A Gatan Ultrascan CCD camera has been installed on CM12 since beginning of December, 2008. Similar to the US4000 on F30, this camera is also a 4-port readout optical stack. The MTF property of this camera on 120keV is significantly better than that of US4000 on F30 under 300keV. It is expected that it can replace electron films in most of applications that use CM12, since the image quality is comparable to that of film.

Unfortunately, due to the outdated version of CM12 firmware, DigitalMicrograph doesn't communicate with our CM12. Therefore, when using DigitalMicrograph to take image, one has to manually input magnification information from scope, if you want to have accurate scale bar shown in the image. Beside DigitalMicrograph, a recent version of SerialEM has also been installed on this system. Although SerialEM is designed for Tecnai or JEOL system and to control them, it runs just fine on our CM12. It does provide flexibility and more options to drive the camera. It is recommended to use SerialEM to collect the data which is going to be processed, since, beside several other advantages, it also saves image directly into MRC format.

In this document, I first give you a couple of notes for using DigitalMicrograph and SerialEM. Then, it lists a table for calibration of magnifications and exact pixel size on CCD. Finally, there is a section regarding electron dose.

You can also get pdf version of this document here.