Pentax K20D Review - Performance

Very good to average speed for a prosumer 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	0.3 second	How long it takes to turn off.
Buffer clearing time Large Super Fine JPEG	10 seconds (after 20 LSF 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.
Buffer clearing time Small Basic JPEG	3 seconds (after 20 SB JPEGs)
Buffer clearing time RAW	17 seconds (after 11 RAW frames)
Buffer clearing time RAW + JPEG	16 seconds (after 8 RAW + JPEG frames)

The Pentax K20D's start-up and shutdown times were very fast; difficult to measure. Buffer clearing can be a bit slow due to the large file sizes, and depends on the image size and quality, burst length and how fast the card can be written to.

Mode Switching
Play to Record, first shot	0.5 second	Time until first shot is captured.
Record to Play	1.3 seconds	Time to display a large/super fine file immediately after capture.
Display recorded image	0.4 second	Time to display a large/fine file already on the memory card.

Mode switching is about average for an SLR, though switching from Record to Play was a bit on the slow side.

Shutter Response (Lag Time)
Full Autofocus Optical Viewfinder	0.174 second	Time from fully pressing shutter button to image capture using Sigma 70mm f/2.8 lens.
Full Autofocus with flash enabled Optical Viewfinder	0.241 second	Time from fully pressing shutter button to image capture with built-in flash enabled in P-TTL Auto mode.
Full Autofocus Live View	n/a	Time from fully pressing shutter button to image capture. Not possible in Live View mode, since shutter button does not perform autofocus. AF button must be used to autofocus first.
Pre-focused Live View	0.659 second	Time from fully pressing shutter button to image capture using Sigma 70mm f/2.8 lens in Live View mode.
Pre-focused with flash enabled Live View	2.395 seconds	Time from fully pressing shutter button to image capture with built-in flash enabled in P-TTL Auto mode in Live View mode.
Pre-focused Optical Viewfinder	0.089 second	Time to capture, after half-pressing and holding shutter button.
Continuous AF Optical Viewfinder	0.091 second	Continuous-servo AF mode on the K20D forces release priority, so while shutter response is faster, the resulting image may not be in focus.
Manual focus Optical Viewfinder	0.090 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 shutter response is fast for an SLR, at 0.174 second. With the flash enabled, shutter lag increased to 0.241 second, which is still pretty good. Pre-focus time was very fast, at 0.089 second (pre-focusing means half-pressing and holding down the shutter button before the final exposure). Continuous AF mode and Manual AF mode were about the same speed as pre-focused. Shutter lag in Live View mode was quite a bit slower, at 0.659 second, and that doesn't include autofocus because the AF button must be pressed to autofocus (pressing the shutter button does not autofocus in Live View mode). Enabling the flash in Live View mode resulted in a very long 2.395s delay.

Cycle Time (shot-to-shot)
Single Shot mode Large Super Fine JPEG	0.39 second	Time per shot, averaged over 20 shots, 8 seconds to clear.
Single Shot mode Small Basic JPEG	0.37 second	Time per shot, averaged over 20 shots, 2 seconds to clear.
Single Shot mode RAW	0.36 second	0.36 second for 11 shots, then average of 1.13 seconds for the next 9 shots, 17 seconds to clear.
Single Shot mode RAW + JPEG	0.36 second	0.36 second for 8 shots, then average of 1.83 seconds for the next 12 shots, 16 seconds to clear.
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 mode Large Super Fine JPEG	0.36 second (2.75 frames per second); >20 frames total; 10 seconds to clear	Time per shot, averaged over 20 shots.
Continuous HI mode Small Basic JPEG	0.35 second (2.83 frames per second); >20 frames total; 3 seconds to clear	Time per shot, averaged over 20 shots.
Continuous HI mode RAW	0.36 second (2.82 frames per second); 15 frames total; 15 seconds to clear	0.36 seconds for the first 15 frames, then slows to an average of 1.45 seconds (0.69 fps) for the remaining 5 shots.
Continuous HI mode RAW + JPEG	0.35 second (2.89 frames per second); 8 frames total; 15 seconds to clear	0.35 seconds for the first 8 frames, then slows to an average of 1.84 seconds (0.54 fps) for the remaining 12 shots.
Continuous Burst mode 1.6 MP JPEG	0.05 second (22.22 frames per second); >20 frames total; 7 seconds to clear	Time per shot, averaged over 20 shots.
Flash recycling	3.05 seconds	Flash at maximum output.
*Note: Buffer clearing times measured with a SanDisk Extreme III SD 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 NR can also affect cycle times and burst mode performance.

Shot-to-shot cycle times are very good, at about 0.39 seconds for large/super fine JPEGs, and the camera was able to capture 20 frames before slowing down. RAW mode was 0.36 second per shot, but the K20D had to slow down after 11 frames to flush to the card. Continuous Hi mode speed is a bit below average (not bad for 14.5MP files though), at about 2.75 frames per second, and the buffer didn't appear to fill after 20 large/super fine JPEGs. RAW Continuous Hi mode managed 2.82 frames per second for 15 frames before slowing. The Continuous Burst mode was incredibly fast, at over 22 frames-per-second (!), but images are only 1.6-megapixels JPEGs in this mode. The flash takes 3.05 seconds to recharge after a full-power shot, which is very good.

Download Speed
Windows Computer, USB 2.0	8,004 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 very fast.

Bottom line, the Pentax K20D is a very responsive camera, able to handle average family shots as well as some fast action (but see the section regarding real-world AF tracking performance in the User Report). The unique 22 frames-per-second burst mode is incredibly fast, but resolution is only 1.6-megapixels, so this mode has limited usefulness.

Battery
Average battery life for a lithium-ion powered SLR.

Operating Mode	Number of Shots
Optical Viewfinder (CIPA standard)	530
Live View (CIPA standard)	Not Available

The Pentax K20D uses a custom lithium-ion battery for power, and ships with a charger. Battery life is about average for an SLR (below average for a prosumer model), so we recommend you pick up a spare battery and keep it freshly charged and on-hand for extended outings. Pentax doesn't publish battery life for Live View mode, but you can expect it to be lower.

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 K20D accepts SD/SDHC cards, though no card is included.

Image Capacity vs Resolution/Quality 1GB Memory Card		SuperFine (Premium)	Fine (Best)	Normal (Better)	Basic (Good)	RAW	RAW+ JPG
4672 x 3104	Images (Avg size)	69 14.8 MB	120 8.5 MB	217 4.7 MB	421 2.4 MB	41 25 MB	38 26.9 MB
4672 x 3104	Approx. Compression	3:1	5:1	9:1	18:1	0.9:1	-
3872 x 2592	Images (Avg size)	103 9.9 MB	173 5.9 MB	303 3.4 MB	632 1.6 MB	-	-
3872 x 2592	Approx. Compression	3:1	5:1	9:1	19:1	-	-
3008 x 2000	Images (Avg size)	181 5.7 MB	292 3.5 MB	503 2.0 MB	938 1.1 MB	-	-
3008 x 2000	Approx. Compression	3:1	5:1	9:1	17:1	-	-
1814 x 1216	Images (Avg size)	472 2.2 MB	755 1.4 MB	1,264 810 KB	2,294 446 KB	-	-
1814 x 1216	Approx. Compression	3:1	5:1	8:1	15:1	-	-

The table above shows the approximate capacity of a 1GB card, file sizes and compression ratios at each image size/quality setting. We strongly recommend buying a large capacity SD/SDHC memory card at least a 2GB card, preferably a 4 or 8GB one, to give yourself extra space for extended outings or if you plan on shooting in RAW mode. (Check the shopping link above. Cards are really cheap these days, so there's no reason to skimp.)