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ctfExplorer is written by Maxim V. Sidorov
Please direct your comments, suggestions and bug reports to the e-mail address below

2000-2002, Max V. Sidorov

This software is e-postcard-ware/freeware. 
If you use it, if you find it useful, please send me an e-mail (

CtfExplorer  Overview 

CtfExplorer allows to calculate the Phase Contrast Transfer Function (CTF): a useful characteristics in Electron Microscopy 


bulletCalculates 1-Dimensional CTF
bulletCalculates 2-Dimensional CTF
bulletCalculates Defocus Map
bulletShows the effects of 2-Fold and 3-Fold astigmatism
bulletAllows to change Defocus, 2-Fold and 3-Fold astigmatism in real time
bulletShows what happens to 1D CTF in different directions when there's astigmatism
bulletDisplays the damping envelopes
bulletAllows to select a microscope from a list of microscopes
bulletAllows to create a custom microscope
bulletAllows to change HT, Cs, Cc, Energy Spread, Convergence for any microscope
bullet2 modes of operation: CTF Explorer (to see everything) and CTF Plotter
bulletCompares 2 microscopes or 2 settings for 1 microscope
bulletSaves 1D CTF, 2D CTF and "Defocus Map" as bitmaps or metafiles

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Added in 0.99b4 (30 November 2000)
bullet"Magnification" slider control. This is to show why it is not a good idea to do HRTEM at x1,000,000 magnification and why sometimes pictures taken at x200,000 look better than those taken at x500,000
bulletExport of ctfExplorer 1-D plots to tab-delimited text format
bullet"Lichte defocus" is included to the list of the most useful defoci
Service release 0.99b5 (18 August 2001)
bulletUser interface improvements and other fixes
bulletExtended list of microscopes
Added in 0.99b6 (5 December 2001)
bulletEuro-bug removed. When installed on a computer with a Windows locale which uses a comma instead of a point as a decimal separator, ctfExplorer would rise an exception when one selects a microscope from the list. 
Now it's fixed but one must use a point '.' as the decimal separator e.g. when editing a microscope. I.e. always write 1.3 instead of 1,3 etc.
Added in 0.999a (10 February 2002)
bulletCorrected an error in the formula used for Focal Spread calculation which caused too strong damping by temporal envelope at high frequencies. Thanks to Michael O'Keefe, Peter Tiemeijer and Uwe Lucken for pinpointing this.
bulletAdded a posibility to change number for High Tension and Objective Lens current instabilities (along with chromatic aberration and energy spread they affect the value of focal spread).
bulletAdded a possibility of editing/saving/restoring of the microscope list.

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Download and Installation  
(v 0.999a, February 2002)     

Installation package (~1.4 Mb)download.gif (1498 bytes)  
  1. Download ctfExplorer-package.exe and run it.
  2. That's it. A shortcut to ctfExplorer is placed to the top part of Windows Start menu. 
  3. If you ever want to uninstall: Windows Control Panel | Add/Remove | ctfExplorer.
  4. If you have problems accessing the help system then see below.

Note: ctfExplorer help system is designed in MS HTML Help format which relies on Internet Explorer's layout engine for its functionality. A full version of the browser should be installed on the end user's system. Version 4.x (or higher) is recommended for full HTML Help functionality.

ctfExplorer will not function properly (crashes on exit) without MS HTML Help system installed. 

If you have Internet Explorer 4.x (or higher) on your system but the ctfExplorer help still doesn't work (it should work fine under Windows 98-2000) then try to:

Download Hhupd.exe 1.32 (~700 KB). This version will work in all supported languages. 

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System Requirements

bulletTested with Windows 95/98/NT4/2000/XP
bulletRecommended: at least 1024x768, High color display settings, looks better with "Small Fonts" setting 
bulletReasonably fast computer. On my ancient AMD K6 350MHz with 64Mb RAM, 2d  CTF takes about 4 sec to calculate. Less than 1 sec on AMD Athlon 900MHz. Doesn't take any time at all on Athlon 2600+
bulletMS Internet Explorer Version 4 (or higher) is recommended for HTML Help functionality.

Web Design 2000-2003, Maxim V. Sidorov 

Created: 21 May 2000
Last updated: 19 April 2017