What do I need to setup two devices as secondary monitors from the iMac? Least complicated solution for have both a preview monitor and projector (running the same image) from the MiniDisplay Port. Thanks for any input. Some colleagues purchased a Mid 2010 21.5" iMac as a Media Shout solution. Our workflow/line of devices now is: iMac > Apple MiniDisplay to DVI adapter > DVI cable > Kramer VP Scaler/Switcher (DVI input) > VGA cable (only output) > Kramer 1:3 VGA Distribution Amplifier > Cable run to projectors (LC-XGC500L). Problem is no preview monitor. Hoping to have the preview monitor prior to the Kramer so if there is a need to setup a different program or slide, we will be able to see what we are doing on the monitor, while the Kramer is set to black. Trying to troubleshoot. If I split the Mini DisplayPort at the iMac to the Kramer and preview monitor, must they both be at the same resolution and Hz? I can't get both the projectors and monitor except the signal at the same time. Again thanks for any input.