Comparing Panasonic GH4 and Sony a7s
Comparing Panasonic GH4 and Sony a7s
In terms of video features, the Sony Alpha 7S has one of the more comprehensive offerings on the market. However, it can't keep pace with the Panasonic GH4, which benefits from several more generations of development, and the feedback from professional video shooters.
Here's a compartive list of the features offered by the two cameras for videographers.
The Sony XLR-K1M adapter adds two XLR mic inputs with individual control over input levels. This unit connects to the camera's Multi-Interface connector in its hotshoe and allows the connection of line-level or mic-level (with or without provision of 48V phantom power).
As you can see from the symmetrical seimens stars,
both cameras are creating their video from the same number of
horizontal and vertical lines (the line skipping method some other
cameras use results in a lower vertical sampling frequency than the
horizontal sampling frequency - meaning you get lower vertical
resolution than you'd expect).
However, while both cameras show similar amounts of detail, the Sony's output has virtually none of the interference patterns that the GH4 shows. The difference between the two is aliasing - frequencies higher than the camera can sample appearing, falsely, as low-frequency patterns.
Panasonic, in its 1080 mode, is pixel-binning - combining data from multiple pixels before reading them out. The Sony, by comparison is oversampling the scene (reading out a 4K region of the sensor) then processing that data before downsizing. Indeed you can get a similar result from the Panasonic by applying a slight guassian blur to the 4K image before downsizing to 1080.
This highlights several things. Firstly that the Sony can output a 4K signal from the same crop as it used for 1080, whereas the Panasonic uses a smaller crop for its 4K footage. This suggests the Panasonic could probably produce similar video quality to the Sony if it could output 1080 footage made from the 4K readout region of the sensor.
The GH4 carries on most of the GH3's controls but gives them an additional generational polish, which is no bad thing. The GH3 was a well-designed stills camera, with a substantial grip, twin dials and the level of direct control that you'd expect to encounter on a mid-level DSLR. White balance, ISO and Exposure compensation buttons are arranged across the top of the camera, while drive and autofocus modes both get dedicated controls.
Sadly, despite having a dedicated Exposure Comp button, the GH4 doesn't allow its use when using Auto ISO in Manual exposure mode. This means that, while it is possible to manually set shutter speed and aperture and let the camera select an appropriate ISO setting, you can't have any control over image brightness. This minor shortcoming in terms of stills shooting - the majority of cameras still don't get this right and most shooters don't mind - but it represents a much greater missed opportunity when shooting movies.
For the most part, though, the GH4 is a very pleasant camera to shoot with. A combination of touchscreen AF point selection and some fairly interesting custom point selection modes give plenty of options to help ensure the camera focuses on the correct subject. The company's innovative DFD technology that estimates the distance to an out-of-focus object based on an understanding of each lens's optical characteristics does a good job of improving continuous AF performance.
The GH4's five physical customizable buttons, combined with an
additional five touchscreen positions make it possible to gain easy
access to all the shooting options you might want. For instance, if you
prefer to use the four-way controller to position the AF point when your
eye is to the viewfinder, you can set one button to be 'Focus Area Set'
to avoid the multiple button presses of the 'AF Mode/MF' option (The
default setting for Fn 3).
The GH4 also has one of the smartest combinations of touchscreen and viewfinder we've seen. The option exists to allow you to continue to use the touchscreen to position the AF point while looking through the viewfinder. More importantly, you get to choose whether touching the screen makes the AF point jump to the corresponding position in the viewfinder (Exact mode) or whether it merely moves from its current position, based on the direction you swipe your finger (Offset mode).
The default Panasonic Q.Menu isn't the prettiest system - ranging 13 settings along the top and bottom of the screen. More awkwardly, pressing left and right scrolls through them, meaning you constantly jump between options at the top of the screen (which you need to press 'down' to adjust) and the bottom (where you need to push the 'up' direction), which can be oddly disorientating if you're trying to operate the camera quickly.
Thankfully there's also a menu setting that instead gives you a
customizable Q.Menu. This lets you drag-and-drop settings into two pages
of five on-screen buttons. This instance of the Q.Menu always re-opens
on the previously-used page, so it can be useful to set one page up for
stills options and the other for movies.
While on some cameras the ability to assign functions to a touchscreen menu can make it feel like the camera hasn't got enough hard buttons, on the GH4 it feels like a more conscious choice. The use of the touchscreen can be made an integral part of the camera's shooting experience. Engage the camera's 'Silent Operation' mode in the video mode and a tab is added to the touchscreen controls that allows swiped control of settings such as gain, exposure comp and mic level.
We were a little disappointed to find you can't set Auto ISO when shooting manual exposure video. We suspect many first-time videographers would like to be able to specify the shutter speed and aperture and let the camera adjust sensitivity (ideally with exposure comp to be able to control brightness). Instead you have no choice but to continue to manually adjust ISO throughout a shoot, or switch to either S or A mode and lose control over either depth-of-field or the way motion is represented.
The GH4 is the fourth generation of stills/movie hybrid cameras that Panasonic has made and the company makes a big play of how carefully it listened to filmmakers when developing the latest model. The result is a camera with an extensive range of features that will be alien to most stills shooters but recognized and welcomed by professional and semi-professional videographers.
Despite this care and attention to offer a product acceptable to professionals, the GH4 doesn't offer a tone curve as 'flat' as the logarithmic response curves available on the Sony or Canon's cameras. Log curves are used to incorporate as much of the camera's dynamic range into the footage as possible - giving greater flexibility for color grading during post processing. It's also not possible to import or significantly adjust the GH4's color profiles, so there's no way to add this option. As such, although the GH4 offers the fairly flat 'Cinelike D' profile (with the option to further lower the contrast), it's not possible to match the Sony's very wide dynamic range footage for maximum flexibilty in post.
To add to the complication, the GH4 can be booted in three different system frequency modes: 59.94, 50 and 24fps. The frame rates available (along with the Synchro Scan and Variable Frame Rate options) will vary depending on which mode the camera has engaged.
In 59.94Hz mode, all frame rates are NTSC multiples (frame rates
reported as 60p are actually 59.94p, 30p is 29.97p and 24p is 23.98p). *Variable frame rate recording is available.
More pro-orientated features include time codes, markers, and Picture Profiles, all of which will be discussed in detail in the coming weeks. For amateur videographers, though, the GH4 still makes it possible to access a lot of the camera's capabilities. Here we'll discuss the more fundamental features that all users are likely to find useful.
The GH4 allows the use of some functions while recording but doesn't give access to the Q.Menu or main menu The other key feature to discover in the GH4 is 'Silent Operation' mode, which adds a video-specific 'tab' to the right-hand side of the camera's touch screen, rather than having to turn any dials, which could be captured by the outboard microphone.
Like the a7S, the GH4 offers control over audio capture level (expressed in dB), which can be adjusted, during recording, using the touchscreen if Silent Operation mode is engaged. In common with the Sony you get the option of whether then headphone output is realyed live or delayed to match the captured footage. A three-level Wind Cut filter is available, with Off and Auto settings along with a Mic Level Limiter which reduces the recording volume if the sound gets too loud.
The GH4 can output either a 'clean' signal or one with with settings information overlayed, across its HDMI socket. Unlike the Sony, it provided the choice of 8 or 10-bit 4:2:2 output. 10-bit mode is designed for used with an external recorder, so the settings overlay is switched off. The camera cannot record internal video at the same time as outputting a 10-bit signal over HDMI.
 |
| Panasonic GH4 |
 |
| Sony a7s |
In terms of video features, the Sony Alpha 7S has one of the more comprehensive offerings on the market. However, it can't keep pace with the Panasonic GH4, which benefits from several more generations of development, and the feedback from professional video shooters.
Here's a compartive list of the features offered by the two cameras for videographers.
| Panasonic GH4 | Sony Alpha 7S | |||
|---|---|---|---|---|
| Max video Res (Internal) | Cinema 4K (4096 x 2160) | Full HD (1920 x 1080) | ||
| Highest bitrate 1080 video | • 200Mbps 24p • 200Mbps 60p |
• 50Mbps 24p • 50Mbps 60p |
||
| Movie-targeted color modes | • Cinelike D and Cinelike L (Hue) |
• Picture Profiles, SLog2 (Black Gamma, Knee, Color Phase) |
||
| Black level control | • Master Pedestal (-15 to +15) | •Black Level (-15 to +15) | ||
| Luminance range options | • 0-255, 16-255, 16-235 | • No | ||
| Audio level control | • -12 to +6dB | • 0-31 | ||
| Mic level display | • Optional | • Optional | ||
| Sound output | • Realtime/Rec Sound | • Live/Lip Sync | ||
| Peaking | • 2 Levels • 3 Colors |
• 3 Levels • 3 Colors |
||
| Zebra | • Two presets • 105% – 50% |
• 100+ – 70 | ||
| Markers | • Center • Guide Lines |
• Center • Aspect • Safety Zone • Guideframe |
||
| Synchro Scan | • Yes | • No | ||
| HDMI Output | • FHD 4:2:2 8-bit/10-bit* • 4K 4:2:2 8-bit/10-bit* |
• FHD 4:2:2 8-bit • 4K 4:2:2 8-bit |
||
| Clean HDMI Output | • Optional | • Optional | ||
| Time Code | • Free Run / REC Run • Includes dropped-frame option for NTSC (59.94fps) modes |
• TC / UC • Free Run / REC Run • Includes dropped-frame option for NTSC (59.94fps) modes |
||
| Time/Gain display methods | • SEC/ISO • ANGLE/ISO • SEC/dB |
• SEC/ISO | ||
| Color Bars | • SMPTE • EBU • ARIB |
• No | ||
| Variable Frame Rate | • 2fps (1200%) high-speed - 96fps (25%) slow motion | • No (Though 720p footage can be shot at 120p and 100p then used as slow-motion footage with suitable editing software) |
*Internal recording not available with 10-bit HDMI mode.
There's a fair amount there that no other mainstream stills/video
camera offer. In addition, both companies sell accessory units that
offer industry-standard connections for audio and, in Panasonic's case,
video.The Sony XLR-K1M adapter adds two XLR mic inputs with individual control over input levels. This unit connects to the camera's Multi-Interface connector in its hotshoe and allows the connection of line-level or mic-level (with or without provision of 48V phantom power).
The Panasonic DMW-YAGH module is rather more extensive
addition, adding not just XLR inputs (with the same line, mic, phantom
power mic options), but also features four SDI connectors (2 x HD and 2 x
3G), allowing 4K, 1080p60 and 1080p30 output, in various combinations.
The YAGH also includes a timecode input socket and full-sized HDMI out,
rather than the camera's mini HDMI connector. The unit is powered by a
4-pin XLR 12V DC connector.
Video sampling / quality
Here we can see how the GH4 and a7S compare, in terms of the resolution of the footage they can shoot. Both were recorded internally at the camera's highest quality settings.
Go to full screen mode
Video Stills Comparison
Image comparison tool
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Download: JPEG (929.7KB)
However, while both cameras show similar amounts of detail, the Sony's output has virtually none of the interference patterns that the GH4 shows. The difference between the two is aliasing - frequencies higher than the camera can sample appearing, falsely, as low-frequency patterns.
Panasonic, in its 1080 mode, is pixel-binning - combining data from multiple pixels before reading them out. The Sony, by comparison is oversampling the scene (reading out a 4K region of the sensor) then processing that data before downsizing. Indeed you can get a similar result from the Panasonic by applying a slight guassian blur to the 4K image before downsizing to 1080.
This highlights several things. Firstly that the Sony can output a 4K signal from the same crop as it used for 1080, whereas the Panasonic uses a smaller crop for its 4K footage. This suggests the Panasonic could probably produce similar video quality to the Sony if it could output 1080 footage made from the 4K readout region of the sensor.
The GH4 carries on most of the GH3's controls but gives them an additional generational polish, which is no bad thing. The GH3 was a well-designed stills camera, with a substantial grip, twin dials and the level of direct control that you'd expect to encounter on a mid-level DSLR. White balance, ISO and Exposure compensation buttons are arranged across the top of the camera, while drive and autofocus modes both get dedicated controls.
Sadly, despite having a dedicated Exposure Comp button, the GH4 doesn't allow its use when using Auto ISO in Manual exposure mode. This means that, while it is possible to manually set shutter speed and aperture and let the camera select an appropriate ISO setting, you can't have any control over image brightness. This minor shortcoming in terms of stills shooting - the majority of cameras still don't get this right and most shooters don't mind - but it represents a much greater missed opportunity when shooting movies.
For the most part, though, the GH4 is a very pleasant camera to shoot with. A combination of touchscreen AF point selection and some fairly interesting custom point selection modes give plenty of options to help ensure the camera focuses on the correct subject. The company's innovative DFD technology that estimates the distance to an out-of-focus object based on an understanding of each lens's optical characteristics does a good job of improving continuous AF performance.
| Functions that can be applied to the GH4's function buttons | ||
|---|---|---|
| • Wi-Fi • Q/Menu • LVF/Monitor Switch • AF/AE Lock • AF-On • Preview • One Push AE • Touch AE • Level Gauge • Focus Area Set • Zoom Control • 1 Shot Raw + JPEG • 1 Shot Spot Metering • Cursor Button Lock • Photo Style • Aspect Ratio • Picture Size • Quality |
• AFS/AFF • Metering Mode • Burst Rate • Auto Bracket • Self Timer • Highlight Shadow • i.Dynamic • i.Resolution • HDR • Electronic Shutter • Flash Mode • Flash Adjust • Ex. Tele Conv. • Digital Zoom • Stabilizer • Motion Pic. Rec Format • Motion Pic. Rec Quality • Variable Frame Rate |
• Picture Mode • Synchro Scan • Time Code Display • Mic. Directivity Adjust • Color Bars • Silent Mode • Peaking • Histogram • Guide Line • Zebra Pattern • Monochrome Live View • Rec Area • Video-Priority Display • Step Zoom • Zoom Speed • Touch Screen • AF Mode/MF • Restore to Default |
The GH4 also has one of the smartest combinations of touchscreen and viewfinder we've seen. The option exists to allow you to continue to use the touchscreen to position the AF point while looking through the viewfinder. More importantly, you get to choose whether touching the screen makes the AF point jump to the corresponding position in the viewfinder (Exact mode) or whether it merely moves from its current position, based on the direction you swipe your finger (Offset mode).
The default Panasonic Q.Menu isn't the prettiest system - ranging 13 settings along the top and bottom of the screen. More awkwardly, pressing left and right scrolls through them, meaning you constantly jump between options at the top of the screen (which you need to press 'down' to adjust) and the bottom (where you need to push the 'up' direction), which can be oddly disorientating if you're trying to operate the camera quickly.
| Changing the Q.Menu setting in the Custom menu (Page 7, Option 2), from Preset to Custom gives a customizable menu. This custom version offers two pages, each with five positions into which your chosen settings can be placed. Pressing the 'Q' button at the bottom left allows you to change them. |
|
|---|---|
| • Photo Style • Picture Setting • Quality • AFS/AFF • Metering Mode • Burst Rate • Auto Bracket • Self Timer • i.Dynamic • i.Resolution • HDR • Electronic Shutter • Flash Mode • Flash Adjust • Ex. Tele Conv. • Digital Zoom • Stabilizer • Motion Pic. Rec Format |
• Motion Pic. Rec Quality • Variable Frame Rate • Picture Mode (Movies/Stills) • Synchro Scan • Time Code Display • Silent Mode • Peaking • Histogram • Guide Line • Zebra Pattern • Monochrome Live View • Rec Area • Video-Priority Display • Step Zoom • Zoom Speed • Touch Screen • AD Mode |
Video
Where the GH4's ergonomics shine, though, is on the video side of things. It's clear Panasonic has spent considerable time thinking about camera operation by videographers, which makes a pleasant change from those models that simply have a red [REC] button and the option to turn on a wind-cut filter.While on some cameras the ability to assign functions to a touchscreen menu can make it feel like the camera hasn't got enough hard buttons, on the GH4 it feels like a more conscious choice. The use of the touchscreen can be made an integral part of the camera's shooting experience. Engage the camera's 'Silent Operation' mode in the video mode and a tab is added to the touchscreen controls that allows swiped control of settings such as gain, exposure comp and mic level.
We were a little disappointed to find you can't set Auto ISO when shooting manual exposure video. We suspect many first-time videographers would like to be able to specify the shutter speed and aperture and let the camera adjust sensitivity (ideally with exposure comp to be able to control brightness). Instead you have no choice but to continue to manually adjust ISO throughout a shoot, or switch to either S or A mode and lose control over either depth-of-field or the way motion is represented.
The GH4 is the fourth generation of stills/movie hybrid cameras that Panasonic has made and the company makes a big play of how carefully it listened to filmmakers when developing the latest model. The result is a camera with an extensive range of features that will be alien to most stills shooters but recognized and welcomed by professional and semi-professional videographers.
Despite this care and attention to offer a product acceptable to professionals, the GH4 doesn't offer a tone curve as 'flat' as the logarithmic response curves available on the Sony or Canon's cameras. Log curves are used to incorporate as much of the camera's dynamic range into the footage as possible - giving greater flexibility for color grading during post processing. It's also not possible to import or significantly adjust the GH4's color profiles, so there's no way to add this option. As such, although the GH4 offers the fairly flat 'Cinelike D' profile (with the option to further lower the contrast), it's not possible to match the Sony's very wide dynamic range footage for maximum flexibilty in post.
Video recording options (internal)
The GH4 can output and capture video in a dizzying selection of codecs, bit rates and frame rates (with a choice of audio codec as well, in the case of MP4). Most of these modes use the IPB compression system that records 'key' frames at regular intervals and only retains information about any changes between those key frames. The GH4 also offers 'All-I' capture modes that treat every frame as key frame, retaining full detail about every frame.To add to the complication, the GH4 can be booted in three different system frequency modes: 59.94, 50 and 24fps. The frame rates available (along with the Synchro Scan and Variable Frame Rate options) will vary depending on which mode the camera has engaged.
| System Frequency Mode 59.94Hz / 50Hz | ||
|---|---|---|
| Format | AVCHD / MOV / MPEG4 | |
| Sizes | • AVCHD (Dolby Digital Audio) 1920 x 1080 60p ~28 Mbps1920 x 1080 60i ~17 Mbps1920 x 1080 30p (60i PsF) ~24Mbps* 1920 x 1080 24p ~24Mbps*• MP4 (AAC Audio) 3840 x 2160, 30p ~100Mbps1920 x 1080, 60p ~28Mbps1920 x 1080, 30p ~20Mbps1280 x 720, 30p ~10Mbps640 x 480 30p, ~4Mbps• MP4 (Linear PCM Audio) 3840 x 2160, 30p ~100Mbps3840 x 2160, 24p ~100Mbps1920 x 1080, 60p ~200Mbps (All-I)1920 x 1080, 60p ~100Mbps1920 x 1080, 60p ~50Mbps1920 x 1080, 30p ~200Mbps (All-I) 1920 x 1080, 30p ~100Mbps*1920 x 1080, 30p ~50Mbps1920 x 1080, 24p ~200Mbps (All-I) 1920 x 1080, 24p ~100Mbps*1920 x 1080, 24p ~50Mbps• MOV (Linear PCM Audio) 3840 x 2160, 30p ~100Mbps3840 x 2160, 24p ~100Mbps1920 x 1080, 60p ~200Mbps (All-I)1920 x 1080, 60p ~100Mbps1920 x 1080, 60p ~50Mbps1920 x 1080, 30p ~200Mbps (All-I) 1920 x 1080, 30p ~100Mbps1920 x 1080, 30p ~50Mbps1920 x 1080, 24p ~200Mbps (All-I) 1920 x 1080, 24p ~100Mbps1920 x 1080, 24p ~50Mbps |
• AVCHD (Dolby Digital Audio)1920 x 1080 50p ~28 Mbps1920 x 1080 50i ~17 Mbps1920 x 1080 25p (50i PsF) ~24Mbps* • MP4 (AAC Audio) 3840 x 2160, 25p ~100Mbps1920 x 1080, 50p ~28Mbps1920 x 1080, 25p ~20Mbps1280 x 720, 25p ~10Mbps640 x 480 25p, ~4Mbps• MP4 (Linear PCM Audio) 3840 x 2160, 25p ~100Mbps1920 x 1080, 50p ~200Mbps (All-I)1920 x 1080, 50p ~100Mbps1920 x 1080, 50p ~50Mbps1920 x 1080, 25p ~200Mbps (All-I) 1920 x 1080, 25p ~100Mbps*1920 x 1080, 25p ~50Mbps• MOV (Linear PCM Audio) 3840 x 2160, 25p ~100Mbps1920 x 1080, 50p ~200Mbps (All-I)1920 x 1080, 60p ~100Mbps1920 x 1080, 60p ~50Mbps1920 x 1080, 25p ~200Mbps (All-I) 1920 x 1080, 25p ~100Mbps*1920 x 1080, 25p ~50Mbps |
| Audio | • Linear PCM (MOV or MP4) / Dolby Digital (AC-3) (AVCHD)/ AAC (MP4) • Stereo audio capture via built-in or optional mic. |
|
| Recordable time | Approx 29 mins for XAVC and AVCHD, 20 minutes for MPEG4 (1440 x 1080) | |
| System Frequency Mode 24Hz | |
|---|---|
| Format | MOV / MPEG4 |
| Sizes | • MP4 (Linear PCM Audio)4096 x 2160, 24p ~100Mbps3840 x 2160, 24p ~100Mbps1920 x 1080, 24p ~200Mbps (All-I)1920 x 1080, 24p ~100Mbps*1920 x 1080, 24p ~50Mbps • MOV (Linear PCM Audio) 4096 x 2160, 24p ~100Mbps3840 x 2160, 24p ~100Mbps1920 x 1080, 24p ~200Mbps (All-I) 1920 x 1080, 24p ~100Mbps*1920 x 1080, 24p ~50Mbps |
| Audio | • Linear PCM (MOV or MP4 / AAC (MP4) • Stereo audio capture via built-in or optional mic. |
| Recordable time | Approx 29 mins for XAVC and AVCHD, 20 minutes for MPEG4 (1440 x 1080) |
Features
The GH4 provides videographers with an impressive set of tools. As you'd expect, you can adjust shutter speed and/or aperture. Sadly, in manual ('M') mode, the camera won't offer Auto ISO, so you can't set your shutter speed and aperture and let the camera deal with providing the correct image brightness. Beginner videographers in particular are likely to miss the simplicity this brings.More pro-orientated features include time codes, markers, and Picture Profiles, all of which will be discussed in detail in the coming weeks. For amateur videographers, though, the GH4 still makes it possible to access a lot of the camera's capabilities. Here we'll discuss the more fundamental features that all users are likely to find useful.
Manual focus and exposure warning displays
The GH4's two main video guides are peaking (which indicates in-focus areas of high contrast on the screen) and zebra pattern, which highlights areas of the scene that exceed a specified brightness threshold.The GH4 allows the use of some functions while recording but doesn't give access to the Q.Menu or main menu The other key feature to discover in the GH4 is 'Silent Operation' mode, which adds a video-specific 'tab' to the right-hand side of the camera's touch screen, rather than having to turn any dials, which could be captured by the outboard microphone.
Like the a7S, the GH4 offers control over audio capture level (expressed in dB), which can be adjusted, during recording, using the touchscreen if Silent Operation mode is engaged. In common with the Sony you get the option of whether then headphone output is realyed live or delayed to match the captured footage. A three-level Wind Cut filter is available, with Off and Auto settings along with a Mic Level Limiter which reduces the recording volume if the sound gets too loud.
The GH4 can output either a 'clean' signal or one with with settings information overlayed, across its HDMI socket. Unlike the Sony, it provided the choice of 8 or 10-bit 4:2:2 output. 10-bit mode is designed for used with an external recorder, so the settings overlay is switched off. The camera cannot record internal video at the same time as outputting a 10-bit signal over HDMI.
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