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On the subject of sCMOS camera, I was told that (remember I'm not a
specialist at all so I may have misunderstood) the Andor technology (5 MPx
camera) uses independant amplification of each pixels and that this can lead
to important differences between each pixels. Whereas the Hamamatsu sCMOS
with fewer pixels (3 MPx) is different and somehow more reliable in terms of
constant gain across pixels. Does that makes sense to you ?

Christophe

On Tue, Feb 15, 2011 at 23:56, Andreas Bruckbauer <[log in to unmask]> wrote:

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>
>  Hi Jim,
>
> from the Andor Brochure:
> "The SNR superiority of sCMOS over even well-optimized Interline CCD
> technology can
> clearly be observed, manifest as better contrast of signal against a
> less noisy read noise background, resulting also in better resolution of
> features. However, comparison of the two technologies against
> backilluminated
> EMCCD (figure 2) at the weakest LED setting, showed
> that the < 1 electron noise floor and higher QE of the EMCCD resulted
> in superior contrast of the weak signal from the noise floor."
>
> seems the sCMOS still has a way to go?
> In the Andor webinar they had a slide stating that 1% of pixels have a read
> noise greater than 5 e-, so they employ a filter to reduce spurious noise.
>
> best wishes
>
> Andreas
>
>
>
>
>
>
>
>
>
>
>
> -----Original Message-----
> From: James Pawley <[log in to unmask]>
> To: [log in to unmask]
> Sent: Tue, 15 Feb 2011 22:12
> Subject:  Re: Nüvü EMCCD camera
>
>
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> >
> >I was quite surprized to read about the "most sensitive camera of the
> world"
> >in my mainstream web newspaper. Apparently a former PhD student from
> Canada
> >named Olivier Daigle has come up with a new type of EMCCD that has a lot
> >less noise that traditional ones, and has been bought "by the NASA"
> (quoting
> >the article here...). He has started a company named Nüvü that
> >commercializes the camera. You can find it on the company's website :
> >http://www.nuvucameras.com/en/en/Products.html
> >along with a spec sheet. I'm not a specialist so i was wondering what part
> >of it is hyped PR and what part is real innovation. So I'd be happy to
> have
> >the opinion of imaging specialists, what do you think ?
> >
> >Thank you
>
> Hi Christophe,
>
> As I read it, this is just an EM-CCD with a photon-counting option.
>
> Normal EM-CCDs can easily count the signal from one photoelectron/pixel
> above the read noise, but the penalty is that the single-photon pulse may
> vary tremendously in size (multiplicative noise). The photon counting
> version (That has in the past been offered by Andor and others) merely
> detects these single-photoelectron events, finds their centroid and stores
> one count in the memory at the correct location. Like all photon-counting
> systems, it is subject to "Pile-up" errors (if two, or 3 or 4) real PE are
> produced in the pixel during the exposure time, they will still be counted
> as a single event), so you must keep the signal level so low that the chance
> of there being 2 photoelectrons made during one read cycle will be very low.
>  This implies a signal rate that is really too low for most live cell
> microscopy (the cell may change as you collect your data).
>
> Alternatively, you might employ some fancy signal processing to separate
> real single PE/pixel occurrences from parts of the image where brighter
> objects are recorded. The single-PE events might be discriminated with some
> (but not total) accuracy by looking at nearby pixels or the same pixels in
> earlier and later frames. As Nyquist-sampled point objects must cover at
> least roundish patch of 12 adjacent pixels, one might be able to
> discriminate some big pules as representing 2PE because for instance, after
> processing may frames they could be seen to be from pixels towards the
> center of the image of a point object.
>
> But this seems a lot of work for a small gain and it is not clear that this
> camera tries any trick of this type.
>
> If I were looking for a new camera, I would look at the new sCMOS camera.
> No multiplicative noise (which effectively means that the QE is about 50%
> higher than the effective QE of a EM-CCD without photon counting or 50% less
> than one with photon counting) and only 1-2 electrons of noise, probably
> less than you would get from your level of non-specific staining. As well,
> you get very fast read out, massive dynamic range without saturation and a
> lot of pixels.
>
> Cheers,
>
> Jim P.
> --
> ***************************************************************************
> Prof. James B. Pawley,                Ph.  608-238-3953
>      21. N. Prospect Ave. Madison, WI 53726 USA [log in to unmask]
> 3D Microscopy of Living Cells Course, June 11-23, 2011, UBC, Vancouver
> Canada
> Info: http://www.3dcourse.ubc.ca/       Applications due by March 15, 2011
>          "If it ain't diffraction, it must be statistics." Anon.
>
>
>