The camera body design remains largely unchanged. The D3100 has a pleasant heft and grips well; it's a diminutive DSLR camera, around the same size as the D3000 but slightly lighter. The physical controls remain similar, but there are two useful additions. A Shooting Mode dial has been added under the Mode dial. And while there's usually a Video mode on the Mode dial of HD DSLR cameras, there's none on the D3100, which took some getting used to. Instead, a flip has been added beside the LCD to switch between viewfinder and Live View mode; its small size and inherent 'springiness' make it hard to activate, but the dedicated Record button makes it easy to shoot video.
From the initial four buttons on the left of the LCD screen, there are now five on the D3100, and have been pushed even further to the edge of the body. The new dedicated Info button gives you quick access into the interface where you can quickly change settings like ISO speeds, metering and AF modes. The d-pad is roomy, and lets you select any of the 11 AF points easily.
Imagine the Guide shooting mode as a semi-Auto/Manual mode with a built-in interactive manual. It guides you through which settings to use depending on what you want to shoot, like portraits, landscapes or even 'sleeping faces.' New to the D3100 are previews, which show you the effect different settings have on an image, how a wider aperture gives you a softer background for example. While Guide mode may be useful for beginners, it feels like too many hoops to jump through when in the field hunting for magic moments, and is probably more suited to an afternoon at home dedicated to learning about your camera.