In use: Panasonic Post Focus after-capture focus selection feature
As announced on Friday, Panasonic has just released new firmware that enables a post-capture 'refocusing' feature in some of its cameras that run 4K video on a Micro Four Thirds sensor. I got hold of a pre-release copy of the firmware and have been able to try it out on the Lumix DMC-GX8 body.
The new feature, which Panasonic calls Post Focus, is essentially a focus bracketing function that stacks a burst of images together into a single file and allows you to choose which focus point you prefer after the image has been taken by touching the subject on the camera's rear screen.
What makes this interesting is that the camera uses its 4K video mode to record the bracket, so it can shoot 30 frames in a second providing 30 different focus points in just one second of burst/footage. During the 'exposure' the camera scans the scene from front to back and shoots a frame to cover every focus distance required, so the depth of the scene has an influence on how long the process takes. The resultant images are grabs from 4K video footage, and come out the other end as 8MP JPEG stills.
The firmware adds a new item to the main shooting menu called Post Focus. In the menu you activate the mode and then shoot as you would normally. The new mode doesn’t use the whole area of the sensor to make the image, applying a 1.45x crop to the frame that adds apparent length to the lens in use.
When the shutter release is pressed the camera quickly scans the scene to determine the closest and furthest objects and then records a segment of 4K video while the focus passes over the pre-determined range. After a moment of processing the image is presented on the rear screen, and the user can touch the different objects in the scene to find the frame in which that object is in focus.
When an object is identified as the desired focus target, the user can magnify the view and use a scroll bar across the base of the screen to perfect the focus, with the option to use peaking for assistance. Once satisfied that the sharpest frame has been selected for that point, pressing the 'set' button will save it as an individual JPEG file on the memory card.
You can take as many frames from the footage as you like, capturing stills that show the same scene but with different objects in focus. There are 30 frames for each second of footage, so the total number of frames will be determined by how long the camera took to complete the file.
The basic idea is that focus point can be chosen after the picture is taken – much like the idea behind the Lytro cameras. That might seem a little odd to most photographers, as we tend to put focusing beforehand quite a long way up our priority list. However, the feature is aimed at more than the serious enthusiast and there are some other advantages to using this system that more advanced photographers might be interested in.
The Post Focus clip can provide a rich source of material for a focus stack, which effectively increases the depth of field in a given scene at a given aperture setting. Shooting a sequence of differently focused images at F5.6, which can then be stacked and blended, will produce a final result that has the sharpness of F5.6 but the depth of field characteristics of an aperture in the range of F32. This is one way to avoid diffraction-induced softness while retaining depth-of-field.
|Post Focus used to create a focus stacked landscape image. Panasonic Lumix DMC-GX8 and Leica DG Summilux 25/F1.4 @ ISO 200, F1.4, 1/8000sec|
The same principle can be used to maintain the defocused effect of F1.4 in the background of a portrait while the focus range across the face might be more typical of F4. By shooting a sequence at F1.4, using focus points from one eye to the other, the background can be kept extremely unsharp, while the face is all perfectly in focus. This gives something of the effect of a swing movement in a technical camera or with a tilt and shift lens.
|Composite of 7 frames blended. Panasonic Lumix DMC-GX8 and Leica DG Summilux 25/F1.4 @ ISO 200, F1.4, 1/2500sec|
The benefit of using the Panasonic system for both of these techniques is that multiple images can be collected in a very short space of time, and a tripod isn't needed, unless your hands are very unsteady. The images are collected automatically and all that's required is to review the clip to extract the images you want to work with. The user can specify aperture, ISO, filter effects, picture modes, exposure modes and aspect ratio in Post Focus mode.
The disadvantage is that the final image will never be more than eight megapixels. The image bursts are saved on the card as an MP4 file, so the clips can be played in movie software and the stills extracted in Lightroom if you find it too hard to view the camera's rear screen.
The Post Focus process is designed to be used with scenes that are primarily static, a fairly severe limitation that Lytro cameras do not have. A person walking across the frame will possibly never be in focus, and panning the camera during the exposure just doesn’t work. When the camera records it needs to be looking at the same content it looked at when it did the pre-exposure scan. You can have running water from a fountain, for example, as the stream of water doesn’t move, but anything shifting about in the frame upsets the apple cart.
This is a pretty impressive piece of technology, and it certainly does exactly what Panasonic says it will. But in reality, Panasonic is one of the least in need of a don’t-miss-the-subject focus bracketing feature, as it already offers a highly accurate autofocus system with very capable AF tracking. The Micro Four Thirds format also tends to have more forgiving depth-of-field than larger sensor cameras.
The feature is certainly very easy to use, and although it takes a good deal more time than a standard single frame, it also delivers a lot more options. It is also a lot of fun to use, amazing to see in action, and I think that there are plenty of people who will get value from its use. The attention Lytro cameras got clearly demonstrated the interest in this kind of feature, but in the Lumix cameras the images are bigger and easier to view – and the bodies also function as normal high resolution cameras. On the other hand, light field cameras offer benefits far beyond simply Post Focus, like reducing depth-of-field, directly selecting depth-of-field via a virtual aperture control, and depth-based image editing. And, of course, the ability to shoot non-static scenes.
It is true that many of us are keen to have pictures with more than 8MP in them, but on holiday and snapshot occasions eight is often more than we really need. For occasions that require larger images we’ll just have to wait for the arrival of 8K Raw video in this camera line. I'm not sure that the Post Focus feature will be something people buy Lumix cameras especially to get, but alongside the 4K Photo 30fps stills mode, it is another clever side benefit of having high resolution video.
|Waffles with fruits by Coolinarka|
from Food photography (desserts)
|Vestrahorn Frozen Reflection by Will B Milner|
from Ice cold
As summer really gets going over here in the Northern hemisphere, the team at Imaging Resource has put together a list of the best cameras for backpacking.
The Ukrainian Parliament banned statues of Lenin in 2015. Two years later, the monuments no longer adorn public buildings or stand watch over town squares, but they're still there.
If you had to choose one camera to bring along for the ultimate West coast road trip, what would it be? DPR's Sam Spencer choose the X100F. Read more
The a9 boasts impressive capability. As more examples of it in practice pour in, Sony's claims hold up. Watch the a9 track and maintain focus on a rapidly approaching basketball.
Last week, more than a million tonnes of Californian coastline slid into the ocean, taking part of Highway 1 with it. Check out the remodeling in photos taken before and after the landslide.
Even after eighteen months of reviewing the latest, greatest, shiniest and must-buy-me-est new gear, DPReview staffer Carey Rose has continued to use older DSLR cameras for his freelance work. But now, that might be changing. Read more
Sony is the world's leading mirrorless camera brand but remains third for ILCs overall, it's said in a presentation to investors. A focus on high value cameras and lenses should boost operating income, it says. Read more
It's nicknamed the 'Cycloptic Mustard Monster,' and is a 3D printed medium format camera. Read more
The new NanGuang LED lights are battery powered and come with accessories including filters and diffusers.
Have you been telling yourself, "Hey, I really need one of those 8K displays?" A video about Dell's new 8K monitor shows you what to expect. Is it really that much better?
Tamara Lackey, a Nikon ambassador USA and pro shooter, discusses embracing self-consciousness as a means of connecting with subjects.
There's a new Spiderman movie coming out and the poster been generating a lot of online chatter. Mostly about how it looks like the creation of a fevered teenager that just discovered Photoshop.
An honest defense of the system's merits, with photos as proof.
Copyright disputes are no fun at all. 'Binded' is a new startup that aims to simplify the process of registering - and enforcing - copyright for photographers. Read more
Not everyone wants to pay a premium for a long zoom camera. Thankfully, there are many reasonably priced cameras available, though they won't offer the same image quality as enthusiast models. In this updated roundup we look at big zoom cameras with more consumer-friendly price tags. Read more
Think Tank Photo has updated two of its popular bag lines with improvements to functionality. Read more
We’ve all seen Bob Jackson’s Pulitzer Prize winning photo, but there's another.
The sample footage looks good.
It will automatically pick the best camera settings depending on shooting conditions. It even promises enhanced functionality for your camera, like exposure and focus stacking. It already supports many cameras from Canon, Fuji, Nikon and Sony. Read more
As if $13,950 wasn’t enough to pay for a special edition lens, the Leica Store in San Francisco is offering a prototype of said lens for $24,995. Read more
Make those old photos disappear without deleting them forever.
Firmware updates enable 10 fps shooting with adapted A-mount lenses, and faster startup times and better compatibility for 20 fps shooting when using native lenses on the a9.
Fujifilm has released firmware updates for its camera models X-T2, X-Pro2, GFX 50s, X-T20, X100F and X-T1 and updates to three of its software products.
A 22 year-old Romanian photographer uses his DJI Phantom 4 drone to capture unique perspectives of the city where he now lives.
What's it like to ride the waves with champion surfer Kelly Slater? This VR video from Teton Gravity Research gives you a taste.
When Nikon released the full-frame D3 in 2007, it changed the professional photography industry. In this week's Throwback Thursday, Barney remembers a legend. Read more
The new stuff should have better red hues, improved sensitivity and finer grain - but don't worry - will still shift blues to green, greens to purple and yellows to pink.
Ricoh has introduced a new rugged compact camera with a 16MP CMOS sensor, 28-140mm lens, 2.7" LCD and built-in LED macro lights. Read more
This compact drone can shoot HD video using a 2-axis stabilized 12MP camera. Read more
The new Prynt Pocket can print a photo directly from their iPhone simply by inserting the phone into the printer, then snapping a photo. Each print will cost about 50 cents. Read more