Pay particular attention to the part where OPTION clicking is discussed - a lot of folks miss that bit!
Configuring Mac Projector Settings
Start by opening the Display preferences by going to Apple menu > System Preferences > Displays > Arrangement as seen below. Make sure Mirror Displays is checked. If you do not have an Arrangement tab then your projector is not properly plugged in. Double check all your connections.
With Mirroring on, click the Display tab and you should see something like the following screen (exact appearance can vary slightly).
The Optimize for: popup button should be set to Display which represents your projector. It should not be set to Built-in Display or iMac or Laptop or anything like that.
Next OPTION click the Scaled button to see all possible projector sizes. Holding down the OPTION key while clicking is critical. You'll see something like the following screen where you can select 1280 x 768:
The 1280 x 768 works very well for most of our projectors and your Mac will automatically change its screen size to best match.
Please note if the image on your project is not filling most of your board then the projector may be in widescreen mode. To fix this press the Aspect button on your projector remote until the image fills your board:
Omaha Public Schools does not discriminate on the basis of race, color, national origin, religion, sex, marital status, sexual orientation, disability, age, genetic information, citizenship status, or economic status in its programs, activities and employment and provides equal access to the Boy Scouts and other designated youth groups. The following individual has been designated to address inquiries regarding the non-discrimination policies: Superintendent of Schools, 3215 Cuming Street, Omaha, NE 68131 (402-557-2001).
Las Escuelas Públicas de Omaha no discriminan basados en la raza, color, origen nacional, religión, sexo, estado civil, orientación sexual, discapacidad , edad, información genética, estado de ciudadanía, o estado económico, en sus programas, actividades y empleo, y provee acceso equitativo a los “Boy Scouts” y a otros grupos juveniles designados. La siguiente persona ha sido designada para atender estas inquietudes referentes a las pólizas de no discriminación: El Superintendente de las Escuelas, 3215 Cuming Street, Omaha, NE 68131 (402-557-2001).