Manual Exposure Mode
A correct exposure of a landscape shot is very important. Even though modern digital cameras features advanced algorithms to calculate the right exposure, they still may fail some difficult conditions. Manual exposure mode in these conditions helps a lot in order to achieve correct exposure. Manual Focus Mode
With the manual focus mode, you can make fine adjustments to have the perfect focus. 28 mm - Good Wide Angle Coverage
Even though there are very good examples of landscapes photos taken with tele lenses, most of the landscape photos are taken with wide angle lenses. RAW shooting capability
RAW files contains much more color information compared to JPEGs, and gives you more room for post processing without significant quality loss. They provide wider dynamic range and option to recover shadow and highlight clipping to some degree.
Small 1/1.7" (7.44 x 5.58 mm) sensor
Canon G12's small sensor struggles in low light situations compared to larger sensors. Very Low Resolution Sensor: 10.0MP
Landscapes photography is where you need the maximum resolution. Unfortunately Canon G12's 10.0MP sensor doesn't deliver much and limit you with smaller prints and less fine details. No Environmental Sealings
Landscape photographs are taken outdoors and you should be prepared for all kind of weather conditions.