Sony DSLR-A580 Review

 
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Sony A580 Imatest Dynamic Range Analysis

We routinely use Norman Koren's excellent "Imatest" analysis program for quantitative, thoroughly objective analysis of digicam test images. I highly recommend it to our technically-oriented readers, as it's far and away the best, most comprehensive analysis program I've found to date.

My comments below are just brief observations of what we see in the Imatest Dynamic Range results. A full discussion of all the data Imatest produces is really beyond the scope of this review: Visit the Imatest web site for a full discussion of what the program measures, how it performs its computations, and how to interpret its output.

A key parameter in a digital camera is its Dynamic Range, the range of brightness that can be faithfully recorded. At the upper end of the tonal scale, dynamic range is dictated by the point at which the RGB data "saturates" at values of 255, 255, 255. At the lower end of the tonal scale, dynamic range is determined by the point at which there ceases to be any useful difference between adjacent tonal steps. Note the use of the qualifier "useful" in there: While it's tempting to evaluate dynamic range as the maximum number of tonal steps that can be discerned at all, that measure of dynamic range has very little relevance to real-world photography. What we care about as photographers is how much detail we can pull out of the shadows before image noise becomes too objectionable. This, of course, is a very subjective matter, and will vary with the application and even the subject matter in question. (Noise will be much more visible in subjects with large areas of flat tints and subtle shading than it would in subjects with strong, highly contrasting surface texture.)

What makes most sense then, is to specify useful dynamic range in terms of the point at which image noise reaches some agreed-upon threshold. To this end, Imatest computes a number of different dynamic range measurements, based on a variety of image noise thresholds. The noise thresholds are specified in terms of f-stops of equivalent luminance variation in the final image file, and dynamic range is computed for noise thresholds of 1.0 (low image quality), 0.5 (medium image quality), 0.25 (medium-high image quality) and 0.1 (high image quality). For most photographers and most applications, the noise thresholds of 0.5 and 0.25 f-stops are probably the most relevant to the production of acceptable-quality finished images, but many noise-sensitive shooters will insist on the 0.1 f-stop limit for their most critical work.

The image below shows the test results from Imatest for an in-camera JPEG file from the Sony A580 with a nominally-exposed density step target (Stouffer 4110), at default contrast and with its DRO and HDR settings turned off.

We got the best dynamic range scores from the Sony A580 at ISO 100. Here, we can see that the tone curve maintains excellent gradation in the highlights while the shadow end also trails-off quite nicely.  Total dynamic range was 10.6 f-stops, and at the highest quality level, dynamic range was 8.51 f-stops, the best High Quality Imatest score for an in-camera JPEG we have tested to date.

Processing the Sony A580's RAW (.ARW) files through Adobe Camera Raw (ACR) version 6.4 increased dynamic range by about 1.25 f-stops at the highest quality level (9.76 f-stops), compared to the in-camera JPEG (8.51 f-stops) while total dynamic range reported increased from 10.6 to 12.2 f-stops. These results were obtained by using ACR's automatic settings; slightly better results may be possible by manually tweaking from there, but we weren't able to improve on them. It's worth noting here that ACR's default noise reduction settings reduced overall noise (see the plot in the lower left-hand corner) relative to the levels in the in-camera JPEG, which would tend to boost the dynamic range numbers for the High Quality threshold. Also, the extreme highlight recovery being performed by ACR here would likely produce color errors in strong highlights of natural subjects.

Dynamic Range, the bottom line:

The net result was that the Sony A580's JPEGs showed excellent dynamic range scores, some of the best we've tested to date. RAW dynamic range performance with Adobe Camera RAW was also outstanding, producing a score that put it within the top three cameras. That's no surprise, since the top three happen to use the same or very similar 16-megapixel sensor.

To get some perspective, here's a summary of the Sony A580's dynamic range performance, and how it compares to other digital SLRs that we also have Imatest dynamic range data for. (Results are arranged in order of decreasing dynamic range at the "High" quality level.):

Dynamic Range (in f-stops) vs Image Quality
(At camera's base ISO)

(Blue = RAW via ACR, Yellow=Camera JPEG, Green=Current Camera)
Model 1.0
(Low)
0.5
(Medium)
0.25
(Med-High)
0.1
(High)
Pentax K-5
(Adobe Camera Raw 6.3)
11.5 11.5 11.2 10.2
Nikon D7000
(Adobe Camera Raw 6.3)
12.0 11.9 11.6 10.1
10.0 Stops
Sony A580
(Adobe Camera Raw 6.4)
12.2 12.2 11.1 9.76
Nikon D3X
(Adobe Camera Raw 5.3b)
-- -- 11.1 9.64
Nikon D3S
(Adobe Camera Raw 5.6)
-- -- 10.7 9.55
Nikon D700
(Adobe Camera Raw 4.5)
12.1 11.6 10.6 9.51
Nikon D5000
(Adobe Camera Raw 5.4b)
-- 11.6 10.8 9.50
9.5 Stops
Sony A33
(Adobe Camera Raw 6.2)
-- -- 10.7 9.37
Sony A900
(Adobe Camera Raw 4.6b)
-- 12.1 10.7 9.36
Pentax K-x
(Adobe Camera Raw 5.6b)
11.5 11.2 10.7 9.33
Nikon D90
(Adobe Camera Raw 4.6b)
12.1 11.8 10.7 9.27
Sony A55
(Adobe Camera Raw 6.2)
11.1 10.9 10.5 9.16
Fujifilm S3 Pro
(Adobe Camera Raw 2)
12.1 11.7 10.7 9.00
9.0 Stops
Sony NEX-5
(Adobe Camera Raw 6.2b)
11.9 11.5 10.4 8.95
Sony A230
(Adobe Camera Raw 5.5)
11.7 11.1 10.1 8.95
Nikon D40x
(Adobe Camera Raw 4.1)
12.0 10.9 10.3 8.90
Canon 1D Mark IV
(Adobe Camera Raw 5.7)
-- 11.0 10.1 8.90
Nikon D300S
(Adobe Camera Raw 5.5)
-- 11.3 10.4 8.89
Canon 5D Mark II
(Adobe Camera Raw 5.2)
-- 10.8 10.0 8.89
Sony NEX-3
(Adobe Camera Raw 6.2b)
11.8 11.4 10.1 8.87
Sony A330
(Adobe Camera Raw 5.4)
-- -- 10.1 8.86
Canon EOS-1Ds Mark III
(Adobe Camera Raw 4.5)
11.5 10.7 9.96 8.84
Nikon D3
(Adobe Camera Raw 4.5)
11.7 11.0 10.0 8.75
Canon EOS-1D Mark III
(Adobe Camera Raw 4.5)
11.7 10.7 9.99 8.73
Sony A380
(Adobe Camera Raw 5.5)
11.8 10.9 10.1 8.62
Nikon D3000
(Adobe Camera Raw 5.5)
-- 10.8 10.1 8.61
Sony A560
(Adobe Camera Raw 6.3)
11.8 11.0 10.1 8.59
Pentax K20D
(Adobe Camera Raw 4.5)
11.4 10.6 9.82 8.56
Sony A580
(Camera JPEG)
10.7 9.77 9.20 8.51
8.5 Stops
Nikon D300
(Adobe Camera Raw 4.3.1)
11.4 10.9 9.87 8.45
Sony A200
(Adobe Camera Raw 4.3.1)
11.6 10.4 9.82 8.43
Nikon D60
(Adobe Camera Raw 4.4.1)
11.6 10.5 9.74 8.31
Nikon D40
(Adobe Camera Raw 4.1)
11.9 10.9 9.89 8.30
Nikon D3100
(Adobe Camera Raw 6.3b)
10.9 10.2 9.28 8.24
Canon EOS-1Ds Mark III
(Camera JPEG)
10.9 10.2 9.71 8.23
Pentax K100D
(Adobe Camera Raw 3.6)
11.3 10.3 9.51 8.23
Pentax K200D
(Adobe Camera Raw 4.4.1)
-- 10.5 9.54 8.19
Pentax K10D
(Adobe Camera Raw 3.7)
10.6 10.0 9.29 8.19
Canon 7D
(Adobe Camera Raw 5.6)
11.2 10.3 9.52 8.18
Sony A100
(Adobe Camera Raw 3.4)
11.3 10.5 9.69 8.16
Canon EOS-1Ds Mark II
(Adobe Camera Raw 3)
11.2 10.3 9.40 8.14
Canon 1D Mark IV
(Camera JPEG, ISO 50)
-- -- 8.45 8.10
Canon EOS 50D
(Adobe Camera Raw 4.6)
11.2 10.5 9.49 8.06
Nikon D40x
(Camera JPEG)
10.8 10.0 9.42 8.04
Olympus E-P1
(ISO 200,
Adobe Camera Raw 5.5)
11.5 10.4 9.26 8.04
Canon Rebel XSi
(Camera JPEG)
(ALO on by default)
11.3 10.1 9.34 8.01
8.0 Stops
Nikon D7000
(Camera JPEG)
9.97 9.81 9.73 7.97
Nikon D3S
(Camera JPEG)
-- -- -- 7.96
Fujifilm S3 Pro
(Camera JPEG)
-- 9.90 9.40 7.94
Canon T2i
(Adobe Camera Raw 5.7)
-- 10.0 9.21 7.94
Samsung NX10
(Adobe Camera Raw 5.7 beta)
-- -- 9.18 7.91
Sony A350
(Adobe Camera Raw 4.4)
11.6 10.5 9.61 7.89
Canon EOS-1D Mark III
(Camera JPEG)
-- 10.2 9.70 7.88
Olympus E-P2
(Adobe Camera Raw 5.6)
-- 10.2 9.44 7.88
Canon Rebel XS
(Adobe Camera Raw 4.5)
-- 10.3 9.27 7.88
Nikon D3
(Camera JPEG)
-- -- -- 7.87
Canon Digital Rebel XTi
(Adobe Camera Raw 3.6)
10.8 9.88 9.18 7.84
Canon EOS 5D
(Adobe Camera Raw 3)
11.0 10.4 9.21 7.83
Nikon D90
(Camera JPEG)
-- -- -- 7.77
Panasonic DMC-GH1
(Adobe Camera Raw 5.4b)
9.88 -- 9.30 7.76
Canon 60D
(Adobe Camera Raw 6.3)
10.7 9.88 9.12 7.75
Sony A55
(Camera JPEG)
9.59 9.36 8.70 7.74
Canon Rebel T1i
(Adobe Camera Raw 5.4b)
11.2 10.2 9.16 7.73
Pentax K-7
(Adobe Camera Raw 5.4)
10.6 9.93 9.07 7.73
Canon EOS 40D
(Adobe Camera Raw 4.2)
11.2 10.1 9.26 7.72
Panasonic DMC-GH1
(Camera JPEG)
8.77 -- -- 7.70
Canon Rebel XSi
(Adobe Camera Raw 4.4.1)
10.6 9.95 9.10 7.68
Canon EOS 50D
(Camera JPEG)
(ALO STD by default)
-- -- 8.90 7.68
Sony A33
(Camera JPEG)
-- 9.95 9.17 7.67
Nikon D700
(Camera JPEG)
-- -- 9.05 7.67
Canon 5D Mark II
(Camera JPEG)
(ALO STD by default)
10.6 9.68 8.98 7.66
Nikon D5000
(Camera JPEG)
-- -- 8.96 7.65
Sony A560
(Camera JPEG)
10.5 10.2 8.86 7.65
Canon EOS-5D
(Camera JPEG)
10.2 9.68 8.82 7.65
Olympus E-3
(Adobe Camera Raw 4.3)
10.3 10.1 9.29 7.64
Nikon D3100
(Camera JPEG)
10.2 9.92 9.27 7.62
Nikon D60
(Camera JPEG)
10.5 9.62 8.89 7.62
Nikon D200
(Adobe Camera Raw 3)
10.6 9.65 8.96 7.61
Sony NEX-5
(Camera JPEG)
10.4 9.64 8.82 7.57
Canon 7D
(Camera JPEG)
(ALO STD by default)
-- 9.70 8.54 7.54
Canon T2i
(Camera JPEG)
-- 9.44 8.45 7.53
Nikon D80
(Adobe Camera Raw 3.6)
11.1 10.4 9.42 7.51
7.5 Stops
Nikon D300S
(Camera JPEG)
-- -- -- 7.49
Olympus E-500
(Adobe Camera Raw 3)
10.7 9.97 8.90 7.46
Canon 60D
(Camera JPEG)
(ALO=STD by default)
10.2 9.74 8.74 7.46
Olympus E-510
(Adobe Camera Raw 4.1)
10.0 9.43 8.64 7.46
Pentax K10D
(Camera JPEG)
-- 9.49 8.88 7.44
Sony NEX-3
(Camera JPEG)
10.0 9.62 8.86 7.44
Nikon D300
(Camera JPEG)
-- -- 8.70 7.44
Olympus E-420
(Adobe Camera Raw 4.1.1)
10.0 9.61 8.65 7.44
Canon Rebel T1i
(Camera JPEG)
(ALO=STD by default)
11.3 10.1 9.34 7.43
Nikon D2Xs
(Adobe Camera Raw 3.6)
10.6 9.90 8.93 7.42
Canon EOS 40D
(Camera JPEG)
10.6 9.52 8.78 7.42
Olympus E-PL1
(Adobe Camera Raw 5.7)
10.4 9.89 8.76 7.39
Nikon D3X
(Camera JPEG)
-- -- -- 7.37
Nikon D50
(Camera JPEG)
10.7 9.93 8.70 7.36
Panasonic DMC-G2
(Adobe Camera Raw 5.7)
10.3 9.87 8.77 7.35
Sony A380
(Camera JPEG)
(DRO Standard by default)
-- 9.54 8.84 7.32
Panasonic DMC-G1
(Adobe Camera Raw 5.2)
10.7 9.78 8.70 7.32
Nikon D3000
(Camera JPEG)
10.2 9.64 8.69 7.31
Sony A900
(Camera JPEG)
(DRO off by default )
10.2 9.75 8.49 7.31
Sony A330
(Camera JPEG)
(DRO Standard by default)
10.1 9.37 8.59 7.30
Sony A200
(Camera JPEG)
(DRO on by default)
10.4 9.43 8.91 7.29
Canon EOS 20D
(Camera JPEG)
10.3 9.66 8.85 7.29
Canon EOS 30D
(Camera JPEG)
10.3 9.50 8.57 7.29
Nikon D40
(Camera JPEG)
10.4 9.80 8.89 7.28
Sony A230
(Camera JPEG)
(DRO Standard by default)
10.1 9.51 8.51 7.26
Sony A900
(Camera JPEG)
(DRO on)
10.1 9.76 8.47 7.26
Pentax K-5
(Camera JPEG)
10.2 9.43 8.64 7.22
Canon Rebel XS
(Camera JPEG)
10.3 9.40 8.61 7.22
Olympus E-520
(Adobe Camera Raw 4.5)
11.0 9.46 8.70 7.20
Sony A350
(Camera JPEG)
(DRO on by default)
10.3 9.55 8.85 7.19
Pentax K-x
Camera JPEG
9.99 8.94 8.31 7.18
Panasonic DMC-GF1
(Adobe Camera Raw 5.5)
10.2 9.62 8.62 7.16
Nikon D80
(Camera JPEG)
10.1 9.43 8.48 7.12
Canon Digital Rebel XT
(Camera JPEG)
10.3 9.51 8.61 7.11
Nikon D200
(Camera JPEG)
-- 9.07 8.36 7.11
Olympus E-300
(Camera JPEG)
10.8 9.26 8.48 7.07
Olympus E-410
(Adobe Camera Raw 4.1)
10.2 9.40 8.24 7.05
Olympus E-500
(Camera JPEG)
10.0 9.14 8.16 7.05
Canon Digital Rebel XTi
(Camera JPEG)
9.83 9.10 8.27 7.04
Canon EOS-1Ds Mark II
(Camera JPEG)
10.3 9.38 8.60 7.04
Panasonic DMC-G1
(Camera JPEG)
-- 9.33 8.52 7.03
Pentax K200D
(Camera JPEG)
-- 9.50 8.30 7.01
7.0 Stops
Panasonic DMC-GF1
(Camera JPEG)
-- 9.33 8.44 6.99
Canon Digital Rebel
(Camera JPEG)
10.1 9.11 8.47 6.97
Nikon D2Xs
(Camera JPEG)
9.82 8.98 8.23 6.97
Panasonic DMC-L10
(Adobe Camera Raw 4.2)
10.4 9.34 8.48 6.91
Sigma DP1
(Camera JPEG)
-- 8.95 8.13 6.91
Pentax *istDs
(Camera JPEG)
10.2 10.0 8.87 6.90
Sony A100
(Camera JPEG)
10.2 9.24 8.39 6.89
Samsung NX10
(Camera JPEG,
Smart Range, ISO 200)
10.1 8.99 8.22 6.78
Pentax K100D
(Camera JPEG)
10.3 9.30 8.39 6.73
Panasonic DMC-G2
(Camera JPEG)
9.72 9.18 8.15 6.68
Pentax K20D
(Camera JPEG)
10.2 9.21 8.09 6.66
Pentax K-7
(Camera JPEG)
9.59 8.87 8.03 6.54
6.5 Stops
Nikon D2x
(Camera JPEG)
-- 8.93 7.75 6.43
Olympus E-3
(Camera JPEG)
9.32 9.06 8.50 6.42
Panasonic DMC-L10
(Camera JPEG)
-- 8.94 8.00 6.38
Olympus E-420
(Camera JPEG)
9.18 8.82 7.93 6.37
6.0 Stops
Olympus E-410
(Camera JPEG)
-- -- 7.60 5.99
Olympus E-PL1
(Camera JPEG,
Gradation = Normal)
-- 8.63 7.45 5.89
Samsung NX10
(Camera JPEG)
9.32 8.48 7.46 5.88
Nikon D70s
(Camera JPEG)
9.84 8.69 7.46 5.85
Nikon D70
(Camera JPEG)
9.81 8.76 7.58 5.84
Olympus E-520
(Camera JPEG)
9.32 8.68 7.74 5.74
Olympus E-P2
(Camera JPEG,
Gradation = Normal)
10.1 8.83 7.78 5.58
Olympus E-P1
(Camera JPEG,
Gradation = Normal)
-- 8.85 7.74 5.47

Note that this test is repeatable to within 1/3 EV according to the Imatest website, so differences of less than 0.33 can be ignored.

 

Sony DSLR-A580

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