Nikon D3100: Performance

PERFORMANCE
The 18-55 kit lens provided with the D3100 makes a compact and light combination. Adding the 55-300 lens introduced at the same time as the D3100 gives this little camera a one-two punch covering the 27 to 450mm focal range in 35mm equivalents.

Shooting Performance
The D3100 powers up promptly and you can fire off a first shot as quickly as you can flip the power switch, focus and go full push on the shutter button - about 0.6 to 0.7 seconds in my case.

Single shot-to-shot times were basically as fast as you could shoot, focus and shoot again - about 0.5 seconds - and the camera made the advertised 3 fps continuous shooting rate for 24 JPEG fine images, slowing to about 2.5 fps and holding at that rate past image number 40 when I stopped the sequence.

Shutter Lag (press-to-capture, pre-focus)

AF Acquisition (press-to-capture, no pre-focus)

Continuous Shooting

*Note: Continuous shooting framerates are based on the camera's fastest full-resolution JPEG continuous shooting mode, using the fastest media type available (300x CF, SDHC, etc.). "Frames" notes the number of captures recorded per burst before the camera stops/slows to clear the buffer.

The D3100 seemed to acquire focus and shoot in average entry-level speed in the field, and generated 0.14 and 0.04 second timings in the focus acquisition and shutter lag categories, respectively. Truth be told, the shutter lag on the D3100 wasn't something that was apparent - the camera seemed to shoot promptly - but the timing is among the slowest in the entry level class of cameras. The lens proved a bit slow going from focus at one end of the focal range to the other, such as when shooting a bug on a leaf at about 12 inches and then shooting a tree at infinity, but this is not an unusual occurrence. My 70-200mm f/2.8 on the D3100 was a bit slow going from extreme to extreme as well, although quicker than the kit lens. For most shooting situations users won't notice unusual delays in acquiring focus or getting off a shot.

The 11-point Multi Cam 1000 AF system on the D3100 did a fairly good job of tracking moving subjects - not as good as Nikon's 51 point systems on the D300/300s or D3/3s, but good by entry level standards. Nikon's D200 has the Multi Cam 1000 as well, and the D200 was Nikon's prosumer class body during the time of the pro-bodied D2x/D2xs, so yesterday's prosumer AF system has found its way into today's entry level unit (as well as the D3000).

The built-in flash has a guide number of 43, which translates into approximately a 12 foot range at maximum aperture (f/3.5) and 100 ISO - about average in the entry-level class. Flash recycle times varied from almost instantaneous in good conditions to about 3.5 seconds in dim light with a full discharge. Here's a couple hummingbirds caught with the flash.

Battery life is listed as approximately 550 shots using a CIPA standard involving single frame release mode shots. I've always found CIPA ratings to be pretty accurate, so going by this figure, the D3100 is not overly strong in this regard. Nikon lists a battery life of approximately 2000 shots using a continuous release mode shooting cycle, but err on the side of caution and consider the CIPA figure as a guideline at least until you can get an idea of what your individual shooting style does to battery life. Battery life can also be impacted by frequent autofocus operations, use of the monitor, capturing RAW images and using vibration reduction (stabilization).

If your first reaction to the part about stabilization is that the feature is something you'd always want on, you're in the overwhelming majority of folks who feel the same. I used to. However, Thom Hogan is a Nikon pro who has studied the Nikon VR system, conducted test shoots, and talked to other pros and Nikon engineering guys, and he suggests the Nikon VR system should be turned off unless you need it and in any event at shutter speeds above 1/500th of a second.

The explanation is lengthy, somewhat technical and can be found on Thom's website, which has a wealth of Nikon-specific information along with generic tips and info. I'm not affiliated with Hogan or his site, but I've been following his guidelines with regard to when and when not to enable VR in my personal shooting, and I'm happy with the results. The D3100 does not have an abundance of battery power, so any savings users can make will help stretch each battery a bit further.

Lens Performance
The 18-55mm kit lens was a little soft in the corners at the wide end, but did a fairly good job at telephoto, with even sharpness across the frame. There's some barrel distortion at wide angle that goes away around 35mm. Chromic aberration (purple fringing) was present at both ends of the zoom, but generally required 200 to 300% enlargement to be readily visible in most cases. The 18-55 does a pretty good job overall, but in some instances a close and critical inspection of images will disclose some fringing at 100%.

One nice aspect of the 18-55 is the close focus range of about 11 inches across the entire focal range. That 11 inches is from the subject to the sensor focal plane in the camera, not subject to lens, so the 18-55 offers a fairly decent close-up capability without having to resort to a dedicated macro lens. Here's a shot of our prized mittens from the 2010 winter Olympics and a close-up of some mitten detail with the 18-55:

But if the close-up bug bites, you can always go macro - here's the view with our 105mm Nikkor micro lens:

The 55-300 was a little soft on the left and right edges at wide angle, but likewise looked fairly consistent at telephoto. There's a hint of barrel distortion at wide angle that goes away at about 70mm, then pincushion distortion appears out to the telephoto end. Purple fringing is present in some high contrast boundary areas across the whole focal range, but generally needs 200 to 300% enlargement to be readily visible. Sharp-eyed scrutiny of shots can reveal fringing at 100% in some cases.

A word here about the 55-300 lens: light, relatively small and stabilized, this lens makes a pretty nice walking about combination with the D3100 for folks who need a relatively long telephoto focal range. That's the good news. The other side of the coin is the lens is fairly slow, with maximum apertures of f/4.5 and 5.6 at the wide and tele ends of the zoom, respectively. The max aperture jumps to f/4.8 at about 100mm; f/5 shows up not too far past 135mm; f/5.3 at 200 and f/5.6 arrives about 225mm. The lens uses Nikon's VR stabilization which is reported to offer "up to" 3 stops of improvement over an unstabilized lens in combating camera shake, but users should consider additional camera support to maximize image quality when shooting this lens toward the long end of the focal range.

Most lenses are sharper stopped down a bit from maximum aperture, which in the case of the 55-300 at the tele end means at least f/8, which combined with the camera's base 100 ISO and a dimly lit or relatively dark subject/scene may result in fairly slow shutter speeds that can compromise image sharpness, even with stabilization. I took about 30 shots of this scrub jay hand holding the 55-300 and this was the best shot - the rest were all a bit blurred by either camera or subject movement.

The shot isn't too bad, but not as sharp as this one, shot as part of a series of about 20 shots using a tripod - and virtually all of the tripod shots were as good.

The point is that even with stabilization, as lens focal lengths get longer, be it with a DSLR or compact digital, camera shake becomes your worst enemy when it comes to image quality and any camera can benefit from a more stable shooting position. Consider a tripod or monopod if your shooting style involves a lot of work in the longer telephoto ranges. I also shot some of this review at ISO 200 to get back a stop of shutter speed without virtually any noise penalty over the base ISO.