Lab Test: Nikon D3100

It’s been a very busy year indeed for Nikon. On top of nine new lenses in 2010, last fall it announced two more camera bodies: the midlevel D7000 and entry-level D3100. The 14.2MP D3100 ($640, street, with 18–55mm f/3.5–5.6 lens) was the first to find its way to the Popular Photography Test Lab—look for our test of the D7000 next month.

In addition to adding live-view still shooting and HD-video recording to this least-expensive Nikon DSLR, the D3100 proved itself in our tests a meaningful upgrade over its predecessor, the less-than-impressive D3000.

In the Test Lab
To add live view and HD video to the D3100, Nikon switched to a CMOS sensor from the CCD of the D3000 for better control of overheating. This also raised the pixel count to 14.2MP from the D3000’s 10.2MP. In our resolution test, those extra pixels amounted to an additional 250 lines per picture height of resolving power for a total of 2350, enough to earn an Extremely High rating.

Colors proved wonderfully accurate with the D3100—its average Delta E of 6.1 was more than enough to garner an Excellent rating.

Another benefit of a CMOS sensor is the ability to push the camera’s sensitivity higher while keeping noise relatively low. While its predecessor topped out at ISO 3200, the D3100 goes 2 full stops farther, for a top sensitivity of ISO 12,800. At the same time, Nikon managed to keep noise to a Low or better rating all the way up to ISO 800, compared to ISO 200 with the D3000.

Also, while noise reached Unacceptable levels at ISO 3200 and ISO 6400, both of those settings proved significantly less noisy than the D3000 was at ISO 3200. The noise was often less distracting since the luminance noise was less pronounced than the color noise at high ISOs. So, if you’re planning on using images online, or printed at small sizes, you may find ISO 3200 passable, depending on the subject matter of your shots.

One area that didn’t see improvement is the D3100’s autofocus. Using the same 11-point Nikon Multi-CAM 1000 AF system as its predecessor, we saw, unsurprisingly, nearly identical results in our AF test. With an AF-S Nikkor 50mm f/1.4G lens attached, the D3100 took 0.50 sec to lock focus and capture an image at the brightest light level in our test. That’s about 0.2 sec slower than the Sony A390 or the Pentax K-x, and about 0.10 sec slower than Canon’s EOS Rebel T2i. If forced to choose, we’d take image quality over AF speed, but we hope Nikon speeds AF up in the next iteration of its entry-level line.