Sport / Action with Micro 4/3 Cameras
Author AndrewS August 2012
Introduction Most mirrorless interchangeable lens cameras (ILC) including all Micro Four Thirds cameras to date use Contrast Detect (CD) autofocus technology. DSLR's in viewfinder mode use Phase Detect (PD) autofocus. Canon EOS-M, Nikon 1 (and soon Sony NEX) ILC's use both phase detect and contrast detect AF technology. Until recently it has generally been the case that PD systems were best for following focus on moving subjects while CD systems were more accurate with still subjects.
M4/3 and sport/action I wanted to find out if current model M4/3 cameras could be useful for sport/action photography. For the tests I used two camera bodies, Panasonic GH2 and Olympus EM5, both hand held for all shots, viewing through the EVF. Lenses used were Panasonic 100-300 mm and Olympus 75-300 mm, mostly at the long end. For the follow focus tests I made hundreds of photos of three subject types, (1) Motor vehicles driving steadily towards and away from the camera at about 60 Kph, (2) Board riders catching waves, (3) Junior soccer.
Note on M4/3 "Focus Tracking" Focus Tracking refers to a technology by which the camera establishes focus on a particular part of the subject which is then tracked and held in focus even when framing alters. I set focus tracking OFF with the EM5. You can find this in Custom Menu A >AF/MF >AF Mode > C-AF, not [C-AF+TR].
With the GH2, I set the Auto Focus Mode Dial to [1 area focusing], Not [AF Tracking].
Several published reviews of the EM5 have commented adversely about it's "Focus Tracking" performance. The capability we are really looking for here is "Follow Focus" which is not the same thing as focus tracking at all. I would guess that some of those adverse review findings may have been the result of setting focus tracking ON . This forces the camera to make extra calculations on every frame, thus slowing it down.
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| High Jump Prefocussed manually on the bar |
Sport/Action technique With respect to focussing there are two separate and distinct approaches to sport/action. The first approach is to prefocus manually on a selected location and wait for the action to reach that spot. This strategy long predated autofocus and is still very useful in many situations. Any camera capable of manual focus can be used. M4/3 is very suitable due to the accuracy of manual focus with MF assist.
The second approach is to engage continuous autofocus (Oly C-AF, Pana AFC) and Sequential (Oly) or Burst Mode (Pana) Drive, then hope the camera can follow focus on the moving subject. The remainder of this article is about follow focus tests and results.
Camera Settings Below are the settings I used for all the tests. The GH2 has several set and see dials and user assignable function buttons so can be set up for action using the hard control modules directly. I find the best way to set up the EM5 is to register a Myset once all the settings are in place.
*Mode Dial >S, shutter speed 1/800s - 1/1000s
*Autofocus: Panasonic>Focus Mode Lever > AFC, Auto Focus Mode Dial >1 Area Focussing. Olympus>C-AF (not C-AF +TR)
*Drive Mode: Panasonic >Rec Menu >BurstRate >M (nominally 3 fps). Olympus >Custom Menu C >Sequential >L, 3.5 fps and, note carefully >Sequential +IS OFF >OFF This double negative is a bit of Olympus obfuscation without which the menu would be easier to comprehend. Anyway set this item to OFF to make IBIS ON with Sequential drive.
If you set the Burst/Sequential rates any higher the cameras will not be able to provide CAF, IS and EVF preview on each shot.
*Image Quality> JPG Large/Fine (not super fine)
*Image Stabiliser ON. I used Panasonic IS1, Olympus IS1.
*Auto ISO
*AF area. I used single area, center position. Standard size (green square) on the EM5 and second up from the lowest size on the GH2.
*Memory Card: SDHC SanDisk Extreme Pro 95 MB/sec.
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| Cars at 60 kph Frame 1 of 11 EM5 Oly 75-300 CAF |
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| Cars at 60 kph Frame 9 of 11 All frames between 1 and 9 were sharp |
Setup notes
*It is important to avoid anything which will slow the camera down, for instance a slow memory card, Focus Tracking, RAW capture or copyright data on the EM5.
*Focus Priority vs Release priority. Both cameras allow you to nominate focus or release priority. For the GH2 this is in Custom Menu >Page 2 > Focus priority on/off. Presumably Panasonic focus Priority off is equivalent to Olympus Release Priority on. With the Olympus it is in Custom menu C >Release > Rls priority S(ingle) or Rls Priority C(ontinuous). I was not sure what to set so I did the tests with Focus priority on for the GH2 and for the Olympus [Rls Prio S] >off and [Rls Prio C] >on.
*Image Review. Auto Review, found in Setup Menu >Page 2, is automatically greyed out with the GH2 in burst mode. For the EM5 I set Rec View >off in the setup menu.
*EM5 EVF frame rate. I set this to High in Custom Menu J. The instructions say "Set high to reduce display lag".
*EM5 Vivid Picture Mode. There is a view circulating on user forums that C-AF works best with Vivid Picture Mode set. This may be so but I forgot about it while testing so had picture mode on the default and never got to test the effect of Vivid setting.
*Readers please note, if you are unable to reproduce the follow focus results reported here, go through your Menu settings/button functions/SCP/QMenu settings with meticulous care, item by item. You may have inadvertently set some item which interferes with the follow focus process.
Burst Rate With the settings above and the shutter held down the following actual burst rates were recorded by stop watch using 20 frames per burst:
GH2 with Pana 100-300mm lens: 2.2 frames per second.
GH2 with Oly 75-300mm lens: 2.5 frames per second.
EM5 with Oly 75-300mm lens: 3.5 frames per second.
EM5 with Pana100-300mm lens: 2.3 frames per second.
I noted the shutter cadence was quite lens dependent.
With the Oly 75-300mm lens the EM5 went ...chup-a-chup-a.....(double sound)
Both cameras +Pana100-300mm lens went ......click-a-da-click-a-da....(triple sound)
There is some characteristic, I know not what, about the Pana100-300mm lens which slows both cameras down and produces a different shutter cadence.
Overall the Oly 75-300mm lens on the EM5 body had the best burst rate.
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| Cropped frame GH2 Pana100-300 AFC |
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| Cropped frame GH2 Pana 100-300 AFC |
Results, detail I made many sequences of shots in each setting and rated each frame as [Sharply in focus] or [Almost, but not quite sharp] or [Out of focus].
Cars driving towards and away, bright sun on subject
GH2 with Pana100-300: Sharp 21%, Almost 75%, Out 7%
EM5 with Oly 75-300: Sharp 58%, Almost 28%, Out 11%
Surfboard riders, some cloudy, some bright sun
GH2 with Pana100-300: Sharp 40%, Almost 51%, Out 8%
EM5 with Oly 75-300: Sharp 60%, Almost 38%, Out 2%
Junior soccer, Dull day, rain threatening
I only tried the EM5 + 75-300 as it performed best in the previous tests. I made 205 shots of which 5 were sharp (2.4%) and 50 Almost (24%). The rest were out of focus.
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| Dull day EM5 Oly 75-300 CAF |
Results, summary Clearly the EM5 with Oly 75-300mm lens gave the best results. I was quite surprised to see how well the Olympus held focus on motor vehicles at 60 kph. I made many sequences of 9-11 frames in which all but the last one or two were sharply in focus. I used no special technique at all, simply stood by the roadside, hand held the camera, centered the radiator grille in the frame, half pressed the shutter release button for about half a second to allow the camera to acquire focus then fully pressed the shutter release button and held it down until the vehicle filled the frame or more. The surfboard riders were more distant and much less predictable in lateral movement but quite steady in their speed of approach to the camera. Junior soccer on a dull day was by far the most difficult test. There were constant changes of speed and direction with players running in and out of the frame all the time. No surprise I got few keepers that day.
Conclusion Some ILC's still lack any useful follow focus capability but M4/3 is starting to close the gap between ILC's and DSLR's, while continuing to provide more consistently accurate single shot AF. The Olympus EM5 plus Olympus 75-300mm lens can be used for sport/action photography with the reasonable expectation of a useful percentage of in focus frames. Results are best with subjects in direct sunlight travelling at a steady speed towards or away from the camera.
