Nikon D3100 Review - Performance

Good to average speed for an entry-level digital SLR.

Startup/Shutdown
Power on to first shot	~0.4 second	Time it takes for camera to turn on and take a shot.
Shutdown	~0.1 second	How long it takes to turn off.
Buffer clearing time	2 seconds * after 20 L/F JPEGs	Worst case buffer clearing time. -- This is the delay after a set of shots before you can remove the card. Some cameras won't shut down until the buffer is cleared.
	5 seconds * after 16 RAW frames
	9 seconds * after 11 RAW + JPEG frames
*Note: Buffer clearing times measured with a SanDisk Extreme III 8GB SDHC memory card. Slower cards will produce correspondingly slower clearing times.

The Nikon D3100's startup time is about average for an SLR, but shutdown is quite fast and difficult to measure despite the fact that sensor cleaning occurs at startup and shutdown by default. (Sensor cleaning is preempted by the shutter release, and likely continues briefly after the camera is shut off.) Buffer clearing times are pretty good with a fast card.

Mode Switching
Play to Record, first shot	~0.3 second	Time until first shot is captured.
Record to Play	~1.2 seconds	Time to display a large/fine file immediately after capture.
Display recorded image	~0.1 second	Time to display a large/fine file already on the memory card.

Mode switching is pretty fast for a consumer SLR: Play to record and displaying a captured large/fine JPEG image were so fast they were difficult to measure, though switching from Record to Play immediately after capturing an image was about average.

Shutter Response (Lag Time)
Full Autofocus Single Area AF (Center AF point)	0.279 second	Time from fully pressing shutter button to image capture. (All AF timing measured with Nikkor AF-S 60mm f/2.8G Macro lens).
Full Autofocus Single Area AF, Flash enabled	0.299 second	Time from fully pressing shutter button to image capture, Auto Flash enabled.
Full Autofocus Auto Area AF	0.394 second	Time from fully pressing shutter button to image capture.
Pre-focused	0.117 second	Time to capture, after half-pressing and holding shutter button.
Continuous AF	0.200 second	This mode usually shows no speed increase with our static subject; we have no way to measure performance with moving subjects.
Manual focus	0.200 second	For most cameras, shutter lag is less in manual focus than autofocus, but usually not as fast as when the camera is "pre-focused."
Full Autofocus Live View Single-servo AF	1.49 seconds	Time from fully pressing shutter button to image capture.
Pre-focused Live View	0.479 second	Time to capture, after half-pressing and holding shutter button.

The Nikon D3100's speed in determining that it's properly focused when shooting the same target multiple times is about average for an entry-level SLR. The D3100 required about 0.28 second for full AF using the center focus point. Enabling the flash raised the lag to 0.30 second, which is pretty good, with very little delay added for the metering "preflash" there. Shutter lag increased to 0.39 second in Auto-area AF mode. Continuous autofocus and manual focus lag times were both 0.20 second. When prefocused, shutter lag dropped to 0.117 second, which is a little slower than average these days, but still pretty fast.

Full autofocus is much slower in Live View mode. The Nikon D3100 only offers contrast-detect AF in Live View, which took about 1.5 seconds to focus in our tests. (How fast the lens can adjust focus makes a big difference here.) The new Full-time AF mode (AF-F) performed about the same as Single-servo (AF-S) mode with our static subject, since it refocuses when the shutter button is pressed (it's likely more beneficial for video mode). Prefocused shutter lag is also slower in Live View mode, at about 0.48 second.

To minimize the effect of different lens' focusing speed, we test AF-active shutter lag with the lens already set to the correct focal distance. We also use the same Sigma 70mm f/2.8 macro with every camera (on all platforms except Four Thirds/Micro Four Thirds and Nikon consumer models lacking an in-body focus motor), to further reduce variation, and because our tests showed that focus-determination time with this lens was close to the fastest, across multiple camera bodies from different manufacturers. Being an older design with a non-ultrasonic motor, it wouldn't be the fastest at slewing from one focus setting to another, but that's exactly the reason we measure focus determination speed, which is primarily a function of the camera body, vs focus adjustment speed, which is primarily a function of the lens.

Cycle Time (shot-to-shot)
Single Shot mode Large Fine JPEG	0.55 second	Time per shot, averaged over 20 shots.
Single Shot mode RAW	0.54 second	Time per shot, averaged over 20 shots.
Single Shot mode RAW + L/F JPEG	0.53 second	Time per shot, averaged over 13 shots.
Early shutter penalty?	No (Yes with Flash)	Some cameras refuse to snap another shot if you release and press the shutter too quickly in Single Shot mode, making "No" the preferred answer.
Continuous mode Large Fine JPEG	0.35 second (2.89 frames per second); >20 frames total; 2 seconds to clear	Time per shot, averaged over 20 shots with no signs of slowing down. (Nikon claims a buffer capacity of 100 JPEGs.)
Continuous mode RAW	0.35 second (2.86 frames per second); 16 frames total; 5 seconds to clear	0.35 seconds for the first 16 frames, then slows to an average of 0.63 seconds (1.6 fps) with a lot of variation for subsequent frames.
Continuous mode RAW + L/F JPEG	0.35 second (2.86 frames per second); 11 frames total; 9 seconds to clear	0.35 seconds for the first 11 frames, then slows to an average of 1.04 seconds (0.96 fps) with a lot of variation for subsequent frames.
Flash recycling	3.5 seconds	Flash at maximum output.
*Note: Buffer clearing times measured with a SanDisk Extreme III 8GB SDHC memory card. Slower cards will produce correspondingly slower clearing times. Slow cards may also limit length of bursts in continuous mode. ISO sensitivity and other settings such as Advanced D-Lighting or NR can also affect cycle times and burst mode performance.

Shot-to-shot cycle times were about average for an SLR, at 0.55 second for large/fine JPEGs, 0.54 second for RAW files, and 0.53 second for RAW + Large/Fine JPEG frames. Continuous speed is about average for an entry-level SLR these days as well, at about 2.9 frames per second for any quality. Buffer depths are pretty good for a budget model though, at over 20 large/fine JPEG frames, 16 RAW frames and 11 RAW + Large/Fine JPEG frames. (We use a difficult to compress target, so results with typical scenes should be better; Nikon claims bursts of 100 JPEGs are possible.) The flash takes 3.5 seconds to recharge after a full-power shot, which is pretty good.

Download speed
Windows Computer, USB 2.0	9,504 KBytes/sec	Typical Values: Less than 600=USB 1.1; 600-769=USB 2.0 Low; Above 770=USB 2.0 High

Connected to a computer or printer with USB 2.0, download speeds are quite fast.

Bottom line, the Nikon D3100 is about average when it comes to autofocus, shutter lag and continuous mode performance. It should be fine for most family situations, including some limited action shots.

Battery
Average battery life for a lithium-ion design.

Operating Mode	Number of Shots
Optical Viewfinder, (CIPA standard)	550

The Nikon D3100 uses a custom rechargeable lithium-ion battery for power, and ships with a charger. Battery life when using the optical viewfinder is about average for a consumer SLR. Nikon does not specify battery life for Live View mode, but it will certainly be a lot lower, so we recommend you pick up a spare battery and keep it freshly charged and on-hand for extended outings or when using Live View.

The table above shows the number of shots the camera is capable of (on either a fresh set of disposable batteries or a fully-charged rechargeable battery as appropriate), based on CIPA battery-life and/or manufacturer standard test conditions.

(Interested readers can find an English translation of the CIPA DC-002 standards document here. (180K PDF document))

Storage
The Nikon D3100 accepts SD/SDHC/SDXC memory cards, and no card is included with the camera.

Image Capacity with 1GB Memory Card		Fine	Normal	Basic	RAW (12-bit)	RAW + Fine JPEG
4,608 x 3,072	Images (Avg size)	115 8.9MB	228 4.5MB	425 2.4MB	56 18.1MB	37 27.1MB
	Images (Avg size)	115 8.9MB	228 4.5MB	425 2.4MB	56 18.1MB	37 27.1MB
	Approx. Compression	5:1	10:1	18:1	1.2:1	-
3,456 x 2,304	Images (Avg size)	203 5.0MB	375 2.7MB	750 1.4MB	-	-
	Images (Avg size)	203 5.0MB	375 2.7MB	750 1.4MB	-	-
	Approx. Compression	5:1	9:1	18:1	-	-
1,936 x 1,296	Images (Avg size)	425 2.4MB	825 1.2MB	1,500 683KB	-	-
	Images (Avg size)	425 2.4MB	825 1.2MB	1,500 683KB	-	-
	Approx. Compression	4:1	9:1	16:1	-	-

We strongly recommend buying a large capacity SDHC card, at least a 4GB card, preferably an 8 or 16GB one, to give yourself extra space for extended outings or when shooting RAW or video. (Check the shopping link above, cards are really cheap these days, so no reason to skimp.)