Sony RX100 IV Field Test

Sony RX100 IV Field Test

Plenty of power in your pocket

by Jeremy Gray | Posted 09/04/2015

New sensor design brings new features

The Sony Cyber-shot DSC-RX100 IV may look identical to the RX100 III, but there are numerous internal changes that lead to much improved capabilities and results, particularly for high speed photography and movie recording. The RX100 IV uses a new 1-inch-type CMOS sensor that features a stacked design, which allows for much higher speed shooting than the previous RX100 III.

Key Features

• 20.1 megapixel backside-illuminated Exmor RS 1-inch-type CMOS sensor with stacked design
• Native ISO range of 125-12,800, expandable to 80-25,600
• Compact camera body
• Pop-up XGA OLED electronic viewfinder
• 24-70mm equivalent f/1.8-2.8 lens
• 16fps continuous shooting
• 1/32000s electronic shutter
• 4K resolution video
• High-speed video recording

Small form factor causes some issues with camera handling

Like the three versions of RX100 before it, the RX100 IV is very small and light. The RX100 IV weighs only 10.5 ounces (298 grams) with a battery. When the camera is off and the lens is retracted, it can even be carried in a pants or jacket pocket. The electronic viewfinder is built-in, but uses a pop-up design, which helps to keep the camera small. A pocket-friendly camera comes with some compromises, however, such as not having much to hold onto and its buttons being small and close together.

With its smooth, matte finish, the camera looks great, however, this finish can be quite slippery. The RX100 IV doesn't have any front grip, which contributes to it being a difficult camera to get a good hold of. There is a Sony AG-R2 accessory grip available for purchase ($15 as of this writing) that looks like it would help improve the situation quite a bit. The included wrist strap, rather than a neck strap, didn't help to alleviate my worry about dropping the camera.

The lens has a control ring that has a diamond-knurled texture. The control ring itself is very narrow, as necessitated by the short length of the lens when retracted, but it means that there isn't a lot to hold onto when using the control ring to make adjustments. Additionally, the control ring rotates so smoothly that it can be difficult to use for making precise adjustments like selecting a shutter speed or aperture.

The 3-inch rear display is sharp and vibrant with 1,228,800 dots and can tilt 180 degrees upward and 45 degrees downward, but cannot swivel to the sides. The display has a sunny weather mode that greatly increases its usability in bright lighting conditions. However, with so many displays being touchscreen these days, especially on compact cameras, it's a surprising and unfortunate omission here on a camera packed with so many features.

The unique new sensor produces excellent images

The RX100 IV uses an all-new sensor that is the world's first stacked sensor. The sensor is a backside-illuminated 1-inch-type CMOS sensor, like previous RX100-series cameras, but this new Exmor RS sensor stacks memory and electronic components behind the light-sensitive surface. Compared to a traditional design, which doesn't stack components and also doesn't have the attached DRAM that the Exmor RS sensor does, the RX100 IV has 5x faster data readout. This improved performance allows for 4K video capture, a high-speed electronic shutter capable of 1/32000s shutter speeds, high-speed video recording, and a large reduction in the level of rolling shutter.

In my shooting, the RX100 IV produces excellent images, particularly at low ISO settings. Image files have accurate colors and excellent depth. I found that RAW files need a bit of sharpening, but JPEG files are sharp straight from the camera. RAW files provide a lot of flexibility for post-processing, including the ability to recover highlights and push shadow area detail very well. Both RAW and JPEG files exhibit an impressive dynamic range, which seems to be standard for Sony cameras these days.

24-70mm f/1.8-2.8 lens impresses throughout its range

The RX100 IV's 24-70mm equivalent f/1.8-2.8 lens is excellent. The lens has a 10-element, 9-group design with 9 aspheric elements and includes a Zeiss T* coating. While a 2.9x optical zoom isn't a lot, and might not work well for everyone and the kinds of photography they do, the optical performance of the lens is impressive across its entire range. The lens is sharpest in the middle portion of its focal length range, from around 35-50mm, but it remains sharp at the extreme focal lengths as well. Distortion is well-controlled and aberrations are minimal and there are not any extreme cases of fringing. With that said, there is minor purple fringing around high-contrast fine details. I found that there is a decrease in sharpness around the edges of the frame when shooting wide open, but it's not dramatic. Vignetting is well-controlled across the focal length range.

The lens can stop down to f/11 across the focal length range, but I found that sharpness is best between f/4.0 and f/8.0. If a large aperture is desired in bright conditions, rather than stopping the lens down, the RX100 IV has a built-in 3-stop neutral density filter that can be used to reduce the amount of light that reaches the sensor. The lens also produces a pleasing out-of-focus area with its seven-bladed aperture iris. The RX100 IV can focus fairly close as well, capable of close-focusing to just under 2 inches (5cm) at the wide ends of the lens and just under 12 inches (30cm) at the long end of the lens.

A small but capable camera out in the field

The RX100 IV generally handles well out in the field. The automatic shooting modes all work well and allow you to easily get excellent results. Despite being small and not having a wealth of external controls, the RX100 IV also allows as much manual control as you desire, including a fully manual exposure mode that utilizes both the lens control ring and control wheels on the camera for aperture and shutter speed control. If you want to manually focus as well, the lack of a second dial on the camera becomes problematic. In this case, you have to choose what the control dial on the back of the camera will control by pressing down on the control dial and switching between shutter speed and aperture.

There are a couple of particularly nice features to help improve usability and speed up making settings adjustments in the absence of a touch screen and without a lot of manual controls and dials. Firstly, there is the function (Fn) button, which brings up a table of 12 setting shortcuts, all of which can be customized. The default function arrangement worked fine for me and provided quick access to important camera settings such as white balance, autofocus mode, and the autofocus area mode. There is also a display mode called the "Quick Navi" screen. The Quick Navi screen provides an overview of relevant camera settings and provides the Fn menu along the right side of the display. Secondly, there's a customizable C button on the back of the camera below the control dial. You can assign any one of a very long list of functions to this button.

The built-in pop-up electronic viewfinder is a big upgrade from the RX100 III's electronic viewfinder. The 0.39" XGA OLED viewfinder has 2,359,296 dots, compared to the 1,440,000 dots of the RX100 III's electronic viewfinder. The viewfinder is deployed via a small switch on the left side of the camera body and requires you to pull part of it toward you to use, which then has to be pushed back in before you can push the viewfinder back down into the camera body. Although small and having only 0.59x magnification, the viewfinder works well and the pop-up design is impressive.

The RX100 IV offers standard exposure modes, including manual, aperture priority, shutter priority, and program modes on the mode dial. There is also Auto (which offers the choice between Intelligent Auto and Superior Auto), HFR (high frame-rate capture), Scene Selection, Panorama, and Memory Recall exposure modes on the mode dial as well. The RX100 IV works so well in its partially- and fully-automatic shooting modes due in large part to good metering performance. The RX100 IV offers multi-segment, center-weighted, and spot metering options. Unfortunately, spot metering is not tied to the AF point, but is rather fixed in the center of the frame. Multi-segment metering does a good job of evaluating the entire scene and choosing a good exposure. When the camera is not delivering the desired exposure, exposure compensation is easily accessed via either the function menu or by pressing down on the control wheel. White balance metering also performs well and the RX100 IV offers a large variety of white balance presets when more control is desired.

When shooting in fully automatic mode, the control ring can be used to change the focal length of the lens. There is a focal length scale that pops up when rotating the ring with labeled marks at 24, 28, 35, 50, and 70mm focal lengths. In other modes, the control ring is used to control different options, including aperture, shutter speed, ISO, focal length, or focus. It is difficult to be precise when using the control ring, as I mentioned earlier, because it rotates so smoothly and options are cycled through quickly.

Panorama mode works well on the RX100 IV. The camera does a good job at creating a seamless transition throughout the scene and the final images are processed quickly. The quality is quite good, although images are only 1,856 pixels tall when making a traditional horizontal panorama (the shortest dimension is 2,160 pixels when making a vertical panorama), so they aren't particularly high resolution. HDR shooting works well, too. HDR is activated through the function menu or the camera's menu when recording JPEG files. HDR can be set to auto or you can select an EV amount from 1 through 6 EV. The camera does a good job of quickly assembling an HDR image and it is easy to get a sharp image even when shooting hand-held.

The RX100 IV offers various Creative Styles and Picture Effects. The Creative Styles, such as vivid, neutral, black and white, and more, are all customizable. I liked using vivid with +1 Contrast, +1 Saturation, and +1 Sharpness to get vibrant and pleasing JPEG files straight from the camera. The black and white Creative Style works well too. The RX100 IV also offers Picture Effects, such as Toy Camera, Pop Color, Partial Color, High Contrast Monochrome, and more. I don't particularly care for these sorts of effects, but it's never a bad thing to have these options for those who enjoy them.

The RX100 IV's SteadyShot optical image stabilization works very well. I was able to handhold the camera and get sharp images at 24mm with shutter speeds as low as 1/10s. At 70mm, I was able to get sharp images at shutter speeds as low as 1/20s, but 1/30s shutter speeds delivered more consistently sharp results. The RX100 IV has improved Auto ISO capabilities that allow you to select minimum shutter speed. In addition to being able to select a minimum shutter speed, you can also change how quickly ISO changes as the necessary shutter speed for the conditions changes. Auto ISO can be set to faster/fast, which means that ISO sensitivity will change at shutter speeds faster than the 'standard' setting to prevent camera shake and blurring. If you're photographing subjects that don't require fast shutter speeds, you can set the auto ISO to slow/slower and the ISO sensitivity will change at shutter speeds slower than 'standard' so that you can shoot images with lower noise than the other auto ISO settings. The difference in shutter speed at which the ISO sensitivity starts to change between faster, fast, standard, slow, and slower is 1 EV. With the RX100 IV's great image stabilization, I wouldn't hesitate to opt for the slow/slower setting when not photographing moving subjects.

An area of concern that I have with using the RX100 IV is its limited battery life. When using the display, the RX100 IV is rated at 280 shots. When using the viewfinder, it's rated at only 230 shots. When recording occasional video, adjusting settings, and taking burst images, the battery drains quite. If I were planning to have the camera with me all day, I'd definitely invest in a spare battery to have fully charged and ready to go.

Quick and accurate autofocus in a variety of shooting conditions

The RX100 IV offers impressive autofocus performance. AF is quick and accurate across a variety of conditions, including low light. The Fast Intelligent AF System that the RX100 IV uses is upgraded from the RX100 III. The RX100 IV uses contrast detection autofocus, so situations of very low contrast can cause some issues and slow down autofocus performance, but the camera is generally quick and handled most of the situations I encountered very well.

There are numerous autofocus area options, including wide, center, flexible spot, expanded flexible spot, and lock-on AF, with the latter three offering adjustable size options. Wide autofocus area works well, with the camera choosing the subject and appropriate autofocus point(s) automatically from across the entire frame. I most often utilized the flexible spot AF area mode, however, changing the size and position of the spot as needed. Perhaps it's because I've used a large number of touchscreen cameras lately, but the use of a touchscreen for moving the AF area around the frame is often a quick and convenient way to shoot, and its a shame that the RX100 IV doesn't offer this convenience. Instead, you need to press the center button, move the autofocus point around the frame using the control wheel, and then press the center button again. While it's excellent that the autofocus points are numerous and cover such a large portion of the frame, it does mean that it can be a lengthy process to change the flexible spot from one area of the frame to another.

There are four autofocus drive mode options, AF-S, AF-C, DMF (direct manual focus), and manual focus. Given the camera's good autofocus performance, it's not surprising that the AF-S focus mode works very well. Continuous autofocus performance through the AF-C mode works well, too, managing to stay on the subject quite well during my testing when using flexible spot autofocus. Lock-on AF, on the other hand, is less impressive. It can work really well at times, but I found that it is too inconsistent to be relied upon. Lock-on AF (wide) works well when the camera is able to accurately identify the subject before you start shooting. If this is the case, focus stays on the subject quite well so long as it doesn't move too quickly or the lighting conditions do not change dramatically. Wide AF has a tendency to lock onto the brightest or highest contrast subject, so this is something to keep in mind particularly when continuously shooting. Center AF mode works fine, but the same performance can be achieved using Flexible Spot, which naturally has a lot more versatility. I found that when lock-on AF (wide) works well, it's similar to lock-on AF (flexible spot), but flexible spot is more consistent across a variety of conditions. When everything works correctly, lock-on AF is very impressive but a general lack of consistently fast performance is the only thing holding it back from being excellent.

In low light, the RX100 IV impressed me. Given the camera's use of contrast detection AF points, I expected low light AF performance to be a problem area, but like the camera's continuous autofocus performance, its low light autofocus performance was a pleasant surprise. Having not used any of the previous RX100 cameras, I can't speak to whether or not this is an area of improvement, but I found the RX100 IV to perform better than similar style cameras that I've used in the past at both being able to achieve focus in dim conditions and also the speed with which the RX100 IV can achieve focus in dim conditions.

Overall, the RX100 IV's autofocus performance is impressive. Despite using contrast-detection only, the RX100 IV performs well in both low-light and low-contrast conditions. Continuous autofocus performance is quite good as well, although not as consistently good as AF-S performance.

Impressive image quality at higher ISOs

The RX100 IV feels well-suited for low light shooting, as its high ISO performance is impressive when recording both RAW and JPEG files. With RAW images, visible noise starts to become apparent around ISO 800. Detail and contrast still remains very good at ISO 800, however. Visible noise gets quite a bit more apparent at ISO 1600 and contrast starts to noticeably decrease, particularly when looking at deep blacks. ISO 3200 just continues to increase the issues that I saw at ISO 1600, with noise becoming very noticeable and contrast continuing to decrease. ISO 3200 is the limit where I would use RAW files for large-format applications such as 16 x 20 prints or full-size digital files because the files retain a good amount of detail despite the high visible noise. ISO 6400 RAW files are very noisy and I wouldn't use them for anything beyond small web viewing because of the loss of detail. At ISO 12800, RAW files have little detail, excessive noise, and not a lot of contrast.

With "standard" in-camera noise reduction, JPEG files become overly smooth at higher ISOs. While the standard noise reduction manages to keep visible noise at acceptable levels for the entire native ISO range of 125-12800, images at and above ISO 1600 take on an odd, smooth appearance with drastically reduced detail and a blotchy appearance to areas that ought to have a consistent appearance, such as the sky. At ISO 3200 and above, JPEG files with standard noise reduction start to look as though they've had a kind of watercolor painting effect applied to them, which is not to my personal taste. When recording JPEG images, there is also an additional expanded ISO option available called Multi Frame NR that combines multiple shots into one ISO 25,600 file. I would not use this setting except for the purpose of documenting something I saw because there is almost no detail in the image files at ISO 25,600.

JPEG images with no noise reduction applied to them retain good detail despite high levels of visible noise. For me, the best balance between reducing noise and maintaining an acceptable overall appearance is the "low" noise reduction setting. High ISO images captured with low noise reduction are only slightly less noisy than their RAW counterparts, but they still contain decent detail and contrast. If I were in a situation where I had to shoot above ISO 3200 and wanted to be able to use the files straight from the camera for large prints or to crop them extensively, I'd opt to use JPEG files with low noise reduction applied to them.

Like the RX100 III, the RX100 IV does not have a hot shoe. The built-in flash of the RX100 IV is quite handy, despite its small size with a range of approximately 0.4 to 10.2 meters at 24mm using auto ISO. At 70mm, the flash range is 0.4 to 6.5 meters. The flash works well as a fill flash, even in bright conditions and has a max flash sync of 1/2000s.

Overall, the RX100 IV handles well in low light and both the display and the EVF work great in dim light. As I discussed in the autofocus section, the RX100 IV's ability to autofocus in low light is quite good. Taking into account the f/1.8-2.8 lens and the RX100 IV's impressive results at high ISOs, I found that the RX100 IV is great in low light for a compact-class camera.

New sensor brings impressive speed

The RX100 IV uses the same BIONZ X image processor that is found in the RX100 III, but the new sensor allows for improved high-speed shooting performance. With better data throughput, the RX100 IV can continuously shoot full-size JPEG files at 16fps. There is a catch, however, as the RX100 IV cannot capture JPEG files at 16fps without locking the autofocus to whatever it was when the first frame was captured. Fortunately, exposure variables are unlocked in this Speed Priority Continuous Mode. When recording RAW and RAW+JPEG files in speed priority continuous mode, the RX100 IV can record bursts of 28 and 24 images respectively at 8.6fps, according to IR lab test results. With full autofocus capabilities, the RX100 IV can capture bursts at up to 5.5fps, which is nearly double the RX100 III's 2.9fps continuous shooting with full autofocus

Maximum shutter speed has also seen a dramatic increase with the new sensor design. The RX100 IV can capture images using its electronic shutter at shutter speeds up to 1/32000s. It's nice to have the electronic shutter capabilities when shooting at the bright, maximum aperture in very bright conditions. By default, the camera is set to automatically switch to the electronic shutter for shutter speeds exceeding the 1/2000s limit of the mechanical shutter, although you can use either shutter exclusively if desired.

The camera is quick to respond to changes in settings and the menus are responsive. The RX100 IV processes image files quickly as well. The camera can be a little slow to process large bursts, but most still images, including HDR images, are processed quickly. Standard video files are processed quickly, but high frame rate slow motion videos take however long the final video will be in length to process. For example, a 4 second (shooting time priority) clip at 960fps that will be displayed at 24p will take 2 minutes and 45 seconds to process.

4K and high frame video highlight an impressive set of features

Speaking of video, the RX100 IV offers numerous movie features and recording options that are both fun to use and good quality. The RX100 IV can record 4K (UHD) video at up to 30fps and Full HD video at up to 60fps. In addition, the RX100 IV offers some new, very interesting slow-motion video recording options, including slow-motion video at up to 960fps (1000fps if the camera is set to the PAL region).

The RX100 IV has a dedicated movie recording mode on the mode dial, but it can record video in standard shooting modes as well. There is a dedicated movie record button on the back of the camera to the right of the thumb grip that is used to start and stop movie recording throughout all shooting modes. In addition to the dedicated movie record button, the camera body has a stereo mic and HDMI out. HDMI can be used to output an uncompressed 4K video signal to an external device (even while recording 4K video it simultaneously, though the LCD screen on the camera will go black during recording).

As far as using the RX100 IV for video is concerned, it's user friendly. One issue that I experienced multiple times after recording an assortment of video clips is that the camera's internal temperature became too high and it shut down. It was sunny and 75 degrees outside, certainly not particularly unusual conditions for using a camera. I was able to start using the camera again after only a few minutes each time, but it was still concerning. The camera limits 4K record time to 5 minute clips at a time, most likely for heat-related issues, as well.

The camera performs very well when recording video overall. The camera meters exposure well and makes quick adjustments when lighting conditions change during recording. Exposure compensation can be used when recording video, if necessary. The focal length changes quietly and smoothly as well. Changes in aperture can be made during recording without any noticeable change in exposure, provided that the camera is set to an automatic mode. Autofocus performance is good, although in low-light the camera tends to hunt for focus. In good light, autofocus is quick and accurate. Unfortunately, you cannot use lock-on AF when recording video. The 4K videos that the RX100 IV produces are very sharp and impressive in detail. Although when shooting 4K video, or recording in XAVC format at all, the monitor brightness is locked at +/- 0, which can cause difficulties when recording video in bright conditions.

When using the High Frame Rate (HFR) mode on the mode dial, the RX100 IV can record various slow motion video. HFR clips are all captured at sub-1080p resolutions, but they are up-sampled to 1080p resolution and saved in the XAVC S format with selectable playback speed options of 24, 30, and 60fps. The clips are only 2 or 4 seconds long, but when played back, they are considerably longer because of the high frame rate of the capture. Frame rate capture options for NTSC come three-fold: 240, 480 or 960fps. You have the choice of quality or shoot time priority, with the duration of recording being 2 or 4 seconds respectively. Shoot time priority decreases the initial recording resolution in exchange for twice as long of a recording. For example, a video recorded with quality priority at 960fps is recorded at a resolution of 1,136 x 384 pixels whereas a shoot time priority video at 960fps is recorded at a resolution of 800 x 270 pixels. At these higher frame rates, video quality is noticeably low resolution, but the novelty of it is very high. It's a lot of fun to take slow-motion video.

The RX100 IV is a very capable camera for video and packs a lot of performance and features into a small camera body. . Being able to capture high-quality video files in a wide variety of conditions at UHD resolutions is impressive. Further, for those using the RX100 IV as part of a multi-camera video shoot, or just those who want extensive control over video files, there are also a variety of Picture Profiles, including S-Log, available for use in both stills and video. Being able to capture video at frame rates approaching 1000fps is enjoyable, even if the actual quality isn't particularly high.

Mobile app delivers good features, but update the camera first

By default, the RX100 IV comes with the Smart Remote Embedded application, which offers remote control over its built-in Wi-Fi. The connection process over Wi-Fi is fairly standard, requiring me to start the application from within the camera's menu, select the camera via my mobile device's Wi-Fi settings, and then launch Sony's PlayMemories Mobile application. The connection process via NFC is supposed to be much simpler, letting you simply tap your NFC-enabled device and the camera together for an automatic app download and pairing between the mobile device and camera.

This default Smart Remote Embedded application does not offer much functionality at all, allowing only control of exposure compensation and focal length. You can't use touch focus, touch shutter, or change any other important camera settings. You can set a self-timer and change focus mode through the application's settings page, but that's about it.

If you want the Smart Remote Control application on the RX100 IV, which is much more functional than the default application, you have to download it to your camera via a Wi-Fi access point or install it to your camera from your PC. In either case, you have to have a Sony Entertainment Network account. The account and application are both free, but the fact that you have to go through the process rather than the camera having Smart Remote Control installed from the get-go is perplexing. There are additional applications that you can install as well, but many of them must be purchased, such as Time-lapse ($10), Star Trail ($10), Angle Shift Add-on ($5), and Motion Shot ($5).

Smart Remote Control is essentially the remote control application I'm used to seeing as standard on other cameras. It offers numerous controls over camera settings such as shutter speed, aperture, exposure compensation, and ISO via an on-screen slider menu. Focal length is controlled by tapping W or T on the right side of the mobile app's screen. Via the settings menu you can change white balance, self-timer, focus mode, touch shutter, review image size, live view quality, and location and display options. Default live view image quality is okay, but "image quality priority" is much better. In either case, the connection is consistent and on par with other mobile applications and cameras I've used. Touch focus and touch shutter are both nice options to have as well, which like many of above features, are absent in the default Smart Remote Embedded application. It is helpful that physical changes made to the exposure mode of the camera are also reflected in the application without having to restart the connection, which is an issue that I often have with other cameras and remote control applications.

Basically, the Smart Remote Embedded application is very limited and the Smart Remote Control application is good, so I would highly recommend downloading the Smart Remote Control application to your RX100 IV if you intend on using your mobile device to control the camera.

Sony RX100 IV Field Test Summary

The positives far outweigh the negatives

What I like:

• Compact camera body that can fit into a pocket
• Pop-up EVF is sharp and clever
• High-quality lens with a wide maximum aperture throughout the focal length range
• Very good image quality
• 4K video recording
• HFR video recording is a lot of fun to use even though the resolution is low

What I dislike:

• Despite the high quality of the lens, 24-70mm isn't a robust range
• A touchscreen would make the camera much easier to navigate and faster to use
• Battery drains rather quickly
• Default in-camera Wi-Fi app lacks features; need to install additional (free) app

The Sony RX100 IV continues in the excellent tradition of the RX100 series by delivering fantastic image quality, but also brings numerous new and exciting features to make the RX100 IV a great compact camera. While its street price of around $950 USD is quite high for a pocket cam, you get a lot of camera for the money. The new stacked sensor allows for a dramatic increase in speed throughout the camera. The RX100 IV possesses the versatility to be used as an excellent point and shoot, a fully-manual camera, or something in between the two extremes. While the built-in 24-70mm f/1.8-2.8 lens does deliver excellent results, its range is decidedly limited for my taste and what I like to shoot. If this focal length range will work for you and your photography, then I can't think of a better option in this class of camera than the RX100 IV.