Pentax K-3 Performance

Camera Reviews / Pentax Cameras / Pentax SLR i Review

Navigate Review Jump to review page...

Pentax K-3 Performance

Timing and Performance

Generally very good performance for a prosumer DSLR, but slow buffer clearing.

Startup/Shutdown
Power on to first shot	~0.9 second	Time it takes for camera to turn on and take a shot.
Shutdown	~0.2 second	How long it takes to turn off.
Buffer clearing time	26 seconds* after 75 L/P 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. See Cycle-Time table below for more buffer clearing times.
	24 seconds* after 24 RAW frames
	37 seconds* after 25 RAW + L/P JPEGs
* Note: Buffer clearing times measured with a SanDisk Extreme Pro 95MB/s UHS-I SDHC card. Slower cards will produce correspondingly slower clearing times. Slow cards may also limit length of bursts in continuous mode. ISO sensitivity and noise reduction settings can also affect cycle times and burst mode performance.

Startup was a touch slow for a prosumer DSLR, but shutdown was fast. Buffer clearing times were a little slow for the class of camera, though buffer depths were excellent.

Mode Switching
Play to Record, first shot	~0.6 second	Time until first shot is captured.
Record to Play	~1.2 seconds	Time to display a large/premium JPEG file immediately after capture.
Display recorded image	~0.4 second	Time to display a large/premium JPEG file already on the memory card.

Play to Record was very fast as was displaying a recorded image, but switching from Record to Play was a touch sluggish.

Shutter Response (Lag Time)
Full Autofocus Single Area (Spot) AF	0.138 second	Time from fully pressing shutter button to image capture. (All AF timing measurements taken with 18-135mm kit lens.)
Full Autofocus Auto (27 AF points) AF	0.157 second	Time from fully pressing shutter button to image capture.
Full Autofocus Single Area AF, Flash enabled	0.325 second	Time from fully pressing shutter button to image capture. Auto Flash enabled.
Manual focus	0.097 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."
Pre-focused	0.096 second	Time to capture, after half-pressing and holding shutter button.
Live View
Full Autofocus (Multiple AF Points) Live View mode	1.005 seconds	Time from fully pressing shutter button to image capture.
Full Autofocus (Spot AF) Live View mode	1.014 seconds	Time from fully pressing shutter button to image capture.
Pre-focused Live View mode	0.226 second	Time to capture, after half-pressing and holding shutter button.

The shutter lag numbers above measure time from shutter button press to image capture, with the lens already set to the correct focal distance. This largely removes the issue of differences in lens focusing speed, and measures how fast the camera can measure and act on focus information. In this metric, the Pentax K-3 was a touch faster than average for a prosumer DSLR, and noticeably faster than the K-5 II. The K-3 required 0.138 second for full AF when using Single-point (center) AF mode (our default full AF lag test). Enabling the flash in this AF mode increased lag to 0.325 second, though. Full AF shutter lag in Auto area AF mode was only a bit slower than single area at 0.157 second.

In a test where we defocused the kit lens between shots, autofocus lag averaged 0.593 second, giving you an idea of real-world performance. But that will vary depending on the amount of defocus, the lens mounted, subject type, lighting, etc.

Manual focus lag time was only 0.097 second, which is quite good. When prefocused, shutter lag was 0.096 second which while fast, isn't as fast as some competing models.

As expected, the Pentax K-3's Live View mode was much slower to focus. Full autofocus shutter lag was 1.005 seconds using wide-area contrast-detect AF mode. This increased slightly to 1.014 seconds using Spot AF mode. (Unlike prior models, the K-3 does not offer a phase-detect AF mode in Live View.) Prefocused shutter lag was quite good for Live View mode, however, at 0.226 second.

Cycle Time (shot-to-shot)
Single Shot mode Large/Premium JPEG	0.79 second 1 second to clear	Time per shot, averaged over 20 shots, with no signs of slowing down.
Single Shot mode RAW	0.64 second 10 seconds to clear	Time per shot, averaged over 20 shots, with no signs of slowing down.
Single Shot mode RAW + L/P JPEG	0.69 second 18 seconds to clear	Time per shot, averaged over 20 shots, with no signs of slowing down.
Early shutter penalty?	No	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/Premium JPEG	0.14 second (7.07 fps); 75 frames total; 26 seconds to clear^*	Time per shot, averaged over the buffer length of 75 shots. We did not test buffer full timing.
Continuous mode RAW	0.14 second (7.12 fps); 24 frames total; 24 seconds to clear^*	Time per shot, averaged over the buffer length of 24 frames, then slows to an average of 0.53 second (1.87 fps) for subsequent shots.
Continuous mode RAW + L/P JPEG	0.14 second (7.12 fps); 25 frames total; 37 seconds to clear^*	Time per shot, averaged over the buffer length of 25 frames, then slows to an average of 0.54 second (1.84 fps) for subsequent shots.
Flash recycling	2.3 seconds	Flash at maximum output.
* Note: Buffer clearing times measured with a SanDisk Extreme Pro 95MB/s UHS-I SDHC card. Slower cards will produce correspondingly slower clearing times. Slow cards may also limit length of bursts in continuous mode. ISO sensitivity, noise reduction and other settings can also affect cycle times and burst mode performance.

Shot-to-shot cycle times were good, at 0.79 second for Large/Premium JPEG, 0.64 second for DNG and 0.69 second for DNG + L/P JPEG files. That's quite a bit slower than the K-5 II's ~0.4 second cycle times, but still fairly good.

Continuous mode speed was very good for a prosumer DSLR, at about 7.1 frames per second regardless of file type. That's a little faster than the ~6.7 fps we got for the K-5 II, however quite a bit slower than Pentax's rating of 8.3 frames per second for the K-3. (We shoot all our continuous mode tests at ISO 200, though, and Pentax specifies 8.3 fps at ISO 100.)

The Pentax K-3's buffer depths were excellent for a prosumer DSLR, especially considering the burst rates and resolution. The K-3 managed 75 L/P JPEGs, 24 DNGs and 25 DNG + L/P JPEG frames before slowing down. (You'll likely do better with the same speed card, as the target image we use for our tests is designed to be difficult to compress.) Buffer clearing was sluggish, though, taking from 24 to 37 seconds to clear after maximum length bursts, however keep in mind buffer depths are quite generous.

The Pentax K-3's flash took 2.3 seconds to recharge after a full-power shot, which is quite fast.

Download speed
Windows Computer, USB 3.0	28,623 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 with a USB 3.0 port, downloads were the fastest we've tested thus far, but it's possible the transfer rate could be even faster with different computer hardware.

Bottom line, the Pentax K-3's performance is generally very good, with fast autofocus speeds, good shutter lag, and fast burst modes with deep buffers. Buffer clearing is however slow for a prosumer model, but perhaps not a surprise given the deep buffers and fairly large files.

Battery

Battery Life
Below average battery life for a prosumer DSLR.

Operating Mode	Number of Shots
Optical Viewfinder, (CIPA standard)	560
Live View LCD, (CIPA standard)	Unknown

The Pentax K-3 uses a custom rechargeable lithium-ion battery for power, and ships with a charger. Battery life is below average for a prosumer model so you'll probably want to get a second battery and also consider purchasing the optional battery grip which can double battery life with a second battery.

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))