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Hi Colin,

Could you (and Gerhard/PCO and someone from Hamamatsu) please explain 
why you are not correcting the gain for every pixel, re: the mess shown 
in Huang ... Bewersdorf et al 2013, 
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3696415/ , supplemental 
figure 1,

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3696415/bin/NIHMS475969-supplement-1.pdf

This should be doable at the camera device driver level (would be nice 
if implemented 'realtime' on a GPU or Intel Phi card) so that everyone 
who owns any of your cameras could get this for just the effort of a 
driver update.

thanks in advance,

George

On 5/15/2014 11:46 AM, Colin Coates 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.
> *****
>
> **Commercial response**
>
> Hi,
>
> Just to chip in on the question of manipulating the FPGA processing
> functionality of the Zyla.
>
> Gerhard indeed gave a good synopsis of what real time processing goes on
> in sCMOS cameras, in order to turn raw images into acceptable images. In
> theory its possible to crack in and switch stuff like this off, but in most
> cases its not recommended. For most part, they are implemented in order
> to bring us to the situation we are used to with CCDs, except with lower
> noise, faster speed and wider dynamic range of course! That is to say, the
> processing is in place in order to provide us with a nice stable and uniform
> bias offset, with low read noise sitting on top, and uniform responsivity to
> light across the array.
>
> The most fundamental normalisation we do is to patch up the fixed pattern
> noise in the bias (baseline) offset. A comparison with and without is shown
> on P20 of the Andor sCMOS brochure:
>
>
>
> http://www.andor.com/pdfs/literature/Andor_sCMOS_Brochure.pdf
>
>
>
> Then there's a further round of real time bias correction called Dynamic
> Baseline Clamp.
>
> Gerhard also mentioned gain compensation. This is indeed implemented to
> normalise for slight responsivity differences between sCMOS pixels. A
> further side effect of not implementing this compensation would be to
> discernibly identify the two halves of the sensor when the sensor is
> illuminated.
>
>
>
> In our experience, the one area of real time processing that can represent
> a problem to people's usage, especially in pointillist super-resolution, is
> interpolative pixel filtering (referred to by Gerhard in context of hot pixels).
> In fact, Andor have now provided a means to switch off all interpolative
> filtering, such that no pixel values are replaced. Furthermore, if useful,
> we'll work with you to provide maps of where problematic pixels are
> located, such that at least you are aware of them. We are close to releasing
> a technical note on this to provide further detail and instruction. If you are
> interested, please contact my colleague Orla Hanrahan
> ([log in to unmask]) for specific detail.
>
>
>
> Best,
>
> Colin
>
>
>
> Dr Colin Coates
>
> Product Manager
>
> Andor Technology
>
>
>
>
>
>    


-- 



George McNamara, Ph.D.
Single Cells Analyst
L.J.N. Cooper Lab
University of Texas M.D. Anderson Cancer Center
Houston, TX 77054
Tattletales http://works.bepress.com/gmcnamara/26/