I used a DVI-HDMI adaptater (The one in the picture down below) for my PS3 to connect it with my 1080p PC monitor, and it works just fine.

Your output settings are set to VGA, And you'll have to reset your PS3's video settings, To do so you have to:
-1 Make sure that you have only 1 type of video cable connected between your PS3 and your TV or monitor, Wich is your HDMI cable connected to your monitor through a HDMI-DVI adaptater.
-2 Make sure your monitor is turned on.
-3 With the PS3 on standby mode (OFF), hold the power button, It will make a first beep as it turns on, after 4-5 seconds you'll hear a second beep, when you hear the second beep let go of the button, the screen would flicker and turn on, the PS3 should change to the basic 480p resolution, And a screen to confirm your video settings would appear, simply confirm it, after you do this, you'll be able to change the settings to the connection and resolution you have from the video settings.
Ta Daaah! There you go! It works!
Note that you'll have to do this everytime you change the type of the video cables ( VGA-HDMI-COMPOSITE)