Sony RX10 Mark IV Bridge Camera
Review, Test, Hands-on Report2019 © Thomas Gade
Sony RX10 IV with its tilting display mounted on a tripod
Bridge Camera with a 1" Sensor
For many years Sony has relied on the relatively large 1" sensor when designing high-quality bridge cameras in order to achieve excellent image quality with only minimal compromises. But does the bridge camera concept still fit into today's digital camera landscape? What is it particularly well suited for?These questions are answered in this detailed hands-on review of the Sony RX10 IV. To summarize in advance: the image quality of the small sensor exceeded my expectations and the optical performance of the zoom lens is outstanding.
The Sony RX10 IV was used at Berlin Zoo, in a village in Brandenburg with numerous storksand for photographing waterfowl at Lake Tegel. To evaluate its close-up capabilities, flowers in a balcony planter served as test subjects, while a sightseeing tour through Berlin provided a variety of tourist scenes.
Technical Specifications
| Manufacturer | Sony |
| Model | Sony RX10 Mark IV |
| Introduced | 2017 |
| Type | Bridge Camera |
| Format | 1" Sensor * ( 13.2 x 8.8 mm) |
| Shutter Speed | Mechanical up to 1/2000 s and electronic up to 1/32000 s |
| Resolution | 20 MP |
| Weight | 1120 g |
| Dimensions | |
| Price | 1650 (August 2019) |
* The designation 1" sensor (1-inch sensor) is a historical relic from 1950s television technology and does not represent the actual diameter of the sensor. Early television cameras used glass video camera tubes (such as Vidicon tubes). The size specification referred to the outer diameter of the entire glass tube. For a glass tube with an outer diameter of 1 inch (25.4 mm), the usable image diagonal inside was only about 16 millimeters.
Wide Focal Length Range
The Sony RX10 IV features a Zeiss Vario-Sonnar T* lens with a variable focal length of 8.8–220 mm and a maximum aperture ranging from f/2.4 to f/4. In full-frame equivalent terms, this corresponds to a fast zoom lens covering 24–600 mm.
Zoom range of the Sony RX10 Mark IV from the widest setting of 8.8 mm (24 mm full-frame equivalent) to the maximum focal length of 220 mm (600 mm full-frame equivalent)
Fast Super-Telephoto Lens
An aperture of f/4 at 600 mm (full-frame equivalent) corresponds to a fast super-telephoto lens. For a full-frame camera, you would need a lens such as the Canon EF 600mm f/4 IS USM to achieve the same specifications. Like the Zeiss lens in the Sony camera, Canon's 600 mm telephoto lens incorporates optical image stabilizationand both lenses focus quickly and quietly. According to the manufacturers, the minimum focusing distance is 4.5 m for the Canon lens and 1.96 m for the Sony. The Canon 600 mm lens alone weighs almost 4 kg, whereas the complete Sony RX10 IV, including battery and memory card, weighs only 1.12 kg.
Sony RX10 IV. Two views with the zoom lens retracted and extended. (Image created from two Sony press photos.)
No Weaknesses at Long Focal Lengths
A wide zoom range is only enjoyable if high image quality is maintained throughout the entire focal length range. Many zoom lenses become noticeably weaker at the longest telephoto setting. If acceptable sharpness is achieved at all, it often requires stopping down to f/8 or even f/11, resulting in longer exposure times or higher ISO settings.Does this also apply to the Sony RX10 IV lens? No. Even at the maximum focal length, the Zeiss Vario-Sonnar delivers excellent sharpness wide open. Depth of field is naturally very shallow, placing high demands on the autofocus system, but when everything works together, the results are impressive. The optical image stabilizer is so effective that many sharp handheld images can be taken at long focal lengths, provided the autofocus locks on accurately.
Today, image quality depends not only on excellent optics. Modern lenses are carefully measured at different apertures and magnifications to identify distortion, vignettingand chromatic aberration, many of which can be corrected by software. Initial tests showed that both the camera's internal image processing and the automatic lens corrections in the RAW converters ACDSee Photo Studio 19 and DxO PhotoLab 2 perform this task extremely well. Color fringing and softness in the image corners are negligible throughout the entire zoom range of the Sony RX10 IV.
The shallow depth of field at long focal lengths requires precise selection of the area that should be in focus.
Top: complete image. Middle: focus on the sign. Bottom: focus on the lifebuoy.
The longer the focal length, the shallower the depth of field becomes. At the maximum telephoto setting of 220 mm (600 mm full-frame equivalent), close-up and medium-distance subjects with elements at different distances require you to decide exactly which part of the image should be in focus. The easiest way is to tap the desired point on the touchscreen. Alternatively, focus stacking can be used to combine several images and achieve greater depth of field.
Digital Zoom by Cropping
If the 220 mm (600 mm full-frame equivalent) focal length is not sufficient, image files captured at ISO settings below 1000 still provide enough quality for high-quality cropped enlargements.
Pool frog on a water lily leaf in a pond at the NABU Stork Sanctuary in Linum. Settings: f/8, ISO 200, 1/250 s, 220 mm (600 mm full-frame equivalent)
Crop from the image
Larger crop from the image (100% / 800 × 533 pixels)
Barn swallow. Crop from an image. Settings: f/4, ISO 160, 1/250 s, 220 mm (600 mm full-frame equivalent)