Which camera offers the best image quality?
Image quality is evidently of utmost importance for photographic capture. While many aspects of what constitutes a 'good' image are difficult to describe and pin down, some technical foundations for high-quality imaging can be measured. In particular, data scientists at DXO Mark have published camera sensor assessments for well over a decade now that cover important image quality criteria, notably color depth, dynamic range, and low-light sensibility. Similarly, William J. Claff has published extensively about camera sensor performance on his PhotonsToPhotos website.
DXO Mark publishes an overall sensor score, which represents an average of component indicators focusing on characteristics that are important, respectively, for portrait, landscape, and sports photographers. The rating for portrait photography indicates the extent to which a camera sensor can capture color nuances accurately. The landscape score represents the capacity of the sensor to maintain detail in high-contrast settings, and the sports rating shows how well a sensor operates at higher ISO settings without generating excessive amounts of noise in the image.
Considering that imaging is based on the capture of light, it is not surprising that the list of highest rated cameras by image quality is dominated by large-sensor cameras. The Hasselblad X1D currently occupies the top spot with a DXO Total score of 102, followed by the Pentax 645Z. Most of the top-rated cameras also offer relatively high image resolution, suggesting that it is total sensor area and not necessary the size of individual pixels that determines the quality of the capture. The following table shows the 30 highest ranked cameras in descending order of their overall DXO score.
| Camera |
| Launch |
|1.||Hasselblad X1D||102||26.2||14.8||4489||Medium Format||51.3||Jun 2016||8,995|
|2.||Pentax 645Z||101||26.0||14.7||4505||Medium Format||51.1||Apr 2014||8,499|
|3.||Panasonic S1R||100||26.4||14.1||3525||Full Frame||46.7||Feb 2019||3,699|
|4.||Sony A7R III||100||26.0||14.7||3523||Full Frame||42.2||Oct 2017||3,199|
|5.||Fujifilm GFX 50S II||100||25.9||14.8||3456||Medium Format||51.1||Sep 2021||3,999|
|6.||Fujifilm GFX 100S||100||25.8||14.7||3391||Medium Format||101.8||Jan 2021||5,999|
|7.||Nikon Z7 II||100||26.3||14.7||2841||Full Frame||45.4||Oct 2020||2,999|
|8.||Nikon D850||100||26.4||14.8||2660||Full Frame||45.4||Jul 2017||3,299|
|9.||Sony A7R IV||99||26.0||14.8||3344||Full Frame||60.2||Jul 2019||3,499|
|10.||Hasselblad X1D II||99||25.7||14.5||3234||Medium Format||51.3||Jun 2019||5,750|
|11.||Fujifilm GFX 100||99||25.7||14.5||3227||Medium Format||101.8||May 2019||9,999|
|12.||Nikon Z7||99||26.3||14.6||2668||Full Frame||45.4||Aug 2018||3,399|
|13.||Sony A7R II||98||26.0||13.9||3434||Full Frame||42.2||Jun 2015||3,199|
|14.||Fujifilm GFX 50R||98||25.7||14.4||3169||Medium Format||51.1||Sep 2018||4,499|
|15.||Sony A1||98||25.9||14.5||3163||Full Frame||49.8||Jan 2021||6,499|
|16.||Leica S3||98||25.6||14.4||3143||Medium Format||64.0||Sep 2018||18,995|
|17.||Sony RX1R II||97||25.8||13.9||3204||Full Frame||42.2||Oct 2015||3,299|
|18.||Nikon D810||97||25.7||14.8||2853||Full Frame||36.2||Jun 2014||3,299|
|19.||Sony A7 III||96||25.0||14.7||3730||Full Frame||24.0||Feb 2018||1,999|
|20.||Pentax K-1||96||25.4||14.6||3280||Full Frame||36.2||Feb 2016||1,799|
|21.||Sony A7 IV||96||25.4||14.5||3052||Full Frame||32.7||Oct 2021||2,499|
|22.||Canon R3||96||25.4||14.5||3048||Full Frame||24.0||Sep 2021||5,999|
|23.||Sigma fp L||96||25.3||14.4||3001||Full Frame||60.2||Mar 2021||2,499|
|24.||Nikon D800E||96||25.6||14.3||2979||Full Frame||36.2||Feb 2012||3,299|
|25.||Fujifilm GFX 50S||96||25.4||14.1||2977||Medium Format||51.1||Sep 2016||6,499|
|26.||Leica Q2||96||26.4||13.5||2491||Full Frame||46.7||Mar 2019||4,995|
|27.||Leica SL2-S||95||25.2||14.1||3504||Full Frame||24.0||Dec 2020||4,895|
|28.||Sony A7C||95||25.0||14.7||3407||Full Frame||24.0||Sep 2020||1,799|
|29.||Panasonic S1||95||25.2||14.5||3333||Full Frame||24.0||Feb 2019||2,499|
|30.||Nikon Z6||95||25.3||14.3||3299||Full Frame||24.3||Aug 2018||1,999|
|Note: DXO values in italics represent estimates based on sensor size and age.|
The overall ranking above comprises very different camera types. Here are some rankings by category:
- Best Medium Format Cameras
- Best Full-Frame Cameras
- Best APS-C Cameras
- Best DSLR Cameras
- Best Mirrorless (MILC) Cameras
- Best Superzoom Compact Cameras
- Best Travel Zoom Compact Cameras
- Best Prime Lens Compact Cameras
Estimating missing DXO Mark scores
DXO Mark provides sensor quality scores for many, but not for all cameras. Perhaps this less than complete coverage is understandable given the considerable time and effort that goes into the measurement of camera sensor characteristics. Yet, missing values are a nuissance for photographers who want to assess and compare a camera that has not or not yet been reviewed by the experts at DXO Mark. In this context, regression-based estimates can provide a useful indication on the likely performance of the sensor in a non-reviewed camera.
The two most important determinants of image sensor quality are sensor size and sensor age. A larger sensor generally scores higher on all the image quality characteristics assessed by DXO Mark. When compared with smaller sensors of the same technological era, the large chip provides more color depth, higher dynamic range, and better low-light sensitivity, which results in a higher total image quality score (see graph below).
The second critical determinant for imaging quality is the release date of the sensor. Technological progress has made it possible to enhance the capacity of sensors to capture high quality images over time even as the resolution of cameras has risen markedly. Newer cameras, thus, tend to outperform older models of the same sensor class. In some cases, the technological advances can even more than compensate for differences in sensor size. For example, the Olympus OMD E-M1 II of 2016 has higher DXO Mark scores for portrait, landscape, and sports use than the Leica M9 of 2009, even though the latter has a full-frame sensor that is four times as large as the Four Thirds chip in the OMD.
Regression analysis can then be used to predict missing DXO Mark values based on the size and age of the imaging sensor. The resulting estimates can give an indication where the sensor quality measures will likely fall if an actual measurement of the quality characteristics were to be undertaken. This information might be useful when comparing different cameras.
Beyond image quality
The imaging quality of the sensor is, of course, an important aspect of any camera decision but certainly not the only one. Camera handling, speed, features, and connectivity are among the other criteria that need to be considered. The CAM-parator App can be used to compare any two cameras and assess their relative strengths across several feature dimensions. Just enter two comparators into the search boxes below and you will promptly be taken to a respective comparison.