This preview window is used to display the content of an external image file.
The dialog can be activated:
When a file is opened, the program checks its content and decides which kind of preview window will be activated. Each file is presented in a separate window.
Preview window for CCD image files
(1) The CCD image is displayed in the preview area. It is possible to switch between positive and negative style in the “Preferences” dialog.
(2) When you place a cursor over an image, the coordinates and the pixel value is displayed in the status bar.
(3) You can zoom the preview in and out by means of the zoom icons on the toolbar. The actual magnification is shown here.
(4) The local menu bar provides following functions:
The Quick Photometry tool is a tool which computes basic photometric properties of an object on a frame. The main goal of this tool is to provide an estimation of the FWHM value (the important input parameter of the photometry process).
Because this tool does simplified version of aperture photometry, the results are informative only and shouldn’t be used elsewhere. Also, it doesn’t require a proper calibration to be performed first.
To activate the tool, select Tools ‣ Quick photometry from the local menu. A new panel on the right side of the preview window appears.
Quick photometry tool
Using the left mouse button, click on the image (1), close to an object. The program automatically finds the nearest local maximum, so you don’t need to be accurate. The computation stars automatically and the results are displayed the the right panel (2).
The following object parameters are presented:
It is also possible to change some parameters:
The Profile tool is used to check the shape of objects. It shows a curve of pixels values along a line.
To activate the tool, select Tools ‣ Quick photometry from the local menu. A new panel on the bottom of the preview window appears.
Profile tool
Using the left mouse button, draw a line on the image (1), crossing the center of an object. The profile is drawn in the graph (2). You can adjust the graph style (3). The following parameters are displayed in the information box (4):
The Histogram tool shows a histogram of pixel values and some related statistics.
To activate the tool, select Tools ‣ Histogram from the local menu. A new panel on the bottom of the preview window appears.
Histogram tool
The histogram is shown in the left part (1) of the tool. The following parameters are displayed in the text area on its right side (2):
See also