• APS-C 369.7mm2
  • 12.4 megapixels
  • ISO 200 - 6400
  • APS-C 369.7mm2
  • 16.1 megapixels
  • ISO 100 - 16,000
  • Detailed specifications
  • Pentax K-x
  • Sony Alpha SLT-A37
Links
Prices:    
Manufacturer URL: Manufacturer website Manufacturer website
Predecessor: Pentax K2000
K2000 vs K-x
 
Successor: Pentax K-r
K-x vs K-r
 
General
Model Number: K-x A37
Alternate Model Number(s):    
Camera Format: SLR SLR
Currently Manufactured: No No
Retail Price: $649.95 $599.99
Street Price: $701.76  
Date Available: 2009-10-15 2012-06-15
Tripod Mount: Yes Yes
Weight: 27.9 oz (791 g)
includes batteries, kit lens
25.6 oz (726 g)
includes batteries, kit lens
Size: 4.8 x 3.6 x 2.7 in.
(122 x 92 x 69 mm)
4.9 x 3.6 x 3.3 in.
(124 x 92 x 85 mm)
Waterproof: No No
Waterproof Depth: n/a n/a
Image Sensor
Sensor Type: CMOS CMOS
Sensor Manufacturer:   Sony
Effective Megapixels: 12.4 16.1
Sensor Format: APS-C APS-C
Sensor size: 369.72mm2 (23.7mm x 15.6mm) 369.72mm2 (23.7mm x 15.6mm)
Approximate Pixel Pitch: 5.53 microns 4.82 microns
Focal Length Multiplier: 1.5x 1.5x
Aspect Ratio: 3:2 3:2
Color Filter Type: RGBG RGBG
Anti Aliasing Filter: Fixed Fixed
Self-Cleaning: Yes Yes
Sensor shift image stabilization: Yes Yes
On-Sensor Phase Detect: No No
DxO Sensor Score: 72 75
DxO Color Depth Score (bits): 22.8 23.3
DxO Dynamic Range Score (evs): 12.5 12.9
DxO Maximum Effective ISO Score (iso): 811 799
Image Capture
Image Resolution: 4288 x 2848 (12.2 MP, Other),
3936 x 2624 (10.3 MP, 3:2),
3072 x 2048 (6.3 MP, 3:2),
1728 x 1152 (2.0 MP, 3:2)
4912 x 3264 (16.0 MP, 3:2),
4912 x 2760 (13.6 MP, 16:9),
3568 x 2368 (8.4 MP, Other),
3568 x 2000 (7.1 MP, 16:9),
2448 x 1624 (4.0 MP, Other),
2448 x 1376 (3.4 MP, 16:9),
12416 x 1856 (23.0 MP, Other),
5536 x 2160 (12.0 MP, Other),
8192 x 1856 (15.2 MP, Other),
3872 x 2160 (8.4 MP, Other),
7152 x 1080 (7.7 MP, Other),
4912 x 1080 (5.3 MP, Other),
1920 x 1080 (2.1 MP, 16:9)
Image File Format: JPEG (EXIF 2.21), 12-bit RAW (.PEF, .DNG) JPEG, MPO, RAW (12-bit ARW 2.3), RAW+JPEG
Continuous-mode frames/second: 4.3 5.5
Video Capture
Can take movies: Yes Yes
Movie Resolution: 1280x720 (24)
640x416 (24)
1920x1080 (60i(FH)/​24p(FX)/​24p(FH))
1440x1080 (30p)
640x480 (30p)
Movie File Format:   AVCHD 1.0/MP4 (Audio: Dolby Digital (AC-3)/MPEG-4 AAC-LC)
Composite Video Out: Yes No
NTSC/PAL Switchable Video: Yes n/a
Video Usable as Viewfinder: No n/a
HD Video Out: No Yes
HD Video Connection: HDMI
Lens & Optics
Lens Mount: Pentax K (KA/KAF/KAF2/3) Sony Alpha (Minolta A)
Lens: smc Pentax DA L 18-55mm f/3.5-5.6 AL Sony 18-55mm f/3.5-5.6 DT SAM
Focal Length (35mm equivalent): 27 - 84mm 27 - 83mm
Focal Length (actual): 18 - 55mm 18 - 55mm
Zoom Ratio: 3.00x 3.06x
Aperture Range: f/3.5 - 22 (W), f/5.6 - 38 (T) f/3.5 - 22 (W), f/5.6 - 36 (T)
Integrated ND Filter: No No
Normal Focus Range:   25 cm to Infinity
9.8 in to Infinity
Macro Focus Range:    
Filter Thread: 52.0mm 55.0mm
Thread Type: n/a n/a
Optical Image Stabilization: No No
Digital Zoom: No Yes
Digital Zoom Values: n/a Up to 2x Precision, Up to 2x Clear Image Zoom, 1.4x (8.4MP) or 2.0x (4MP) Smart Zoom
Auto Focus
Auto Focus: Yes Yes
Auto Focus Type: SAFOX VIII TTL phase-detect 11 point (9 cross) AF: 11 pt auto, 5 pt auto, AF pt select, center/spot Phase Detection: 15 points (3 points cross type); Wide (auto, 15 points), Zone, Spot, Local; Enhanced Object Tracking
Auto Focus Assist Light? Yes Yes
Manual Focus: Yes Yes
Viewfinder
Viewfinder: Optical / LCD EVF / LCD
Viewfinder Type: SLR type; fixed eye-level pentamirror, 96% coverage, 0.85x mag., -2.5 to +1.5 diopter EVF type; 1.1cm (0.43") 1.15M-dot LCD (380K-dot time-multiplexed RGB), 100% coverage, 1.1x magnification, 19mm eyepoint, -4 to +4 diopter
Focus Peaking: No Yes
EVF Resolution: n/a  
Viewfinder Magnification (35mm equivalent): 0.57x 0.73x
Viewfinder Magnification (nominal/claimed): 0.85x 1.10x
Display
Eye-level Viewfinder: Yes Yes
Rear Display: Yes Yes
Rear Display Size (inches): 2.7 2.6
Rear Display Resolution: 230,000 dots 230,400 dots (76,800 px)
Touchscreen: No No
Articulating Screen: No Yes
Tilt Swivel Screen: No
Selfie Screen: No
Max Playback Zoom: 16.0x 11.8x
Top Deck Display: No No
Exposure
Maximum ISO (native): 6400 16000
Minimum ISO (native): 200 100
ISO Settings: Auto (200-6400), 100, 200, 400, 800, 1600, 3200, 6400; expandable to 12800 Auto (100-3200), 100, 200, 400, 800, 1600, 3200, 6400, 12800, 16000; (Multi-frame NR mode up to ISO 25600)
Auto ISO Mode: Yes Yes
White Balance Settings: Auto, Daylight, Shade, Cloudy, Tungsten, Fluorescent (D, N, W, L), Flash, Custom Auto, Daylight, Shade, Cloudy, Incandescent, Fluorescent (Warm, Cool, Day, Daylight), Flash, Custom, Color Temp/Filter (2500-9900K with 15-step Magenta/Green compensation)
Shutter Speed Range: 1/6000 - 30 sec 1/4000 - 30 sec
Bulb Mode: Yes Yes
Exposure Compensation: +/- 2.0EV in 0.3EV steps +/- 3.0EV in 0.3EV steps
Metering Modes: 16-segment Multi, Center-weighted, Spot 1200-zone Evaluative, Center-weighted, Spot
Program Auto Exposure: Yes Yes
Aperture Priority: Yes Yes
Shutter Priority: Yes Yes
Full Manual Exposure: Yes Yes
Creative Exposure Modes: Auto Picture (Portrait, Landscape, Macro, Action, Night Scene Portrait, Picture (Portrait, Landscape, Macro, Action, Night Scene Portrait, Standard Flash Off), Scene (Night Scene, Surf & Snow, Food, Sunset, Kids, Pet, Candlelight, Museum, Stage Lighting [JPG], Night Snap [JPG]), Sensitivity Priority Sweep Panorama, 3D Sweep Panorama, Portrait, SportsAction, Macro, Landscape, Sunset, Night view, Hand-held Twilight (6 shot layering), Night Portrait, Picture Effect (Posterization (color/B/W), Pop Color, Retro Photo, Partial color (R/G/B/Y), High Contrast Monochrome, Toy Camera (Normal/Cool), Soft High-key, Soft Focus (Hi/Mid/Lo), HDR Painting (Hi/Mid/Lo), Miniature (7 Settings))
Self Timer: 2 or 12 seconds 2 or 10 seconds
Time Lapse (intervalometer):    
High Resolution Composite: No No
Flash
Built-in Flash: Yes Yes
Flash Modes: On, off, redeye, slow sync, slow sync w redeye, slow sync w trailing curtain, wireless Auto, Off, Fill-flash, Rear sync, Wireless, High-Speed sync, Slow sync, Red-eye reduction: On/Off
Flash Guide Number (ISO 100): 11.3 m / 37.1 ft. 10.0 m / 32.8 ft.
Flash Range Description: Depends on lens Lens dependent
Max Flash Sync: 1/180 1/160
Flash Exposure Compensation: -2 to +1 EV in 0.5EV steps +/- 2.0 EV in 0.3EV steps
External Flash Connection: Hot Shoe Hot shoe
Built-In Wireless Flash Control: Full TTL exposure  
Image Storage
Usable Memory Types: SD / SDHC MS PRO Duo / SD / SDHC / SDXC
UHS Support:    
Other Memory:    
Dual Card Slots: No No
RAW Capture Support: Yes Yes
Uncompressed Format: 12-bit RAW (.PEF, .DNG) RAW (12-bit ARW 2.3), RAW+JPEG
Movie File Format:   AVCHD 1.0/MP4 (Audio: Dolby Digital (AC-3)/MPEG-4 AAC-LC)
Included Memory: No memory included  
Included Memory Type:    
Connectivity
Built-In Wi-Fi: No No
NFC: No No
Bluetooth: No No
Built-In GPS: No No
Microphone Jack: No Yes
Headphone Jack: No No
External Connections: USB 2.0 High Speed USB 2.0 High Speed
PictBridge Compliant: No Yes
DPOF Compliant: Yes Yes
Remote Control: Yes Yes
Remote Control Type: Optional IR Optional Wired (RM-S1AM/RM-L1AM)
Connections (extended): AC adapter available Type-C Mini HDMI (BRAVIA Sync, PhotoTV HD); Wired Remote Terminal, 3.5mm External Stereo Micophone Jack, DC Input
Performance Timing
Cycle time for JPEG shooting in single shot mode (seconds per frame, max resolution): 0.39 0.47
Cycle time for RAW shooting in single shot mode (seconds per frame): 0.43 0.45
Buffer size for RAW shooting in single shot mode (frames): 10 2
Cycle time for RAW+JPEG shooting in single shot mode (seconds per shot):    
Camera penalizes early shutter press? No No
JPEG shooting speed in burst mode (fps, max resolution): 4.3 5.5
Buffer size for JPEG shooting in burst mode (frames, max resolution): 25 10
RAW shooting speed in burst mode (fps):    
Buffer size for RAW shooting in burst mode (frames):    
RAW+JPEG shooting speed in burst mode (fps):    
Buffer Size for RAW+JPEG shooting in burst mode (frames):    
Shutter lag (full AF, wide/mid): 0.10 seconds 0.11 seconds
Shutter lag (full AF, tele):    
Shutter lag (full AF, live view - DSLR):    
Shutter lag (prefocused, live view - DSLR):    
Shutter Lag (manual focus): 0.082 seconds 0.080 seconds
Shutter lag (full AF, with flash): 0.23 seconds 0.32 seconds
Shutter Lag (prefocused): 0.082 seconds 0.057 seconds
Shutter Lag (notes): Live View: Phase-detect Full AF: 0.448s Contrast-detect Full AF: 2.567s Prefocused: 0.427s Full AF lag, Wide-area mode = 0.124s
Startup Time: 0.6 seconds 0.9 seconds
Play -> Record Time: 0.2 seconds 0.9 seconds
Flash cycle time, full power: 3.3 seconds 2.5 seconds
Power
Battery Life, Stills (CIPA Rating Monitor/Live View):    
Battery Life, Still (CIPA Rating OVF/EVF): 420 shots (NiMH AA) 450 shots
Battery Life, Video:    
Battery Form Factor: 4 x AA Proprietary
Usable Battery Types: Lithium, Alkaline disposables; NiMH rechargeables NP-FW50 Lithium-ion rechargeable
Batteries Included: 4 x AA Alkaline disposables 1 x Proprietary NP-FW50 Lithium-ion rechargeable
Battery Charger Included (dedicated charger or AC/USB adapter): No Yes
Dedicated Battery Charger Included:
Internal Charging Supported:
Software
Included Software: CD-ROM Sony Software CD-ROM
OS Compatibility: Windows XP/Vista/7, MacOS-X 10.3+ Windows XP SP3/Vista SP2/7, Mac OS X (v.10.3 +)
Miscellaneous
Notes & Features: Sensor-shift shake reduction, 720p HD video capture, Live View with face detection. Available in black or white. Limited edition colors of red and navy will become available at select locations to be announced. SteadyShot INSIDE Sensor-shift Image Stabilization (up to 4 EV correction), Full HD 1080i60 Video, Up to 7 fps Burst Mode (Tele-zoom Continuous Advance Priority AE), Enhanced Object Tracking AF, 2x Clear Image Digital Zoom, Auto Portrait Framing.