with high-frequency illumination, we gain the sectioning
> much like the above case.
>
> A nice explanation/illustration is on Jerome Mertz's website:
> http://biomicroscopy.bu.edu/r_hilo.htm
>
> The sectioned low spatial-frequencies can be extracted by low-pass
> filtering of the image taken with high-frequency illumination (e.g.
> speckle) imposed. I think speckle is a nice high-frequency
> illumination for this purpose, because it is nearly random (low but
> finite chances of artifacts) and because one can apply a fast variance
> filter to extract the in-focus low-pass regions.
>
> I have seen speckles during transmission imaging when using narrowband
> filter after halogen lamp (20 nm width around 546nm) and using the
> illumination aperture of around half that of the imaging aperture. One
> can possibly do the same with the mercury arc-lamp at the cost of
> brightness.
>
> As a side-note, I just found that under right conditions the sun-light
> reflected from fingernail  produces speckle:
> http://www.sciencenewsforkids.org/pages/puzzlezone/muse/muse0705.asp/
>
> best
> Shalin
>
> blog: shalin.wordpress.com
>
> Bioimaging Lab, Block-E3A, #7-10
> Div of Bioengineering, NUS Singapore 117574
> website: http://www.bioeng.nus.edu.sg/optbioimaging/colin/people.asp#shalin=
> m
>

Dr. Daniel James White BSc. (Hons.) PhD
Senior Microscopist / Image Visualisation, Processing and Analysis
Light Microscopy and Image Processing Facilities
Max Planck Institute of Molecular Cell Biology and Genetics
Pfotenhauerstrasse 108
01307 DRESDEN
Germany

[phone] (German Mobile)
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