In this article we will look at what AF technologies Olympus build into the E-M5 and how we can use those technologies to better focus with the E-M5. Their has been many great images placed on the web showcasing the new E-M5 camera’s, excellent image quality. A few reports of slightly blurred images from E-M5 owners also surfaced on the web. It is those blurred images and why it happens, I like to address in this short article.
This article on Single Auto Focus (S-AF) will not apply to each E-M5 owner, but will be of value to a large sample I believe. The reason simply is, those who use their cameras as close as possible to its default settings or on IAUTO will have less questions on auto focus. Those who configure their cameras for specific tasks or behavior will have the highest risk of doing something that might result in camera behavior that will lead to questions. Therefor please keep in mind that this article does not try to fix a general problem, instead a really small sample of users could be experiencing probems with AF.
To better appreciate the E-M5’s Auto Focus technologies we need to take a step back and look what these inherent technologies are that Olympus built into the E-M5 and the Olympus MFT lenses. Starting with the kit lens of the E-PL2, Olympus implemented a new technology MSC (Movie & Still Compatible) that would provide quieter lens operation during video recording plus that would integrate with future Olympus MFT camera bodies, faster AF operation. Olympus claimed that the PEN 3 range including the E-M5, has the quickest AF performance of all cameras available today.
Olympus developed a new Auto Focus technology build into its new generation MFT camera bodies called FAST AF. You welcome to go research more about these new technologies (FAST plus MSC) yourself. For purposes of this article I like to quote the following interesting numbers. The E-M5 scans the full sensor during a typical AF cycle at 240Hz, twice as fast as the GH2 does. The E-M5 uses contrast AF technology and studying several Olympus papers I were surprised to see how many advantages the new FAST AF technology offer compared to the more traditional Phase Detect AF technology found in SLR cameras. It offers better 3D tracking abilities, faster and more accurate auto focussing plus improved low light auto focussing. These are only a few of the advantages listed.
Important for us users are the fact that these new technologies really give us a benefit when we use the body and the lens together as one system. At this stage it is only Olympus MFT lenses that offer the right technologies to link properly with that build into the Olympus MFT bodies. Olympus did not design the new FAST AF technology in its recent M43 camera bodies in isolation, they also looked at the lens. For example Olympus claim in different E-M5 launch papers that the new 12 - 50 mm MFT lens design is an integrated part of the E-M5 “FAST” auto focus system.
Naturally the question will be, why do we not all see the benefits from these new technologies? Why is it that some get more than expected, blurred images?
Photographers also unconsciously transfer old style SLR habits to the new PEN 3 and E-M5 cameras. Typically photographers force the camera to use a single AF Frame and they then positioned that single AF Frame in the center of the image view, just like they would do with an SLR style camera. Photographers then generally use the E-M5 AF frame like a traditional SLR center type AF indicator. In the process Photographers regard the 3x3 AF frames or the 35 frames options as beginner style options.
The new 35 AF Frame option or the 3x3 AF Frame option, functions different to what we use to on compact cameras. It basically works like a single AF Frame option that was placed in the center of the image view and it will automatically select a new AF target the moment the E-M5 struggle to focus onto the center AF frame. With the next image the camera will automatically default back to the center AF frame.
I often see people posting results like the above image on the web and then ask for support to improve the sharpness of the E-M5. Personally I also experienced similar poor image results. Why is it that photographers get results like this with an advanced product like the E-M5? At times I myself blamed the E-M5 body, at other times the 12 - 50 mm lens and after spending much time on the web I even started doubting the Image Stabilization (IBIS) plus the so called “resonating” shutter of the E-M5. Knowing and adapting my own style I still did not get good results on a regular basis. I started taking literary hundreds of test images using different bodies, lenses, trip-pod or hand hold and again on and on the list goes.
As with all problem solving situations the final results or solution is always amazingly short and simple and in this case it is no different. The secret was to study the Olympus available information, to work at understanding how the new technologies Olympus developed really help us plus to work hard at using the camera the way it was designed and intended to be used, by the manufacturer. In the next few paragraphs I will explain how I believe the E-M5 was intended to be used and how that then support us photographers get the most from the E-M5.
In the above image you can see what happens with many images today. Images typically have different levels of depth, objects closest to the camera, objects in the center of the field of view and objects right at the back. With SLR cameras this was never much of an issue because the cross type autofocus indicator in the view finder was much smaller than the relatively large AF Frame of the E-M5. I inserted a smaller black and white crop of the above image at the bottom right corner of the image. The insert shows how the E-M5 AF frame in green, cover several focus distances, the swing, the grass and the autumn leave. On which of these three object distances will the AF frame focus? Well, in this example not one of the objects in the frame were well in focus or sharp.
Keep in mind that the E-M5 scans the frame or complete sensor at 240 times (240Hz) each second when the shutter is pressed halfway. During each individual scan the camera typically take hundreds of samples and measurements. Lets look at a possible example of what could happen when the user press the shutter button halfway. Keep in mind this example take into account we force the E-M5 into a SLR type style.
After the first few milliseconds, scans the camera identified the good and the bad focus points in the scene and most probably already determined what it could do to optimize the image focus (DOF) for that scene. During the following scans the E-M5 will try to implement the best focussing plan for the scene. The user preferred AF target could end up not being an optimum focus point for the camera, especially for those who limit the E-M5 to one only center placed AF frame,
Based on what I learned, my camera will be configured for a new AF plan in the future. First I will configure my E-M5 for the 3 x 3 Af frames option. In fact the users manual suggest the full 35 AF frame option for day to day use and the 3x3 option for moving subjects. Even when configured for 35 AF frames, you will see the camera prefer to use the center AF frame. It is only when the camera cannot find a good AF contrast point at the center position that it will select or propose another better suited AF frame in the lens view. It is when you select the 35 frame option that the camera can quickly select or suggest an alternative point. It will even select that alternative point on a similar distance as the original point away from the camera. The better placed AF frame only means the camera will be able to find a better more accurate final AF measurement when the shutter is pressed down all the way.
If you not happy with the “better” placed AF point you can release the shutter button and you can start over by turning the camera to a new and similar distanced object in the image, then place the “Auto” center AF frame over the new object and then press the shutter half way to lock the AF distance, once receiving the OK signal the photographer can turn back keeping the shutter pressed halfway and then reframe the image. If you now take the image by pressing the shutter all the way, the E-M5 will use the locked AF data. (As also explained in the users manual)
One important function probably most of us “experts” needs to learn to work with is face recognition. Personally I do not have face recognition switched “ON” all the time, I will select that on the SCP (Super Control Panel) as I require. When using the multiple 35 AF frame setup it is important to let the camera do the focussing on portrait work for us. Is that incorrect? No, it is only a different style to SLR photography and something we can get use to plus improve our style on and master. The last thing any photographer want is to have a large AF frame covering several distances to the sensor when targeting the person’s eye!!
One more important point when working with the E-M5 is to develop a style of pressing the shutter halfway, to wait and to receive the focus OK signal from the camera and then to press the shutter all the way. It is only in really high speed situations that one will frame and press the shutter all the way in one smooth go. Landscape photographs will always benefit most from pressing halfway, wait for the OK signal, do the final framing and then to press the shutter all the way. To see where I focussed in the scene, I could not find the AF frame to show in Olympus Viewer software, I did managed to see it in the “histogram” type image preview on the E-M5. This will help you confirm exactly at what point in the image was the camera focussed on.
If I am still not happy with the results after refocussing, locking and reframing as in the above example, the E-M5 makes it possible to step up the auto focus accuracy one more step. In a different article I explain how to use the Zoom AF frame option. Also see the basic set-up article I wrote. These articles will give you more information on setting up your E-M5. (Please always check the last update date to ensure you see the latest version of the article) The next step in finding an accurate AF cycle, is selecting the “Zoom AF Frame” option by pressing the right button on the camera. As you do that, you will see the shape of the AF frame change plus it will be much smaller in the view finder when it is set to 14x zoom. You can go ahead and focus with that smaller sized Zoom AF Frame. Generally the Zoom AF Frame scan the focus point a little different to the standard AF frame and the results are general quick and accurate. The E-M5 will position the Zoom AF Frame on the last used 35 AF frame position, typically the canter point.
The E-M5 offer one more option to find a precise focus point and good sharpness if the previous two options failed. The third option is to physically zoom into the Zoom AF Frame by pressing the function button that activate the zoom function, a 2nd time. The Zoom AF Frame area, as shown in the insert, will then fill the complete E-M5 camera screen. The zoom frame will deliver the most accurate results. Keep in mind that both the Zoom AF Frame or the next level zoomed in view, will use a different type AF scan to lock the focus distance.
Some people complain that the E-M5 does not stay in the Zoom AF Frame mode when the E-M5 was switched off and then on again. Again that is fundamentally wrong to try and force the E-M5 to function like an old style SLR camera with the smaller style Zoom AF Frame. Let the E-M5 default back to the multi (35) AF frame selection. As you will master the new style in the future and as you get use to the different styles of focussing with the E-M5, users will find it difficult to go back using an old type style SLR camera again. I know of no SLR that will give you the Zoom AF frame on the fly as the E-M5 does, get use to that and enjoy the new way of working with a camera.
The above image was taken using the Zoom AF Frame function. Switching over to the Zoom AF Frame function completely changed the behavior of the camera, it was easier to lock onto the exact point I wanted to focus on plus the control I had, moving the focus point was great. Does it slow down the camera? Not really, it is only in really special cases which I will switch over to the Zoom AF Frame, keep in mind that for day to day use I started trusting the E-M5 in the 35 AF frame mode.
I decided to add this last paragraph, to close the article with a 8 line summary:
The E-M5 has the possibility to let the user assign functions to camera buttons as the user find best for his or hers own style. In my article on basic set-up for the E-M5 I discuss how to assign unique functions to specific buttons on the E-M5
In this article I propose the user to assign the so called Zoom AF Frame function to a button on the E-M5 - see P45 in the users manual or see this article
Finally my advice is to select the 3 x 3 AF frame (default) mode for the E-M5 - again in the basic set-up article on this site I discuss how to select an AF mode. The user could decide to keep face recognition active all the time or to activate and de-activate it via the SCP (Super Control Panel)
The camera is now ready to be used as I described and suggested in this article.
During normal operation nothing will change, use the camera as normal for most users. For those who tried to use the E-M5 in what I refer to as the old type SLR style, my advice is to give the 3 x 3 AF frame mode a chance. It is really good plus Olympus did a great job to fit two worlds into one (SLR world plus 35AF frame world into one)
For more accurate focussing, press the programmed button on the camera to display the changed shaped AF Zoom Frame - on my E-M5 I adjusted this frame to 14 times zoom. Point the AF frame to your target, press the shutter halfway to auto focus (AF), do your final framing of the image while holding the shutter halfway and take the image by pressing the shutter all the way.
One final option is to select a precise focus point is the following. High levels of focus point selection accuracy is possible using this method. Press the programmed button a second time and the E-M5 will zoom right into the Zoom AF Frame showing the content of the AF frame on the camera screen. Now the user can go ahead and select that point in the image to focus on as the user wish too.
When the image is taken press the programed button again and the E-M5 will go back to the standard Zoom AF Frame view, not the “zoomed-in” view, to see the standard AF frame again, press and keep the programmed button just that half a second longer.
That is it, now you will be able to practice a new and extremely powerful new way of using your E-M5