Nikon D3100 brings 1080p video with continuous autofocus to entry-level dSLRs

Nikon updates its popular entry-level D3000 digital SLR with the new D3100, adding full HD video with continuous autofocus.

[Updated: August 19, 2010 @ 11:19am]  It may have taken Nikon almost three years to replace its much beloved entry-level D40 digital SLR with the popular D3000 last July, but just over a year later, the company has announced a new updated version, the Nikon D3100. The new model sports a similar body to the D3000, but adds some catch-up features to the mix -- such as Live View and video recording -- which competing dSLRs have offered for some time now. But Nikon ups the ante with full 1080p HD video and continuous autofocus, along with the standard bump in resolution (up to 14 megapixels here). In fact, for both video and resolution, the D3100 also outspecs Nikon's D5000 (which I included in my Top 10 digital SLR cameras list back in June).

Continuous autofocus is something I've heard many dSLR video shooters asking for, but others will argue that continuous AF doesn't work well for shooting video with a dSLR because lenses make too much noise and make focus adjustments too slowly to produce smooth results on video.  Still, it's nice to have the option to use it if necessary (though it's too bad there's no external microphone jack to mitigate the noise factor).

Other enhancements include an updated step-by-step Guide Mode that dSLR newbies will find useful, a wider ISO sensitivity range (ISO 100 - 3200, expandable to 12,800), and a new image processing engine.

Set to begin shipping in mid September, the D3100 will sell for about $700 with an 18-55mm kit lens.

Update: Here's a quick specs comparison with some likely competitors:

Nikon D3100 Canon Rebel T1i Pentax K-x
Price $700 (with 18-55mm lens) $800 (with 18-55mm lens) $649.95 (with 18-55mm lens)
Sensor 14.2 megapixels, 23.6x15.8mm CMOS 15.1 megapixels, 14.9x22.3mm CMOS 12.4 megapixels, 23.6×15.8mm CMOS
Continuous Shooting Speed 3 fps 3.4 fps 4.7 fps
LCD 3-inch, 230,000 pixels (fixed) 3-inch, 920,000 pixels (fixed) 2.7-inch, 230,000 pixels (fixed)
Autofocus 11-point center cross-type 9-point center cross-type 11-point (9 cross-type)
Sensitivity ISO 200-3200 (100-12,800 expanded) ISO 100-3200 (12,800 expanded) ISO 200-6400 (100-12,800 expanded)
Live View Yes Yes Yes
Movie Mode 1920x1080 (24fps)/1280x720 (30fps)/640x424 (24fps) 1920×1080 (20 fps)/1280×720 (30 fps)/640x480 (30 fps) 1280×720 (24 fps)/640×416 (24 fps)
Dimensions 4.9x3.8x2.9 inches 5.1x3.8x2.4 inches 4.8×3.6×2.7 inches
Weight (body) 16 oz 16.9 oz 18.2 oz