• APS-C 369.7mm2
  • 14.2 megapixels
  • ISO 200 - 12,800
  • Medium format 1,436.6mm2
  • 51.4 megapixels
  • ISO 100 - 204,800
  • Detailed specifications
  • Sony Alpha DSLR-A550
  • Pentax 645Z
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Prices:   Compare Prices
Manufacturer URL: Manufacturer website Manufacturer website
Predecessor:   Pentax 645D
645D vs 645Z
Successor:    
General
Model Number: DSLR-A550 645Z
Alternate Model Number(s):    
Camera Format: SLR Pro SLR
Currently Manufactured: No Yes
Retail Price: $1049.99 $8499.95
Street Price: $859.40 $4,845.43
Date Available: 2009-10-08 2014-06-15
Tripod Mount: Yes Yes
Weight: 32.2 oz (912 g)
includes batteries, kit lens
54.9 oz (1,555 g)
includes batteries
Size: 5.4 x 4.1 x 3.3 in.
(137 x 104 x 84 mm)
6.1 x 4.6 x 4.8 in.
(156 x 117 x 123 mm)
Waterproof: No No
Waterproof Depth: n/a n/a
Image Sensor
Sensor Type: CMOS CMOS
Sensor Manufacturer: Sony Sony
Effective Megapixels: 14.2 51.4
Sensor Format: APS-C Medium format
Sensor size: 369.72mm2 (23.7mm x 15.6mm) 1436.64mm2 (43.80mm x 32.80mm)
Approximate Pixel Pitch: 5.16 microns 5.31 microns
Focal Length Multiplier: 1.5x 0.8x
Aspect Ratio: 3:2, 16:9 4:3
Color Filter Type: RGBG RGBG
Anti Aliasing Filter: Fixed None
Self-Cleaning: Yes Yes
Sensor shift image stabilization: Yes No
On-Sensor Phase Detect: No No
DxO Sensor Score: 66 101
DxO Color Depth Score (bits): 21.9 26.0
DxO Dynamic Range Score (evs): 11.8 14.7
DxO Maximum Effective ISO Score (iso): 807 4,505
Image Capture
Image Resolution: 4592 x 3056 (14.0 MP, 3:2),
4592 x 2576 (11.8 MP, 16:9),
3344 x 2224 (7.4 MP, 3:2),
3344 x 1872 (6.3 MP, Other),
2288 x 1520 (3.5 MP, Other),
2288 x 1280 (2.9 MP, Other)
8256 x 6192 (51.1 MP, 4:3),
6192 x 5184 (32.1 MP, Other),
5376 x 4032 (21.7 MP, 4:3),
1920 x 1440 (2.8 MP, 4:3)
Image File Format: JPEG, RAW JPEG, 14-bit PEF / DNG RAW, TIFF
Continuous-mode frames/second: 6.7 3.1
Video Capture
Can take movies: No Yes
Movie Resolution: 1920x1080 (60i/​50i/​30p/​25p/​24p)
1280x720 (60p/​50p/​30p/​25p/​24p)
Movie File Format:   MOV (MPEG-4 AVC/H.264) with stereo sound; Motion JPEG (AVI) for Interval Movie Record
Composite Video Out: No No
NTSC/PAL Switchable Video: n/a n/a
Video Usable as Viewfinder: n/a n/a
HD Video Out: Yes Yes
HD Video Connection: HDMI HDMI
Lens & Optics
Lens Mount: Sony Alpha (Minolta A) Pentax 645 bayonet
Lens: Sony 18-55mm f/3.5-5.6 DT SAM n/a
Focal Length (35mm equivalent): 27 - 83mm  
Focal Length (actual): 18 - 55mm  
Zoom Ratio: 3.00x  
Aperture Range: f/3.5 - 22 (W), f/5.6 - ?? (T)  
Integrated ND Filter: No No
Normal Focus Range:    
Macro Focus Range:    
Filter Thread: 55.0mm n/a
Thread Type: n/a n/a
Optical Image Stabilization: No No
Digital Zoom: No
Digital Zoom Values: n/a  
Auto Focus
Auto Focus: Yes Yes
Auto Focus Type: 9-point TTL phase detection (one cross-type sensor) with eye-start AF; Wide, Spot, Local modes 27-point SAFOX 11+ Phase Difference Detection (25 cross type focus points in the center): Spot, Select, Expanded Area AF (S, M, L), Zone Select, Auto (27 AF Points)
Auto Focus Assist Light? Yes No
Manual Focus: Yes Yes
Viewfinder
Viewfinder: Optical / LCD Optical / LCD
Viewfinder Type: SLR type; eye-level pentamirror, 95% coverage, 0.80x mag., 19mm eyepoint, -2.5 to +1.0 diopter Trapezoid prism finder w/ interchangeable Natural-Bright-Matte focusing screen; Coverage: ~98%; Magnification: ~0.62x (55mmF2.8 at infinity), ~0.85x (75mmF2.8 at infinity); Diopter: -3.5 m to + 2.0 m-1; Eye Relief: ~21 mm (from view window), ~24.1 mm (from center of lens)
Focus Peaking: No Yes
EVF Resolution: n/a n/a
Viewfinder Magnification (35mm equivalent): 0.53x 0.78x
Viewfinder Magnification (nominal/claimed): 0.80x 0.62x
Display
Eye-level Viewfinder: Yes Yes
Rear Display: Yes Yes
Rear Display Size (inches): 3.0 3.2
Rear Display Resolution: 921,600 dots 1,036,800 dots (345,600 px)
Touchscreen: No No
Articulating Screen: Yes Yes
Tilt Swivel Screen: No
Selfie Screen: No
Max Playback Zoom: 14.0x 16.0x
Top Deck Display: No Yes
Exposure
Maximum ISO (native): 12800 204800
Minimum ISO (native): 200 100
ISO Settings: Auto (200-1600), 200, 400, 800, 1600, 3200, 6400, 12800 Auto, 100-204800 in 1, 1/2 or 1/3EV steps
Auto ISO Mode: Yes Yes
White Balance Settings: Auto, Daylight, Shade, Cloudy, Incandescent, Fluorescent, Flash, Custom Auto, Multi Auto, Daylight, Shade, Cloudy, Fluorescent Light (D: Daylight Color, N: Daylight White, W: Cool White, L: Warm White), Tungsten, Flash, CTE; Manual mode(s): Manual (up to 3 settings can be saved), Color Temperature (up to 3 settings can be saved), Copying the white balance settings of a captured image possible
Shutter Speed Range: 1/4000 - 30 sec 1/4000 - 30 sec
Bulb Mode: Yes Yes
Exposure Compensation: +/- 2.0EV in 0.3EV steps +/- 5.0EV in 0.3EV steps
Metering Modes: 40-segment Multi Segment, Center-weighted, Spot; (1200 zone evaluative metering in Live View) 86K-pixel RBG sensor: Multi-segment metering, Center-weighted metering, Spot metering
Program Auto Exposure: Yes Yes
Aperture Priority: Yes Yes
Shutter Priority: Yes Yes
Full Manual Exposure: Yes Yes
Creative Exposure Modes: Portrait, Landscape, Macro, Sports, Sunset, Night Portrait/Night View Sensitivity Priority, Shutter & Aperture Priority; HDR Capture: Auto, Type1, Type2, Type3, Exposure Bracket Value adjustable, Auto Align (automatic composition correction function) available; Custom Image: Bright, Natural, Portrait, Landscape, Vibrant, Radiant, Muted, Bleach Bypass, Reversal Film, Monochrome, Cross Processing (Random, Preset 1-3, Favorite 1-3)
Self Timer: 2 or 10 seconds 2 or 12 seconds
Time Lapse (intervalometer):   Yes
High Resolution Composite: No No
Flash
Built-in Flash: Yes No
Flash Modes: Auto, Fill-flash, Rear sync, Wireless, High-Speed sync, Slow sync, Red-eye reduction: On/Off P-TTL; high-speed sync, wireless sync supported with compatible flash unit
Flash Guide Number (ISO 100): 12.0 m / 39.4 ft. n/a
Flash Range Description: Lens dependent n/a
Max Flash Sync: 1/160 1/125
Flash Exposure Compensation: +/- 2.0 EV in 0.3EV steps -2 to +1 EV
External Flash Connection: Hot shoe Hot shoe, X-sync socket
Built-In Wireless Flash Control: Full TTL exposure  
Image Storage
Usable Memory Types: MS Duo / MS PRO Duo / SD / SDHC SD / SDHC / SDXC
UHS Support:   UHS-I
Other Memory:    
Dual Card Slots: No Yes
RAW Capture Support: Yes Yes
Uncompressed Format: RAW 14-bit PEF / DNG RAW, TIFF
Movie File Format:   MOV (MPEG-4 AVC/H.264) with stereo sound; Motion JPEG (AVI) for Interval Movie Record
Included Memory:   No memory included
Included Memory Type:    
Connectivity
Built-In Wi-Fi: No No
NFC: 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 3.0 Super Speed
PictBridge Compliant: Yes No
DPOF Compliant: Yes No
Remote Control: Yes Yes
Remote Control Type: Optional Wireless or Wired Optional wired or wireless
Connections (extended): DC input, mini-HDMI, Wired Remote Micro (Type-D) HDMI, DC input, Stereo microphone jack, wired remote socket
Performance Timing
Cycle time for JPEG shooting in single shot mode (seconds per frame, max resolution): 0.41 0.35
Cycle time for RAW shooting in single shot mode (seconds per frame): 0.41 0.33
Buffer size for RAW shooting in single shot mode (frames): 19 10
Cycle time for RAW+JPEG shooting in single shot mode (seconds per shot):   0.33
Camera penalizes early shutter press? No Yes
JPEG shooting speed in burst mode (fps, max resolution): 6.7 3.1
Buffer size for JPEG shooting in burst mode (frames, max resolution): 15 12
RAW shooting speed in burst mode (fps):   3.1
Buffer size for RAW shooting in burst mode (frames):   10
RAW+JPEG shooting speed in burst mode (fps):   3.1
Buffer Size for RAW+JPEG shooting in burst mode (frames):   10
Shutter lag (full AF, wide/mid): 0.18 seconds 0.16 seconds
Shutter lag (full AF, tele):    
Shutter lag (full AF, live view - DSLR):   1.17 seconds
Shutter lag (prefocused, live view - DSLR):   0.385 seconds
Shutter Lag (manual focus): 0.178 seconds 0.117 seconds
Shutter lag (full AF, with flash): 0.22 seconds  
Shutter Lag (prefocused): 0.074 seconds 0.112 seconds
Shutter Lag (notes): Quick AF Live View shutter lag: 0.188s OVF: Full AF lag, wide-area mode = 0.170s Live View: Full AF lag, Spot AF mode = 1.174s Prefocused = 0.385s
Startup Time: 0.5 seconds 1.5 seconds
Play -> Record Time: 0.4 seconds 0.7 seconds
Flash cycle time, full power: 3.5 seconds  
Power
Battery Life, Stills (CIPA Rating Monitor/Live View):    
Battery Life, Still (CIPA Rating OVF/EVF): 950 shots 650 shots
Battery Life, Video:    
Battery Form Factor: Proprietary NP-FM500H Proprietary D-LI90
Usable Battery Types: Lithium-ion rechargeable Lithium-ion rechargeable
Batteries Included: 1 x Proprietary NP-FM500H 1 x Proprietary D-LI90 Lithium-ion rechargeable
Battery Charger Included (dedicated charger or AC/USB adapter): Yes Yes
Dedicated Battery Charger Included: Yes
Internal Charging Supported: No
Software
Included Software: Software/USB Driver CD-ROM  
OS Compatibility: Windows 2000/XP/Vista, Mac OS X (v. 10.13+)  
Miscellaneous
Notes & Features: Exmore CMOS Sensor, Variable-angle LCD, SteadyShot In-body Sensor-shift Image Stabilization, Live View, Auto HDR, D-Range Optimizer (Auto, Level 1-5), HDMI Output, 7 fps (AF/AE Locked). New 51.4MP AA-filterless CMOS sensor, PRIME III processor, 27-point SAFOX 11 AF, 86K RGB metering, Full HD video up to 60i, tilting LCD monitor with Live View, 3fps full-res continuous burst mode.