Viewing the LCD monitor with Canon Log active The viewfinder and LCD monitor image when Canon Log Gamma is used will appear very flat and somewhat dark. The EOS C300 offers View Assist , to approximate how the scene would appear with a normal gamma applied.
To enable View Assist in the menu, choose LCD/VF Setup > View Assist > On/Off Note: The View Assist function is only visible on the C300's LCD screen and viewfinder. This helps ensure that the preview images output to the LCD screen and viewfinder don't affect the images recorded onto CF cards or to images output through the HD-SDI port.