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FEI TF20 Microscope Parameters

wavelengths

* 200kV: 0.02508 A

objective lenses

  • f=
  • Cs = 2.1 mm
  • Chromatic aberration =

Aperture Sizes

  • Condensor : 150 um, 70 um, 50 um, 50 um
  • Objective : 50 um, 50 um, 50 um, 40 um
  • Selected Area: 200 um, 100 um, 70 um, 40 um

CCD information

  • Size of camera : 4096 x 4096 pixels
  • Pixel size: 15 um
  • Post-film mag : 1.76
  • Gain in SerialEM : 29 counts / electron
  • Gain in EM Menu3: 14.5 counts / electron

CCD : Signal to noise ratio in comparison to film

  • SNR of tecnai CCD:
    tecnai-ccd.png
  • SNR -tecnai film:
    tecnai-film.png

Magnification Calibration: Tecnai F20

  • Magnifications calibrated using 2160 cross grid using method described in SerialEM documentation
Set Magnification (screen up) CCD Magnification Unbinned Pixel Size (A) 2X Binned Pixel Size (A) Tilt Axis Angle calibrated film mag
2100 (LM) 3,624 41.4 110 -80.2  
1,700 2,977 50.4 100.8 90.8  
2,500 4,403 34.1 68.1 90.9  
3,500 6,037 24.8 49.7 91.8  
5,000 8,938 16.78 33.6 91.3  
6,500 11,467 13.08 26.2 91.2  
7,800 13,824 10.85 21.7 91.1  
9,600 17,088 8.78 17.56 91.1  
11,500 20,348 7.37 14.74 91.0  
14,500 25,857 5.80 11.60 90.8  
19,000 33,904 4.42 8.85 91.0  
25,000 42,611 3.52 7.04 90.9  
29,000 50,592 2.96 5.93 90.8  
50,000 88,249 1.700 3.40 92.4 51,190 +/- 90 (n=13) 51,787 +/- 90 at 120kV (n=14)
62,000 108,857 1.378 2.76 92.4 63,410 +/- 104 (n=12) 63,735 +/- 160 at 120kV (n=10)
80,000 139,813 1.073 2.15 92.4 81,190 +/- 111 (n=4)
150,000 270,800 0.554 1.11 ND gold lattice
200,000 357,100 0.420 0.840 ND gold lattice
240,000 427,400 0.351 0.702 ND gold lattice
280,000 505,100 0.297 0.594 ND gold lattice
390,000 694,400 0.216 0.432 ND gold lattice
490,000 862,100 0.174 0.348 ND gold lattice
700,000 1.250M 0.120 0.240 ND gold lattice

  • Average CCD to film factor: 1.76
  • fim mags calibrated using negative-stain TMV, measuring height of layer line at 23A

Leginon: Goniometer model

  • X axis
xcal2.png

  • Y axis
ycal.png

-- BillRice - 28 Sep 2007

* filmcal.zip: film calibrations 200kv

* filmcal_tecnai_2011.zip: film calibrations 200kv