I get asked a lot of questions about the GH4, but perhaps the most common question recently has been “What does the 4K mode on the GH4 do?”, and I finally wanted to address that here today. Throughout this post, I’m going to outline exactly what the 4K Photo mode is intended to do, and how it may open up some new possibilities for filmmakers in the future.
There has been a trend over the past few years in which stills and motion cameras have been crossing over into each others territories. We all know that the Canon 5D Mark II essentially started the DSLR revolution by offering high quality video recording in a DSLR, but more recently video cameras have been offering stills functionality to a large degree of success. Cameras like the Red Epic or Dragon that can shoot 5K/6K offer the unique ability to capture both video and stills simultaneously, which opens up many options for DPs and photographers alike.
Although most cinema cameras (including the Epic/Dragon) are technically only capturing video, the quality of that video is so high and the resolution is so substantial that stills can easily be extracted from the footage. This is why Red has named their camera system DSMC (or Digital Stills and Motion Camera) and have been pushing the stills capabilities of their cameras pretty heavily.While the concept of this initially sounded gimmicky to some, it has actually been implemented on many high end photo shoots, including cover shoots for Vogue, GQ, W, Time, Vanity Fair, and many more.
Shooting video with the intention of extracting stills opens up a very wide range of possibilities and benefits for certain types of photography. One of the most obvious and simple ways to illustrate this is by considering the fact that at best, most DSLR cameras will shoot photos at 10 frames per second in burst mode. Video on the other hand can obviously be shot at many times that rate (as is the case 24fps, 30fps, 60fps and beyond). This gives the photographer many more shots to choose from per second of shooting, which can be exceptionally helpful when shooting fast moving subjects (such as animals or other wildlife), or for capturing micro expressions in a human face that may otherwise be missed in between shots on a traditional stills camera.
Panasonic clearly understands that photography and video are converging to a certain extent, and wanted to make the most of this trend on their GH4 by adding a 4K photo mode. The idea with this feature is quite simple – to allow photographers to step into a mode on the camera that will allow them to capture the most amount of frames per second. Despite what the name might suggest, the camera does not record an image sequence or a stream of still images in 4K resolution for that matter… Rather it shoots a regular video clip that you can bring into software like Adobe Lightroom and hand pick the exact frame that you want to adjust and export.
You might be thinking – Can’t I just shoot a 4K video and pull a screen grab from that later? And the answer would of course be yes, you can do that. However, there are a number of benefits to shooting in 4K photo mode that make it preferable over simply shooting a regular 4K video and pulling screen grabs later.
Two of the biggest benefits in my opinion are the “Loop Recording” and the additional aspect ratio options. Loop Recording does exactly what you think it will do – it continuously records a video loop until you stop the recording, and will re-write over previously recorded footage once the loop has run out. The idea is that if you are trying to capture a specific moment (let’s say a bird flying across the sky), and it takes 30 minutes for that action to happen, you don’t want to have to review 30 minutes of footage just to find that one moment. Loop mode will keep deleting the extraneous footage until you tell the camera that you have what you need, and in the end it will ultimately keep your file sizes smaller and workflow simpler. What’s far more important to video shooters however, is the second feature that I touched on: Aspect ratios.
4K Photo Aspect Ratios
Unlike shooting in video mode which limits you to a 16:9 aspect ratio (or 1.85:1 in 4K cinema mode, which is nearly identical to 16:9), the 4K photo mode gives you all of the aspect ratios that you would expect of a stills camera. Specifically, it can record in: 1:1, 3:2, 4:3, and 16:9. This is a necessary feature for photographers, however it is just as beneficial for video shooters as it opens up the possibility of using anamorphic lenses.
For those of you that don’t have experience shooting anamorphic – An anamorphic lens is able to squeeze more information onto your sensor than is normally possible with a traditional spherical lens. This is essentially done by distorting the image (or squeezing it), resulting in an image like this straight off of the camera:
When the image is then de-squeezed in post, it will look completely proportionate and will have it’s own unique set of characteristics. Most notably, anamorphic lenses can create very wide aspect ratios, beautiful lens flares, and extremely shallow depth of field. This is why they have been used extensively on Hollywood level features for many years, and are still the preference of many of the world’s top DPs.
In the film days, anamorphic lenses would squeeze a widescreen image onto a regular (non-widescreen) piece of 35mm motion picture film, and then when it was projected later on, a special lens was used on the projector to de-squeeze the image. The exact same principles all still apply today, but we’re just de-squeezing the image digitally as opposed to optically.
The problem with most digital video cameras today, is that they don’t offer the correct aspect ratios needed to utilize most traditional anamorphic lenses. For instance if you were to use a 2x anamorphic lens on 35mm motion picture film, you would effectively be capturing a beautiful 2.39:1 widescreen image, which is a cinema standard to this day. However, if you were to use that same lens on a 16:9 video camera, you would wind up with an extremely wide 3.55:1 aspect ratio which is far too wide for most productions. It’s worth noting that there are anamorphic lenses specifically designed for 16:9 cameras (1.33x anamorphics for instance), however they don’t really offer the full effect of a 2x anamorphic and therefore aren’t as ideal to use. That’s why it is so amazing to have the ability to change the aspect ratio on a digital cinema camera to 4:3 or 1:1 for instance, so that various anamorphic lenses can be used much in the same way the were in the film days.
So the GH4 is now giving us the ability to not only shoot in 4K, but also to choose our aspect ratio which opens up a massive amount of flexibility with regards to lens choice. Not to mention, the overall image quality and resolution that is achievable when shooting anamorphic on the GH4 is nothing short of impressive. When you consider that the vertical resolution of 4K 16:9 footage is 2160, it’s pretty incredible that you can capture 2336 lines of resolution in 3:2, 2496 in 4:3, and a staggering 2880 in 1:1. Assuming you have the right glass to make use of the 1:1 mode, you can essentially capture an image that (when de-squeezed) will amount to 5760 x 2880, which is pretty impressive.
Unfortunately though, there is still one major drawback with regards to shooting in the 4K photo mode – The frame rates.
Currently, the only frame rates you can shoot with in 4K Photo mode are 30fps and 25fps. Essentially, the frame rate will default to 30fps if you are in NTSC mode, and 25fps if you are in PAL mode. If you select the 24.00Hz cinema mode, the menu option for 4K Photo mode is not available. This is pretty frustrating for many shooters at the moment, seeing as the vast majority of cinematographers that want to use anamorphic lenses are obviously going for the cinema look, and therefore want to shoot in 24p. Right now, the only option is to shoot at one of the other two frame rates and conform your footage in post, which will never yield results that are as strong as capturing a native 24p image.
While I am certainly not a camera engineer and wouldn’t claim to know what is or isn’t possible technologically speaking with regards to the GH4, I would say that it isn’t improbable to assume that this issue will be resolved in the future with a firmware update. Clearly the camera is capable of capturing beautiful 24p images in a variety of resolutions, so it wouldn’t be a far leap for Panasonic to introduce 24p recording as a 4K Photo option with a future firmware upgrade. Will this happen? Only time will tell, but for now at least Panasonic have raised the bar for other camera manufacturers, and this may very well prompt some of their competitors to offer similar features too.