Sony Alpha 55 Specs, Sensor Size & Crop Factor

Q: What is the crop factor of the Sony Alpha 55?

The Sony Alpha 55 has a crop factor of 1.52× relative to 35 mm full frame (diagonal 28.4 mm vs 43.3 mm).

1.52×

Crop factor

23.5×16.0 mm

Sensor size

375 mm²

Area · 43% of full frame

16.2 MP

Resolution

4.81 µm

Pixel pitch

f/7.2

Diffraction-limited aperture

2010

Release year

Specifications#

Brand: Sony
Model: Alpha 55
Also known as: SLT-A55, SLT-A55V, Sony SLT-A55, Sony SLT-A55V
Camera type: DSLR
Released: 2010-01-01
Lens mount: Sony / Minolta A-mount
Sensor size: 23.5 × 16.0 mm (APS-C)
Crop factor: 1.52×
Resolution: 16.2 MP (4,884 × 3,317 px)
Continuous shooting: 10 fps
Weight: 441 g (15.6 oz)
Sensor: APS-C CMOS Sensor
Storage: SD/SDHC/SDXC/Memory Stick Pro Duo
Viewfinder: EVF, 100% coverage, 1.10× magnification
AF points / area: 15-point (12 line, 3 cross) phase-detection AF system
Metering: TTL full aperture exposure metering system; 1200-zone evaluative
Exposure modes: Programmed AE (AUTO, AUTO – Flash Off, P), Aperture priority, Shutter priority, Manual, Scene selection
Shutter: Electronically controlled, Vertical-traverse, Focal-plane Shutter
Flash: GN 10 at ISO 100
Battery: NP-FW50 Lithium-ion battery rechargeable battery
Dimensions: 124 × 92 × 85 mm
Lens: Interchangeable, A-mount
Drive: 10 FPS / 6 FPS

Specifications merged from Wikipedia, Wikidata, Lensfun and openMVG. Spot an error? Tell us.

Sensor size compared#

The Sony Alpha 55 sensor (highlighted) drawn to scale against common formats. Its area is 43% of a full-frame sensor, which collects about 1.2 stops less total light at the same exposure.

Focal length equivalents & field of view#

Multiply any focal length by 1.52 to get the full-frame field of view. Angles are for a rectilinear lens focused at infinity.

Lens on this camera	Full-frame equivalent	Horizontal	Vertical	Diagonal
8 mm	12 mm	111.5°	89.9°	121.2°
10 mm	15 mm	99.2°	77.2°	109.7°
12 mm	18 mm	88.8°	67.2°	99.6°
14 mm	21 mm	80.0°	59.4°	90.8°
16 mm	24 mm	72.6°	53.0°	83.2°
18 mm	27 mm	66.3°	47.8°	76.6°
20 mm	30 mm	60.9°	43.5°	70.8°
24 mm	37 mm	52.2°	36.8°	61.2°
28 mm	43 mm	45.5°	31.8°	53.8°
35 mm	53 mm	37.1°	25.7°	44.2°
40 mm	61 mm	32.7°	22.6°	39.1°
50 mm	76 mm	26.4°	18.1°	31.7°
56 mm	85 mm	23.7°	16.2°	28.5°
70 mm	107 mm	19.1°	13.0°	22.9°
85 mm	129 mm	15.7°	10.7°	19.0°
100 mm	152 mm	13.4°	9.1°	16.2°
135 mm	206 mm	9.9°	6.8°	12.0°
200 mm	305 mm	6.7°	4.6°	8.1°
300 mm	457 mm	4.5°	3.0°	5.4°
400 mm	609 mm	3.4°	2.3°	4.1°
600 mm	914 mm	2.2°	1.5°	2.7°
800 mm	1218 mm	1.7°	1.1°	2.0°

Depth of field table#

Total depth of field at each subject distance, using a circle of confusion of 19.7 µm (the 0.030 mm full-frame standard scaled by the crop factor). Detailed tables: 24 mm f/1.8, 24 mm f/2.8, 35 mm f/1.8, 35 mm f/2.8, 50 mm f/1.8, 50 mm f/2.8.

Focal	Aperture	50.0 cm	1.00 m	2.00 m	3.00 m	5.00 m	10.0 m	Hyperfocal
14 mm	f/1.8	8.9 cm	36.8 cm	1.65 m	4.58 m	48.3 m	∞	5.54 m
14 mm	f/2.8	13.9 cm	60.1 cm	3.25 m	17.1 m	∞	∞	3.57 m
14 mm	f/4	20.3 cm	94.0 cm	8.80 m	∞	∞	∞	2.50 m
14 mm	f/8	46.1 cm	4.27 m	∞	∞	∞	∞	1.26 m
28 mm	f/1.8	2.1 cm	8.8 cm	36.0 cm	82.1 cm	2.37 m	11.3 m	22.1 m
28 mm	f/2.8	3.3 cm	13.7 cm	56.6 cm	1.31 m	3.99 m	27.6 m	14.2 m
28 mm	f/4	4.8 cm	19.7 cm	82.5 cm	1.97 m	6.66 m	∞	9.98 m
28 mm	f/8	9.6 cm	40.6 cm	1.88 m	5.57 m	7.3 km	∞	5.00 m
48 mm	f/1.8	0.7 cm	2.9 cm	12.0 cm	27.3 cm	76.6 cm	3.14 m	65.0 m
48 mm	f/2.8	1.1 cm	4.6 cm	18.7 cm	42.6 cm	1.20 m	5.05 m	41.8 m
48 mm	f/4	1.5 cm	6.5 cm	26.8 cm	61.2 cm	1.74 m	7.70 m	29.3 m
48 mm	f/8	3.1 cm	13.1 cm	54.4 cm	1.26 m	3.83 m	25.4 m	14.7 m
78 mm	f/1.8	0.2 cm	1.1 cm	4.5 cm	10.2 cm	28.7 cm	1.16 m	172 m
78 mm	f/2.8	0.4 cm	1.7 cm	7.0 cm	15.9 cm	44.7 cm	1.81 m	110 m
78 mm	f/4	0.5 cm	2.4 cm	10.0 cm	22.7 cm	64.0 cm	2.61 m	77.3 m
78 mm	f/8	1.1 cm	4.8 cm	20.0 cm	45.7 cm	1.30 m	5.50 m	38.7 m

Equivalent aperture#

Exposure is identical at the same f-number on any format; equivalence only describes depth of field and total light.

Aperture on this camera	Full-frame equivalent (depth of field)	Hyperfocal at 28 mm
f/1.2	f/1.8	33.2 m
f/1.4	f/2.1	28.5 m
f/1.8	f/2.7	22.1 m
f/2	f/3.0	19.9 m
f/2.8	f/4.3	14.2 m
f/4	f/6.1	9.98 m
f/5.6	f/8.5	7.14 m
f/8	f/12.2	5.00 m

Diffraction & pixel pitch#

With 4.81 µm pixels, diffraction starts to soften pixel-level detail around f/7.2. For maximum sharpness keep landscapes between f/3.9 and f/7; stopping down further trades detail for depth of field.

Aperture	Airy disk diameter	Spread over	At 100% view
f/2.8	3.8 µm	0.8 px	sharp
f/4	5.4 µm	1.1 px	sharp
f/5.6	7.5 µm	1.6 px	sharp
f/8	10.7 µm	2.2 px	slight softening
f/11	14.8 µm	3.1 px	visibly soft
f/16	21.5 µm	4.5 px	visibly soft
f/22	29.5 µm	6.1 px	visibly soft

Maximum print sizes#

At 16.2 MP the Sony Alpha 55 produces 4,884 × 3,317 pixel images. See the 16 megapixel guide or the print size calculator.

Resolution	Typical use	Inches	Centimetres
300 DPI	Photo-lab quality	16.3 × 11.1 in	41 × 28 cm
240 DPI	Fine-art inkjet	20.4 × 13.8 in	52 × 35 cm
200 DPI	Wall print	24.4 × 16.6 in	62 × 42 cm
150 DPI	Poster, viewed from 1 m+	32.6 × 22.1 in	83 × 56 cm

Night-sky exposure limits#

Longest exposure before stars trail. The NPF rule accounts for pixel pitch and is stricter than the classic 500 rule — use it for pin-sharp stars on high-resolution sensors.

Focal length	500 rule	NPF f/1.8	NPF f/2.8	NPF f/4
9 mm (14 mm eq.)	36.5 s	23.0 s	26.9 s	31.6 s
13 mm (20 mm eq.)	25.3 s	15.9 s	18.6 s	21.9 s
16 mm (24 mm eq.)	20.5 s	13.0 s	15.1 s	17.8 s
23 mm (35 mm eq.)	14.3 s	9.0 s	10.5 s	12.4 s
33 mm (50 mm eq.)	9.9 s	6.3 s	7.3 s	8.6 s

Open the NPF / 500 rule calculator →

Handheld shutter speed guide#

The reciprocal rule uses the equivalent focal length. High-resolution sensors may need one stop faster than this for pixel-sharp results.

Focal length	No stabilisation (1/equiv. focal)	With 3-stop IS	With 5-stop IBIS
16 mm	1/25 s	0.3 s	1.3 s
33 mm	1/50 s	1/6 s	0.6 s
66 mm	1/100 s	1/13 s	0.3 s
131 mm	1/200 s	1/25 s	1/6 s

Lenses for the Sony Alpha 55#

Native Sony / Minolta A-mount lenses in our database (129 total). Also adaptable: T-mount (T2), M42 screw mount, Deckel (DKL), Tamron Adaptall, M39 / LTM (Leica thread).

Samyang 8mm f/3.5 Fish-Eye CS 8 mm
Samyang 10mm f/2.8 ED AS NCS CS 10 mm
Laowa 12mm f/2.8 Zero-D 12 mm
Samyang 14mm f/2.8 AE ED AS IF UMC 14 mm
Laowa 15mm F/4 Wide Angle Macro 15 mm
Samyang 16mm f/2.0 ED AS UMC CS 16 mm
Samyang 20mm f/1.8 ED AS UMC 20 mm
Samyang 24mm f/1.4 ED AS IF UMC 24 mm
Samyang T-S 24mm f/3.5 ED AS UMC 24 mm
Laowa 60mm f/2.8 2X Ultra-Macro 60 mm
Samyang 85mm f/1.4 IF UMC Aspherical 85 mm
Samyang 135mm f/2 ED UMC 135 mm
Sigma 4.5mm f/2.8 EX DC HSM circular fisheye 4.5 mm
Sigma 8-16mm f/4.5-5.6 DC HSM 8–16 mm
Sigma 10-20mm f/3.5 EX DC HSM 10–20 mm
Sigma 10-20mm f/4-5.6 EX DC 10–20 mm
Sigma 10mm f/2.8 EX DC Fisheye HSM 10 mm
Tamron SP AF 10-24mm f/3.5-4.5 Di II LD Aspherical (IF) 10–24 mm
Tamron SP AF 11-18mm f/4.5-5.6 Di-II LD Aspherical (IF) 11–18 mm
Tokina AF 11-16mm f/2.8 AT-X Pro DX 11–16 mm
Tokina AT-X 116 PRO DX II (11-16mm f/2.8) 11–16 mm
Sigma 12-24mm F4.5-5.6 II DG HSM 12–24 mm
Sigma 14mm f/2.8 EX 14 mm
Sigma 14mm f/2.8 EX Aspherical HSM 14 mm
Sigma 14mm f/3.5 EX 14 mm
Sigma 15-30mm f/3.5-4.5 EX DG Aspherical 15–30 mm
Sigma 15mm f/2.8 EX DG Diagonal Fisheye 15 mm
Tamron SP 15-30mm f/2.8 Di VC USD 15–30 mm
Sony AF DT 16-105mm f/3.5-5.6 16–105 mm
Sony DT 16-50mm f/2.8 SSM 16–50 mm
Sony Zeiss Vario-Sonnar T* 16-35mm f/2.8 ZA SSM II 16–35 mm
Tamron 16-300mm f/3.5-6.3 Di II VC PZD Macro B016 16–300 mm
Sigma 17-35mm F2.8-4 EX DG Aspherical HSM 17–35 mm
Sigma 17-35mm f/2.8-4 EX DG 17–35 mm
Sigma 17-50mm f/2.8 EX DC OS HSM 17–50 mm
Sigma 17-70mm f/2.8-4 DC Macro OS HSM | Contemporary 013 17–70 mm

Similar cameras#

Other APS-C cameras from around the same time.

Frequently asked questions#

What is the crop factor of the Sony Alpha 55?

The Sony Alpha 55 has a crop factor of 1.52× relative to 35 mm full frame (diagonal 28.4 mm vs 43.3 mm).

What size is the Sony Alpha 55 sensor?

23.5 × 16.0 mm (APS-C), an area of 375 mm² — 43% of full frame.

Is the Sony Alpha 55 full frame?

No — its sensor is APS-C, which is 2.3× smaller in area than full frame.

How many megapixels does the Sony Alpha 55 have?

16.2 megapixels (4,884 × 3,317 pixels), enough for a 16 × 11 inch print at 300 DPI.

What lens mount does the Sony Alpha 55 use?

The Sony Alpha 55 uses the Sony / Minolta A-mount (flange distance 44.50 mm).

How long can I expose the night sky with the Sony Alpha 55?

With a 13 mm lens (20 mm equivalent) the 500 rule gives 25 s and the stricter NPF rule at f/2.8 gives 19 s.

Sources & licences#

Last updated October 03, 2026 · How we calculate · Sources