Windows 32-bit Applications:

TCA-4 Calculator V1.3.12 (Freeware) - The Takahashi TCA-4 adapter is used to achieve very high magnifications using the technique of "eyepiece projection" photography. It is typically used to make images of the moon, sun, planets, and double stars. I wrote this program to calculate the extended focal length, focal ratio, field of view, and pixel scale at the imaging plane of a camera/telescope combination using film or CCD cameras when using the TCA-4 adapter for eyepiece projection photography.

However, this application is not limited to use with the TCA-4. It can also used to calculate the field of view and pixel scale for any CCD camera without the TCA-4.

Installation: For those systems that already have Visual Basic/ActiveX components installed, try this small executable file (tca4.exe) first. If, after running the application, errors are reported that you have missing or outdated files, you should download and extract the full installation package ( After extracting (unzipping) the installation files, simply run the "Setup.exe" application.

Sample Screen

Know Problems with the software: Currently, only a limited number of cameras have binning data associated with them. I will be adding this information in future releases. The workaround is to select "User-Defined" as the CCD Camera, and enter the appropriate pixel size and chip size data.

The software is provided as is and there is no guarantee with regard to it's performance or accuracy. It is still in development stage. For those who download and use this application, please contact me to report any errors, or problems with the application, or it's installation.

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