Operation and controls
Given that the body of the D3100 has changed so little compared to its predecessor, it's no surprise that the ergonomics are very similar. And, just as it represents the biggest change to the specifications, by far the most significant change to the handling comes from the addition of live view and movie shooting.
Live View is enabled using a prominent sprung thumb lever on the rear of the camera, just to the right of the LCD, with a red button at its center to initiate video shooting. This design makes perfect sense when you pick up the camera - the lever sits immediately next to the thumb when you take a shooting grip. It's accessible and quick to operate without the risk of accidental operation, and means that (unlike some of its competitors) the D3100 can shoot movies in any exposure mode, rather than requiring you to set the top dial to a specific movie position.
A summary of the major physical changes over the D3000 follows below:
- Live View/Movie lever
- Drive mode switch (single, continuous, timer and quiet mode)
- Rubber grip (and thumbrest)
- AE-L/AF-L button more prominent
- Buttons on rear more prominent
- New 'i' button on rear (now separated from magnification)
- GPS and HDMI ports
Rear of camera controls
The back of the camera has been carefully arranged so that the primary shooting controls are immediately available on the right-hand side of the camera. The rear dial controls exposure parameters (in concert with the exposure compensation button which sits just behind the shutter button), while the configurable AE-L/AF-L button is also within easy reach. The newly added live view lever and movie record button only require a small thumb movement to operate but are hard to trigger accidentally.
Meanwhile the buttons needed when operating the menu or on-screen display (where you're likely to have the camera held away from you to view the LCD), are all arranged down the left-hand side of the screen. Pretty well all of the controls are subtly improved over the D3000 - for example the mode dial is deeper and easier to operate, and the buttons have more positive actions.
Top of camera controls
On the top of the camera there's an 'info' button that turns the rear display on and off, and the exposure compensation button that's within easy reach of your shooting finger. The mode dial gives easy access to everything from the Guide mode through to traditional PASM exposure modes, and now gains a drive mode switch around its base. The D3100 acquires Nikon's now-standard 'Quiet' shutter mode, but loses the IR remote release option that was available on the D3000. The other thing that's missing is a bracketing option - for some reason Nikon doesn't offer this feature on its entry-level DSLRs. It won't be missed by many people but it's hard to imagine that it would cost anything to add it, making its omission seem a touch churlish.
Front of camera controls
The front of the camera plays host to a customizable function button and an active flash button. It's unusual to find such a 'Fn' on an entry level DSLR and this means the D3100 will, to a limited extent, grow with you as you develop your own chosen way of shooting. You can assign one of four functions to it (image quality/size, ISO, white balance, and Active D-Lighting), of which we suspect ISO will probably the most popular. The button is reasonably well-placed to operate using your left thumb, although its close proximity and identical shape to the flash button does mean that you can find yourself occasionally activating the flash by mistake when trying to change the ISO with the camera to your eye.
The active flash button itself is an unusually good design for this type of camera. On most models at this level this button is simply a catch that releases the flash - instead the D3100's allows you to configure its behavior too. Hold the button and spin the control dial and you can switch flash modes (including second-curtain sync), hold it and the exposure compensation button as well and you can apply flash exposure compensation - all without taking your hands out of the shooting position. It's easy to overlook nice touches like this because they all mean the camera's operation is unobtrusive.
Unlike the D90 and above, though, the D3100 cannot act as a controller for Nikon's wireless 'Creative Lighting System' flash setup - for this you need a high-end external unit such as the SB-900.