Pentax K-r Performance


Timing and Performance

Generally excellent performance for an entry-level consumer digital SLR.

Startup/Shutdown

Power on
to first shot

~0.3 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

12 seconds *
after 30 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.

17 seconds *
after 13 RAW files
17 seconds *
after 10 RAW + L/F JPEGs

*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 D-Range or NR can also affect cycle times and burst mode performance.

The Pentax K-r's startup and shutdown times were quite good for a consumer SLR. Buffer clearing times were a bit sluggish, but understandable given the relatively deep buffer depths.

 

Mode Switching

Play to Record,
first shot

~0.3 second

Time until first shot is captured.

Record to Play

~2.2 seconds

Time to display a large/fine file immediately after capture.

Display
recorded image

~0.2 second

Time to display a large/fine file already on the memory card.

Play to Record mode delay was very good for a consumer SLR, though switching from Record to Play was quite sluggish.

 

Shutter Response (Lag Time)
Optical Viewfinder

Full Autofocus, Single-Point AF (center point)

0.105 second

Time from fully pressing shutter button to image capture (with Sigma 70mm f/2.8 prime).

Full Autofocus,
Auto-Area AF
0.118 second
Time from fully pressing shutter button to image capture (with Sigma 70mm f/2.8 prime).

Full Autofocus, Single-Point AF
Flash enabled

0.153 second

Time from fully pressing shutter button to image capture, Auto Flash enabled (with Sigma 70mm f/2.8 prime).

Pre-focused

0.097 second

Time to capture, after half-pressing and holding shutter button.

Continuous AF
0.099 second
This mode usually shows no speed increase with our static subject; we have no way to measure performance with moving subjects.
Manual focus
0.098 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."
Live View Mode

Full Autofocus, Phase-Detect AF

1.197 seconds

Time from pressing the AF button and pressing shutter button to image capture (with Sigma 70mm f/2.8 prime).

Full Autofocus, Contrast-Detect AF

1.049 seconds

Time from pressing the AF button and pressing shutter button to image capture (with Sigma 70mm f/2.8 prime).

Pre-focused

0.335 second

Time to capture, after pressing and holding the AF button.

Full autofocus shutter lag using single-point (center) AF mode was excellent, at 0.105 second with our reference Sigma 70mm f/2.8 lens. Switching to auto-area AF mode increased lag slightly to 0.118 second, but that's still very fast for a consumer model. Enabling the flash increased the lag to 0.153 second, which is still very fast. Pre-focused shutter lag was good, at 0.097 second (pre-focused means half-pressing and holding down the shutter button before the final exposure). Continuous autofocus lag and Manual focus lag weren't much slower than prefocused, at 0.099 and 0.098 second respectively.

As expected, Live View mode shutter lag was a lot slower than using the optical viewfinder. Using phase-detect mode, full autofocus lag averaged about 1.2 seconds with our Sigma 70mm f/2.8 reference lens. That reduced to about a second when using contrast-detect mode. That's a little unusual as phase-detect AF is usually faster, but we don't change subject distance between iterations of our test, so the lens doesn't have to refocus much for contrast-detect mode, and the extra mirror flip required by phase-detect does take time. Prefocused, Live View mode shutter lag was 0.335 second, which is not bad for Live View mode.

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
0.31 second

Time per shot, averaged over 50 shots.

Single Shot mode
RAW

0.31 second

Time per shot, averaged over 17 shots.

Single Shot mode
RAW + LF JPEG

0.27 second

Time per shot, averaged over 10 shots.

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 Hi
Large Fine JPEG
0.18 second (5.62 frames per second);
30 frames total;
12 seconds to clear
Time per shot, averaged over buffer length of 30 frames. Once buffer is full, slows to an average of 0.30 second or 3.33 fps, with a lot of variation.

Continuous Hi
RAW

0.18 second (5.61 frames per second);
13 frames total;
17 seconds to clear

Time per shot, averaged over buffer length of 13 frames. Once buffer is full, slows to an average of 0.64 second or 1.57 fps, with a lot of variation.

Continuous Hi
RAW + LF JPEG

0.18 second (5.66 frames per second);
10 frames total;
17 seconds to clear

Time per shot, averaged over buffer length of 10 frames. Once buffer is full, slows to an average of 0.97 second or 1.03 fps, with a lot of variation.

Flash recycling

2.0 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 D-Range or NR can also affect cycle times and burst mode performance.

Shot-to-shot cycle times were very good for a consumer SLR, at about 0.31 second for JPEG or RAW files, and oddly, even faster at 0.27 second for RAW + L/F JPEG files. Continuous speeds were excellent for an entry-level consumer model, ranging from about 5.6 to 5.7 frames per second depending on the image file type in Continuous Hi mode. That's not quite as fast as Pentax's six frames per second specification, but still excellent nonetheless. A Continuous Lo speed is rated by Pentax at two fps, however we didn't test that mode.

Buffer depths were also very good for an entry-level model, at 30 Large/Fine JPEGs, 13 RAW and 10 RAW + L/F JPEG frames. (Note that our target image for this test is difficult to compress, so you'll likely get even longer JPEG bursts with more typical subjects.) The flash takes 2.0 seconds to recharge after a full-power shot, which is also very fast.

Download Speed

Windows Computer, USB 2.0

11,210 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 were very fast as well.

Bottom line, the Pentax K-r is very fast in just about every aspect of its operation. Continuous mode speeds are excellent, among the fastest in its class, and shutter lag and cycle times are quite fast, too. Buffer depths are also quite generous. All this means the Pentax K-r should do well in most shooting situations, including some sports.

Battery and Storage Capacity

Battery
Below average battery life for an SLR.

Operating Mode Number of Shots
Lithium-ion Rechargeable battery,
Optical Viewfinder
(CIPA standard)
470
4 x NiMH Rechargeable Batteries,
Optical Viewfinder
(CIPA standard)
400

The Pentax K-r ships with a rechargeable Li-ion battery and charger, but can also use four AA-type batteries with an optional D-BH109 AA battery holder. Battery life is below average for an SLR using the optical viewfinder with either type of rechargeable battery, and will most certainly be much less when using the LCD in Live View mode. We strongly recommend you pick up a spare Lithium-ion battery pack (or the AA battery holder, a couple sets of rechargeable NiMH AA batteries and a good quality charger), for extended outings or if you plan to use Live View or shoot video a lot.

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 Pentax K-r accepts SD/SDHC memory cards and SDXC cards with firmware 1.01; no card is included with the camera. The Pentax K-r operating manual doesn't specify a minimum Speed Class for shooting HD video, but since the K-r uses relatively inefficient Motion JPEG encoding for movies, you'll need at least a Speed Class 6 card for recording best quality 720p movies.

Image Capacity with
1GB Memory Card
Fine
(***)
Normal
(**)
Basic
(*)
RAW RAW
+ LF JPG
4,288 x 2,848
Images
(Avg size)
140
7.3 MB
247
4.1 MB
487
2.1 MB
49
20.9 MB
36
28.4 MB
Approx.
Compression
5:1
9:1
17:1
0.9:1
-
3,936 x 2,624
Images
(Avg size)
166
6.2 MB
292
3.5 MB
569
1.8 MB
-
-
Approx.
Compression
5:1
9:1
17:1
-
-
3,072 x 2,048
Images
(Avg size)
271
3.8 MB
472
2.2 MB
903
1.1 MB
-
-
Approx.
Compression
5:1
9:1
17:1
-
-
1,728 x 1,152
Images
(Avg size)
808
1.3 MB
1,396
733 KB
2,560
400 KB
-
-
Approx.
Compression
5:1
8:1
15:1
-
-

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

 

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