[3dem] K3 CDS mode issue

[Matthijn VOS]

Exactly the same experience at Institut Pasteur. Took more than a year, then GMS upgrade, gatan engineer playing with the settings and gain recorded not at the dose rate requested by the procedure, but a bit higher.

No explanations from gatan as were the origin of this all comes from. To this day not very satisfied and working on replacing it with a TF filter and camera.

Happy holidays!

On Dec 17, 2021, at 13:06, Wim Hagen <hagen at embl.de> wrote:



Hi Dan,

Our K3 has/had this exact problem from the very start when it was installed. For SPA one can somewhat work around the problem, but it’s a killer for tomography. Gatan played a bit with the detection settings for CDS mode (which required a GMS upgrade), that somewhat fixed the gain ref symptoms, but a subsequent ApoF SPA test of normal vs CDS mode showed zero difference in performance. We kinda left it there and only use normal mode on that system.

Hearsay:
- Some systems have this in normal mode, or CDS mode or both modes.
-Some systems were fine after swapping the chip.
- One system was fine after swapping the K3 power supply.

Best,

Wim Hagen
EMBL Heidelberg


> On 17. Dec 2021, at 02:44, Daniel Toso <dtoso at berkeley.edu> wrote:
> 
> Hello Everyone,
>
> We have been having an issue with one of our older K3 cameras since last year. Namely, in CDS mode we are getting stripes in our images that do not get removed by gain correction and become worse as the dose goes further from 7.5 e-/pixel/sec., which will occur quite often in thicker ice. See attached image for an example.
>
> We tried having Gatan (Ametek) fix the issue but they do not have a solution beyond buying a new sensor.
>
> I was wondering if this is a widespread issue. Also, if there is any solution besides no longer imaging in CDS mode. We have heard that it is also seen at UCSF. Any advice would be appreciated.
>
> Thanks very much!
>
> Best regards,
>
> Dan
[cid:c83a1de0-c258-41db-a246-558c25bab213 at corp.pasteur.fr]
> _______________________________________________
> 3dem mailing list
> 3dem at ncmir.ucsd.edu
> https://urldefense.com/v3/__https://mail.ncmir.ucsd.edu/mailman/listinfo/3dem__;!!JFdNOqOXpB6UZW0!9vF5z_1W-eVZmSon_oIp055wuboPJvquDo4-2pyT6Z469lEpFAflpvmMk9HLyCLvZ7hNNg$
_______________________________________________
3dem mailing list
3dem at ncmir.ucsd.edu
https://urldefense.com/v3/__https://mail.ncmir.ucsd.edu/mailman/listinfo/3dem__;!!JFdNOqOXpB6UZW0!9vF5z_1W-eVZmSon_oIp055wuboPJvquDo4-2pyT6Z469lEpFAflpvmMk9HLyCLvZ7hNNg$
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.ncmir.ucsd.edu/pipermail/3dem/attachments/20211217/d014ea1d/attachment-0001.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: Screenshot_at_2021-12-08_13-13-14.png
Type: image/png
Size: 69991 bytes
Desc: Screenshot_at_2021-12-08_13-13-14.png
URL: <http://mail.ncmir.ucsd.edu/pipermail/3dem/attachments/20211217/d014ea1d/attachment-0002.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: Screenshot_at_2021-12-08_13-13-14.png
Type: image/png
Size: 69991 bytes
Desc: Screenshot_at_2021-12-08_13-13-14.png
URL: <http://mail.ncmir.ucsd.edu/pipermail/3dem/attachments/20211217/d014ea1d/attachment-0003.png>