WhatUSee Help:

• Your first step to use the program to make calculations about your equipement is to setup your telescope data. To do so you have to input the focal length of your system (F) and the diameter (Ø). If you are using a focal reducer (6.3, 3.3, ...) it will be easier for you to input the diameter (Ø) and the focal ratio of your reducer (f). In the "Options" menu you can choose the data you prefer to input:

• "Find (F)ocal length": introduce f and Ø to get F.
• "Find (f)ocal ratio": introduce F and Ø to get f.

• Now you have to setup your CCD (or film) camera data. The first step is to choose the chip (film) your camera uses. You can see now the FOV of your camera in your telescope and the system's resolution (FOV of a single pixel). If you do binning with your pixels your resolution will change; take a look and you will see the results. Remember that an ideal setup in an amateur's system is a resolution of about 2"(arcseconds) per pixel.
•  Maybe you are interested in doing an eyepiece projection to do planetary imaging. If you want to know your FOV you have to choose "Eyepiece projection" in the "Options" menu. You will see two new data fields in the program's window:
  • "Eyepiece": where you have to input the focal length of your eyepiece.
  • "Distance": where you have to input the distance between the lens of your eyepiece and your chip (film).

  Changing these data fields you will see how the real focal length of your complete system, it's real focal ratio, your FOV and your resolution change. Remember that you can also do binning with this technique, although it's not usually done.

• Even though the main objective of WhatUSee is to calculate the FOV and resolution of your CCD (film) camera it can also be used to calculate the FOV of any eyepiece in your telescope. To do so you have to choose "Eyepiece fields" in the "Options" menu and WhatUSee's size will increase. In the new part of the window you can calculate the FOV and magnification ratio of your eyepieces introducing the focal length ("Length") of each one and it's apparent FOV ("App. FOV º"). If you don't know the apparent FOV of your eyepiece we remind you that this value is normally 50, if you have any doubt check your eyepiece's specifications. To hide this part of WhatUSee you simply have to go back to the menu.
• When you have setup all the data of your system's configuration you can see the visual aspect of the relationship betwen all your eyepieces' FOV and your camera's FOV. To see it you will have to choose the size of the field in which you want to represent them (5º, 4º, 3º, 2º o 1º) in the "Show fields" menu of the "Options" menu. Now you can see them in the right side of your window. The graphic display of your FOVs will change every time you make a change in your configuration. If you want to change the total field represented in the image you can do it in the menu or by clicking on the buttons in the lower right side of your screen. To hide the image choose "Hide fields" in the "Options" menu.

  If you are using the KAF400 or KAF1600 chips you can also see the place and size of the tracking chip (TC211) of SBIG cameras clicking on "Show tracker".

  IMPORTANT NOTE: all the measurements used in WhatUSee are in millimeter.