What is V Log?
Lots of Lumix cameras now offer very flat V-Log and V-LogL Photo Styles that promise better use of the camera’s dynamic range for videographers. Here we discuss what those Photo Styles do and when we might use them
In all types of photography we battle to capture and retain as much information from the scene as possible, so we can create images that look as realistic as we can make them. Unfortunately for photographers our brain and our eyes combine to use a very different method to ‘see’ the world from the way a camera’s sensor works. That makes it an uphill struggle to record enough tones in a photograph so that matches the way our head perceives the scene before us.
When we look at a view without a camera we can see all the detail in the brightest clouds and in the darkest undergrowth because our eyes scan the scene, as though taking multiple exposures, and the brain fits all the information together in one picture. Cameras, unfortunately, don’t work in quite the same way, so we need to find a way to collect all this tonal detail as effectively as possible in one shot.
The image on the left is from a video shot using the Natural Photo Style. While it has done well in such contrasty conditions to retain detail in the brightest parts of the flower, the deep background shadows have turned to black. The frame on the right was shot in V-LogL and, once edited or ‘graded’, offers a softer contrast that reveals far more detail in the extreme tonal values of the image
In still photography we have raw files that allow us to make use of the complete range of tones a sensor is capable of capturing, so bright and dark areas can be recorded with plenty of detail. Videographers also have raw formats, but the consequences of capturing raw images at the frame rates video requires means cameras have to be able to process masses of data and memory devices have to able to receive it. Right now for Lumix cameras, and most other video camera makers, that means using an external video recorder – and it isn’t always possible, practical or desirable to do so.
This panel of frames demonstrates how different Photo Styles allow us to retrieve details in extreme tonal values in post-capture software. The aim was to be able to show the highlight details in the leaf while avoiding a very dark background. The flatter Photo Styles (Flat, Natural and HLG) have done quite well, but the footage recorded in V-Log is clearly much more detailed and produces a nicer result with moderate contrast. Right click to see this panel bigger
Log profiles are something of a happy medium between the bigger files and the hassle of using an external recorder when shooting in ProRes 4:2:2 or ProRes Raw, and the ‘almost finished’ files recorded when using standard in-camera picture profiles, such as the Photo Styles provided in Lumix cameras. When we shoot in the usual Photo Styles our footage mightn’t need very much doing to it at all in post-production, which makes the process of producing a finished video quick and convenient. Sometimes however, the normal Photo Styles don’t have enough dynamic range to capture information evenly in high-contrast conditions so we need some extra help.
The Photo Styles we can use to make the most of the dynamic range of our Lumix cameras are V-Log and V-LogL, as well as the ‘flatter’ Photo Styles such as Natural, Flat and Hybrid Log Gamut (HLG). What V-Log and V-LogL offer though is the best chance of capturing an image that can be manipulated in post-production to allow the brightness and colour changes that might be needed when footage is recorded in extreme conditions.
What actually is V-Log?
V-Log is just another Photo Style, but one designed to produce an image that has flat contrast and low colour saturation. All Photo Styles alter the way the image from the sensor is presented to us, adding contrast and colour characteristics to create a specific look or to match what we expect from certain subject matter. The Landscape/Scenery Photo Style creates deeper shadows and more colour saturation in yellows, reds and blue skies, for example, while Natural tries to create a look that matches what our eyes see – moderate contrast and moderate colour saturation.
Photo Styles that create flatter looks – less contrast and less colour saturation – are good when we want to alter colour and contrast afterwards in post-production, and that’s what V-Log is for. It’s designed to be a very flat profile that lacks very many decisions made by the camera about how the picture should look, which then allows us to take control of all that later.
A frame from the Lumix S5 using V-Log. Straight out of the camera it looks very dull, flat and boring, but it provides an ideal starting point for grading because there are no deep blacks and burnt out whites
Images straight from the camera shot in V-Log don’t look very good at all, but that’s fine as they are designed for those who want to ‘grade’ (‘edit’ in still-photographer speak) them in software to get an atmosphere and style of their own. If you shoot a video in the Vivid Photo Style it is very difficult to change it to anything that isn’t high contrast/punchy colours without banding and broken tones creeping in.
The same frame as above after grading in Davinci Resolve software
Lumix cameras compatible with V-Log
V-Log and V-LogL usually come as paid-for firmware upgrades, but the Photo Style comes pre-installed in the Lumix GH5S, Lumix G100, Lumix G90, Lumix BGH1, Lumix S1H and S5
What’s the difference between V-Log and V-LogL?
In many conditions, even when there is plenty of contrast, V-LogL works brilliantly well to capture a full range of tones. Lumix GH5
The V-Log and V-LogL Photo Styles are much the same but the L in V-LogL stands for ‘Light’, meaning it is adapted to work with the more limited dynamic range (DR) of that specific camera’s sensor. As it is used with cameras with a more restricted dynamic range we won’t get quite the same DR that we’d expect from a camera that offers the full V-Log profile. In short, Lumix G series models that offer Log will use V-LogL while Lumix S-series cameras will provide the full V-Log. Both will deliver a nice flat image that will be capable of representing a wider range of tones than we’d get with regular Photo Styles, but the full V-Log offers an extra step of flexibility.
In extreme situations, such as when needing to preserve details in both the back of the white cow and the underside of the black cow, the additional stop of dynamic range offered by the full V-Log is needed. Frame from a clip shot on the Lumix S1H
In normal conditions footage shot in these profiles may be identical-looking once graded, but it is in scenes that contain areas with dramatically different brightness values that the advantages of the full V-Log come into their own. Full V-Log holds on to more highlight detail and allows shadows to be lifted a little more without us discovering that the darkest tones are actually just recorded as featureless black.
That the two Photo Styles are so similar is excellent news for those using both G/GH and S series cameras, as footage from both can be seamlessly cut together and the same LUTs (articles on LUTs coming soon!) can be used to produce the same looks.
The influence of bit depth
Not all Photo Styles are equal, so we need to pay attention to make sure we are on target to get the best out of the features we have. Shooting V-Log or V-LogL in 8-bit won’t give us a dramatic advantage over shooting with the regular flatter Photo Styles because 8-bit video has a more restricted capability to capture a wide dynamic range. There will definitely be some advantage over the other Photo Styles, but your ability to retain highlights will be only slightly better.
Although 8-bit V-LogL has done really well in this extremely high contrast scene, in places the white of the ice cream and the lady’s hair is burnt out
The key difference between 8-bit and 10-bit V-Log is the amount of information recorded at the time for each colour channel. In 8-bit video each colour is recorded with 256 tonal levels – or shades – but in 10-bit video the number of shades per colour is 1024, which can make a big difference.
When you right-click on the pictures above to make them bigger you’ll be able to compare the Scopes section of Davinci Resolve video editing software as it displays graphics that illustrate the tonal and colour content of two V-Log clips shot in the same conditions, one in 8-bit and the other in 10-bit. On the top line you can see how the information in the clips is represented when the clip was straight out of the camera. If you look closely you’ll be able to see small gaps, or blank horizontal lines, in the information. On the lower line you can see the scopes for the same clips when graded with the contrast needed to make them look normal. You’ll notice that as the clips are stretched out to produce black and white point the gaps in the 8-bit clip widen. For this moderately contrasty scene the gaps won’t show unless further curves or tonal manipulation are needed, but the clip will need to be handled with care to avoid banding in flatter areas, such as the sky. The 10-bit clip also has some gaps but they are much smaller and will require far more abuse in post-production for any damage to be caused
The advantage of shooting 8-bit V-LogL over regular Photo Styles will only be apparent in high- or moderate-contrast conditions though, as shooting 8-bit V-Log in low contrast scenes can easily lead to banding in the final production. Low contrast scenes will produce a wave form that needs to be stretched more, and 8-bit footage has less information to stretch with, so tonal transitions will appear as steps/bands rather than a smooth gradient. In low contrast conditions we are much better off shooting with a regular Photo Style rather than an 8-bit V-Log setting. Using a normal Photo Style, such as Natural, in 8-bit will probably be better as we won’t want to do too much to it afterwards. But when we’re shooting in V-Log or V-LogL we are on a path that inevitably leads to extensive manipulation, and 8-bit footage finds that harder to cope with.
Manipulating the tones in this frame, which was recorded in the Scenery Photo Style, has pulled the tones of the 8-bit file apart too much. This is evidenced by the banding visible in the sky
Shooting V-Log in high contrast scenes might also give you a false sense of security which 8-bit won’t live up to. When we are shooting in the ‘super-safe’ V-Log we might assume we can pull back detail in highlights that are actually being recorded as pure white. So, care needs to be taken and we shouldn’t automatically assume that a Log setting will give us the best results.
Even 10-bit V-Log has it limits, as shown here. The light in the blind over the window is burnt out, but it still has a mostly natural appearance and it isn’t a distraction
Relating these bit depth differences to stills for comparison, shooting video in 8-bit is like shooting a normal JPEG file – which will also be 8-bit. Still raw files are usually 12-bit in the G series cameras and 14-bit in the S models, so 10-bit video isn’t going to give us the flexibility of a rawstill image file, but it offers something in between – and using a V-Log or V-LogL profile allows us to make the most of that.
When to use V-Log
When you have V-Log or V-LogL there is a temptation to use it every time you record a clip of video, but it pays to have a think first about whether it really is the best option. In a lot of situations a normal Photo Style might do the job just as well, and often a flat profile such as ‘Flat’ and ‘Natural’ will offer more than enough flexibility for minor tweaks in post-production. It is in challenging lighting that V-Log comes into its own and becomes essential for creating a realistic final result.
Shooting in V-Log or V-LogL does require quite a lot more work after the footage has been recorded, but it can be well worth the effort to retain details in the brightest and darkest areas of the scene. An image with well-controlled contrast will always look more realistic to the audience, but when realism isn’t your goal the greater flexibility of a V-Log file allows much more creative grading
When you shoot in V-Log or V-LogL you will have to spend extra time in software to grade your footage before it can be used, so shooting this way will always take more time and slow down your process. If you need to output a job quickly, or perhaps when you are away from home, recording in V-Log will present some extra challenges that maybe you could do without.
If you don’t have access to V-Log or V-LogL, or just don’t want to have to do the work after the shoot, there are lots of controls in-camera that will help you get a better result. Here you can see the differences between a clip shot with the Natural Photo Style and how that came out in grading, compared with one that was recorded with an adjusted Natural Photo Style. To make the Natural Photo Style better able to record all the information in this scene I used in-camera controls to reduce contrast, pull down highlights and to lift shadows, as well as to reduce colour saturation. I used the iDynamic Range on the High setting too, to help the camera capture all the tones. This produced a flatter profile which contained a wider range of the scenes tones – look at the sky, for example. This meant I was able to bring out more information in software than I could from the default Natural profile
So long as you pay attention to your white balance and to getting your exposure right at the time of shooting you might find you can get fantastic footage straight from the camera that needs no work at all in post-production. Remember that Lumix cameras offer masses of control over the way finished video and JPEG stills look, so you can use white balance tuning, iDynamic, and shadow/highlight controls to make quite extensive changes to the way footage is recorded and to protect areas of extreme tonal values before you press the record button.
I used the flexibility of the V-LogL file to enhance the ghastly colours of the launderette in the evening. The overhead light is burnt out, but it doesn’t draw too much attention from the scene. It was pretty dark in the left part of the frame, but the file contained all the information needed in the shadows and gave it up when asked
If you are shooting a project of course it makes sense to record the whole thing using the same Photo Style, so if one scene will need the dynamic range that V-Log offers it makes sense to shoot the whole production in V-Log to make it easier to match colour and contrast in the final film. The same is true if you will be shooting with multiple cameras, or models from the Lumix G series alomgside models from the S Series, or even the Panasonic Pro movie cameras, as it will be easy to make sure the footage is consistant in style across all the cameras and models from which you will need to use clips. Mixing Photo Styles when shooting in the same environment will create an inconsistent atmosphere and visually jarring transitions from one clip to the next.
An example of V-LogL shot at night with the Lumix GH5S. The light on the side of the boy’s face was very much brighter than the background, but using V-LogL allowed me to even the exposure out across the two extremes
There’s no doubt that having access to V-Log or V-LogL can make a very significant difference to the way our video footage looks. The extra dynamic range as well as exposure and colour flexibility can help us out in challenging conditions and allow us more scope for creative grading when called for. As brilliant as they are though, these Photo Styles aren’t magic and they aren’t quite as powerful as shooting in raw. However, they balance that with their convenience and general ease of use – and frankly for most of us they are as ‘raw’ as we need most of the time.
Of course they take a little more work in post-production but that all pays off when we get smooth tonal transitions, detailed highlights and shadows, as well as a more moderate contrast that is easy on the eye. If you have access to these Photo Styles in your camera they are well worth investigating so you can see for yourself the difference they can make. If you don’t have access to them take a look at your in-camera picture controls and modify one of the flatter Photo Styles to see how close to V-Log you can get.