Aperture	Use the aperture tool when you wish gather data about stars and you want to control the Star and Sky Radius values, keeping them the same for all stars. Under , choose .  7 and 14 are good settings for most images.  Choose higher values for objects that are large such as planets. Click OK. Move your cursor over a star; click. If you wish to do another star, go back to Data Tools and select Aperture again.
Find	Use Find to obtain data on many stars at once.  Go to , choose . Click OK.  If you get too many stars, then change the 4 to another number, such as 40. Data about the stars will appear in the results box. You can go to Edit, Copy to copy all the data; then paste it into a spreadsheet program for analysis.  This is helpful if you want to compare the counts for all the stars to a standard star, etc. Click on the image to the left to see the Find results clearly.
Flip	Use the Flip options to change the orientation of images to match reference charts or other comparison images.  You can Flip horizontally or vertically.  Most of the images taken with the Univ. of Chicago Yerkes telescopes, for the HOU database, open so that North is up and East is to the left, in order to compare to common reference catalogs.

Tips 'n Tricks * Page 1 * Page 2 * Page 3 * This Page *

These Tips 'n Tricks were designed to provide you with a Quick Start to using HOU Image Processing Software. For further tools and more detailed explanations, see the HOU Curriculum materials at the Hands-On Universe website.  Http://hou.lbl.gov.