Re: sCMOS salt'n'pepper issues

Posted by Neil Anthony on
URL: http://confocal-microscopy-list.275.s1.nabble.com/sCMOS-salt-n-pepper-issues-tp7583323p7583336.html

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Hi Andrew,
I have some dark images here:
https://drive.google.com/file/d/0BzfJAGNfrgieQklEN1lnQnBKMmM/view?usp=sharing
The illumination was provided by a 488 line of a gas laser through a
(new) fiber optic to the early model Yokogawa spinning disk.

Thanks
Neil

On 1/21/2015 7:59 AM, Andrew York wrote:

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>
> Can you share raw data? Also, how are you doing your illumination?
> On Jan 20, 2015 11:19 PM, "Neil Anthony" <[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.
>> *****
>>
>> Hi all, I hope the science/optics/hardware/software/students/post-docs/
>> reviewers/managers/next-door-neighbors and FedEx are treating you well.
>>
>> We have a couple of issues with a recently installed Hamamatsu Flash 4.0
>> sCMOS camera and I was wondering if anybody has had any similar
>> experiences, both in terms of feedback on what is expected from sCMOS
>> hardware and what can be done to rectify any issues.
>>
>> Here's what we're seeing:
>> Using a Hamamatsu Flash 4.0 camera link sCMOS (firmware v3.00A) on a
>> spinning disk and acquiring data using Perkin Elmer Volocity 6.3 we're
>> having three issues regarding hot and cold pixels.  So far we have tried 4
>> different sCMOS cameras (kindly supplied/tested by Hamamatsu and Perkin
>> Elmer), to double check the subtleties, but the results are quite similar
>>
>> On the first camera we saw a bright cluster of 4 pixels that are between 2
>> and 10x greater than the surrounding pixels across nearly all imaging
>> conditions (not seen in the other three cameras).  Are these bright pixel
>> clusters something that others have seen much? This issue is seen in both
>> Volocity and ExCap/HDImage, but was not seen on the test sCMOS camera used
>> to cross check.  I also see 'ghost' clusters that look similar but only
>> seem to last for one frame...  Again, is that something seen in sCMOS
>> cameras in general?
>>
>> Salt:
>> In images with low signal and longer exposure times we see speckled bight
>> pixels using both Volocity and ExCap/HDImage, with an intensity approx
>> twice that of the background signal. Exposure times ~secs; low signal <1000
>> counts per pixel.  These speckled hot spots were seen with all sCMOS
>> cameras to some degree.
>> Pepper:
>> In almost the inverse situation, where we have higher signals with lower
>> exposure times were also seen on all sCMOS cameras (the first camera with
>> the clear hotspot had very bad 'peppering' compared to the others).
>>
>> I know that the pco cameras used on the Deltavision OMX have reference
>> images applied to reduce the affects of these artifacts, and I was
>> wondering if that's something that can be applied post-acquisition.  Any
>> thoughts and/or feedback on what's normal for an sCMOS, and how to get the
>> best out of these cameras would be much appreciated.  sCMOS cameras
>> certainly are fast and have a great signal to noise, so am I expecting too
>> much from this generation of hardware?
>>
>> Thanks
>> Neil
>>
>>
>> A couple of images to compare salt'n'pepper pixels seen on three cameras
>> are here:
>> https://drive.google.com/file/d/0BzfJAGNfrgieQ21abmVPbFBqY0k/
>> view?usp=sharing
>> https://drive.google.com/file/d/0BzfJAGNfrgieVjViTWNoeExpdDQ/
>> view?usp=sharing
>>