Banding with the E-M5 and the 20/1.7: A potential work-around

Started Oct 19, 2012 | Discussions thread
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Anders W
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Banding with the E-M5 and the 20/1.7: A potential work-around
Oct 19, 2012

As most people who own this combo (E-M5 and 20/1.7) are probably aware, it tends to produce banding at really high ISOs. At the beginning of June, Olympus acknowledged the problem and said: "we are continuing to study how we can eliminate this".

http://www.dpreview.com/news/2012/06/12/Olympus-acknowledges-OM-D-E-M5-banding-with-panasonic-20mm-f1-7-lens

When firmware version 1.5 for the E-M5 was made available a couple of weeks ago, there were some tentative reports from other forum members that it might have helped reduce or even eliminate the banding (although there was no mention of anything like that in the firmware announcement). In the process of testing this for myself, I eventually found that the banding was still very much there in at least some cases. However, I also found that I could sometimes produce  shots at very high ISOs that were just as banding-free as those from other lenses.

Whether the latter was possible with earlier firmware as well is something I cannot really tell at this point. But I don't remember seeing it in the tests I did in the past and the fact that I now saw it of course prompted me to pinpoint the conditions under which the banding was there and not there.

After quite a bit of experimentation and testing over the past few days, I am now reasonably (if not perfectly) convinced that I have found at least one such condition. If you leave the camera turned off for at least an hour or two and then turn it on, the first shots are very likely to show strong banding, at least if you start shooting right away. But if you fire a few shots (five or so), the banding will gradually disappear.

The test images posted on top show a prototypical exemple. Both are shot at ISO 6400 and underexposed a couple of stops. In the first image, shot right after turning the camera on, there is very evident banding. However, the second, which was shot less than one minute later after firing four additional shots inbetween and briefly looking at them on the LCD, is about as free from banding as we can hope anything to be at such an ISO and level of exposure. I have repeated this test (turn camera off, let it rest for a while, turn it on, fire five to ten shots and see what happens) quite a few times over the last few days and the result has so far always been the same: evident banding at first but then gradually disappearing.

I should mention here that I am not really done testing what happens when the camera has merely been asleep rather than turned off by means of the switch. However, my preliminary results indicate that the banding you get on start-up is less pronounced and disappears more quickly in that case. I should also mention that, for convenience, I have kept the 20/1.7 more or less permanently mounted while performing these tests, which means that I don't really know if lens swaps at this or that stage of my testing process would have an impact on the results in one way or the other.

Of course, I can provide no guarantees whatsoever, that the work-around I have found will work the same way for other copies of the E-M5 and the 20/1.7 as it does on mine. We are in all likelihood dealing with some form of electro-magnetic interference and the components involved may well behave slightly differently in one copy of the camera or lens than another. But I certainly hope it will help at least some others and I thought, on that basis, that it was my responsibility to report what I had found.

 Anders W's gear list:Anders W's gear list
Panasonic Lumix DMC-G1 Olympus OM-D E-M5 Olympus E-M1 Panasonic Lumix G Vario 14-45mm F3.5-5.6 ASPH OIS Panasonic Lumix G Vario 7-14mm F4 ASPH +21 more
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