More on usable dynamic range

After my previous post, I got a couple of questions on usable (or useful) dynamic range. To start with, the DxOlabs‘ version of dynamic range, the total range, is utterly useless. It measures the range up to where the signal/noise ratio is 1, i.e. the noise is as strong as the signal or image. That’s NOT a pretty image, it’s horrible. You’ve lost it long before that. That’s why I find the imaging-resource.com testing much more interesting. They test the dynamic range with different signal/noise ratios, i.e. how much less must the noise be than the signal/image for you to have an acceptable image. It seems that around 5-6 times stronger image signal than noise yields a nice image. Lower than that, you would not like to go.

In the imaging-resource.com tests (up until lately), they provide measurements for four signal/noise ratios: 1, 2, 4, and 10. Since we would rather have the dynamic range evaluated at about a rate of 5-6, I use the average of the measurements for the ratios 4 and 10. Since ((1/4 + 1/10) / 2) is around 1/5.7, that will give us the most reasonable figure on usable dynamic range. I have compiled that figure from many of the tests on imaging-resource.com and rounded the results to the nearest 0.2 f-stops (reasonable measurement error margin), so the table is courtesy of them. The measurements are all at native (base) ISO, which ranges from 80 to 200 on the cameras tested. The table shows the figures from RAW image files converted using Adobe Camera Raw (the version available at the test of each camera).

Nikon D5200 11.4
Nikon Coolpix A 11.4
Nikon D600 11.2
Ricoh GR 11.0
Nikon D4 10.8
Nikon D7100 10.8
Nikon D7000 10.8
Nikon D5100 10.8
Pentax K-5 10.8
Nikon D800 10.6
Sony A99 10.4
Nikon D3X 10.4
Nikon D5000 10.2
Nikon D3S 10.2
Nikon D700 10.0
Sony A33 10.0
Sony A900 10.0
Pentax K-x 10.0
Nikon D90 10.0
Fujifilm S3 Pro 9.8
Sony A55 9.8
Sony NEX-5 9.6
Nikon D300S 9.6
Nikon D40x 9.6
Sony A230 9.6
Canon 1D Mark IV 9.6
Sony NEX-3 9.4
Sony A330 9.4
Canon 5D Mark II 9.4
Canon EOS-1Ds Mark III 9,4
Nikon D3 9.4
Canon EOS-1D Mark III 9,4
Sony A380 9.4
Nikon D3000 9.4
Pentax K20D 9.2
Nikon D300 9.2
Sony A200 9.2
Nikon D40 9.0
Nikon D60 9.0
Sony A100 9.0
Pentax K100D 8.8
Pentax K200D 8.8
Canon 7D 8.8
Canon EOS 50D 8.8
Canon EOS-1Ds Mark II 8.8
Nikon D3100 8.8
Sony A350 8.8
Pentax K10D 8.8
Olympus E-P2 8.6
Olympus E-P1 8.6
Canon T2i 8.6
Canon Rebel XS 8.6
Canon EOS 5D Mk III 8.6
Samsung NX10 8.6
Panasonic DMC-GH1 8.6
Canon EOS 5D 8.6
Canon Digital Rebel XTi 8.6
Canon EOS 40D 8.4
Olympus E-3 8.4
Nikon D80 8.4
Canon Rebel T1i 8.4
Pentax K-7 8.4
Canon Rebel XSi 8.4
Nikon D200 8.2
Canon 1D Mark IV 8.2
Olympus E-500 8.2
Nikon D2Xs 8.2
Olympus E-PL1 8.0
Panasonic DMC-G2 8.0
Olympus E-510 8.0
Olympus E-420 8.0
Panasonic DMC-G1 8.0
Olympus E-520 8.0
Panasonic DMC-GF1 7.8
Panasonic DMC-L10 7.6
Olympus E-410 7.6

The Nikon D70, the subject of this blog, is not in the table. The closest we come is the D40 which uses the same sensor (the D40, D50 and D70/D70s share the same ICX453 sensor while the older D100 has the ICX413 sensor, both from Sony). At 9.0 f-stops, the usable dynamic range of the D40/D50/D70 is ok but not very good. To gain some considerable range, one need to look at full stop gains. At around 10 f-stops, we find the previous generation of Nikon full-frames as well as the D90/D5000/D300s using the Sony IMX038 sensor (the D300 uses the older IMX021 sensor and is rather close to the D70). To gain one more stop, up to around 11, you need to consider the latest sensors such as D7000/D5100 (Sony IMX071 sensor), D4, or D7100/D5200 (Toshiba 5051 sensor). The D5300 is unfortunately not tested in this way (but has the same Toshiba 5051 sensor as D7100/D5200) and the D800 is lagging behind (that design had other priorities).

Note that the measurements in the table are real-life figures. That includes not only the sensor but read-out electronics and in-camera image processing. Yes, that’s right – processing. There is a lot of in-camera processing even for “raw” data, also at base ISO. Even more at higher ISO, otherwise your images, especially CMOS, would look horrible. Further, the figures are after conversion in Adobe Camera Raw since you as the end-user must make a raw conversion in order to access the images.

As I wrote in a previous post, the most notable fact is that full-frame cameras are not ahead of half-frame (DX or APS-C) ones from the same era. Full-frame has a lot of advantages, such as high-ISO noise being lower, but dynamic range at base ISO is not one of them.

These are RAW file data, figures from JPEG image files show much less dynamic range. Typically around 1.2-1.5 stops difference, which is one good reason why you should shoot in RAW, at least in scenes with a high natural contrast. The absolutely best of the latest DSLRs have the same usable dynamic range in JPEG (around 9 f-stops) as the D70 has in RAW. Another way of saying this is that if you are a D70 JPEG shooter, you would gain the same in real-life dynamic range from either upgrading to one of the latest-and-greatest Nikon DSLRs or simply switching to using RAW on your D70.

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