topic Re: 5D Mark III Horizontal Banding in stills? in EOS DSLR & Mirrorless Cameras

5D Mark III Horizontal Banding in stills?

chase — Sat, 23 Apr 2016 16:09:03 GMT

Does anybody know how to fix this problem, or even know if it's a sensor or lens problem? I was shooting a show last night and noticed these stripes about halfway through. I was shooting at 4000 ISO, 1/1600 and the stripes were extremely prominent, so I thought it was the shutter speed. I slowed down to 1/640 and got the same result. I was also using a 70-200L IS II USM. The first image was at 1/1600.. The second image was at 1/1000, and the third image was at 1/640. Any help is greatly appreciated.

Re: 5D Mark III Horizontal Banding in stills?

RobertTheFat — Sat, 23 Apr 2016 16:32:00 GMT

I believe the shutter on a 5D3 moves vertically, and at those speeds it moves as a slit, with the closing curtain trailing the opening curtain by less than the height of the frame. If the concert was using high-speed strobe lights of different colors, you'd see a band of whatever color light fired when the slit was in position to record it.

Re: 5D Mark III Horizontal Banding in stills?

chase — Sat, 23 Apr 2016 16:35:05 GMT

Thanks, any tips to avoid this? And it's not a camera problem?

Re: 5D Mark III Horizontal Banding in stills?

kvbarkley — Sat, 23 Apr 2016 16:40:01 GMT

Lower the shutter speed to the maximum flash sync speed which is basically the same problem.

My T6S has flicker prevention, if your camera has it, you might try that, too. Though it is geared for 50/60 Hz flicker.

Re: 5D Mark III Horizontal Banding in stills?

chase — Sat, 23 Apr 2016 16:43:14 GMT

That's only 1/200, and shooting a concert just won't do for that. I had no problem shooting a show at the house of blues about a month ago using higher shutter speeds and I assume they are using the same lights. I thought maybe it was a sensor damage problem, or a lens problem.

Re: 5D Mark III Horizontal Banding in stills?

RobertTheFat — Sat, 23 Apr 2016 16:43:31 GMT

@chase wrote:
Thanks, any tips to avoid this? And it's not a camera problem?

Well, it's a camera problem in that it's a consequence of the way a focal plane shutter works. You can minimize the effect by using a slower shutter speed; but if the color of the ambient light is changing rapidly relative to the speed that the shutter curtains travel, there can still be a difference in color between the top and bottom of the frame.

Re: 5D Mark III Horizontal Banding in stills?

chase — Sat, 23 Apr 2016 16:46:49 GMT

That makes sense if it's just a gradient color difference from top to bottom, but the fact that there's bands in between, makes me think something different. Color, black, color black. I don't think the strobes were changing that rapidly.

Re: 5D Mark III Horizontal Banding in stills?

RobertTheFat — Sat, 23 Apr 2016 16:58:05 GMT

@chase wrote:
That makes sense if it's just a gradient color difference from top to bottom, but the fact that there's bands in between, makes me think something different. Color, black, color black. I don't think the strobes were changing that rapidly.

It's not just the rapidity of change; it's also the duration of the flash, which can easily be 1/1000 second or less. You may not notice how fast it is, because of the relatively slow recycle time of the human eye, but the camera notices. If the shutter slit reaches a given position and no light fires while it's there, you'll see a black bar.

Re: 5D Mark III Horizontal Banding in stills?

chase — Sat, 23 Apr 2016 16:59:49 GMT

Thanks so much! Still a little difficult to grasp my head around, but I'll make do. Thanks again.

Re: 5D Mark III Horizontal Banding in stills?

ebiggs1 — Sat, 23 Apr 2016 21:40:40 GMT

I'm more convinced that these are good old fashioned JPG artifacts. Stick with as little compression as possible. Shoot in RAW don't use jpg and definitely not in anything less than a large jpg. Also stick with sRGB color space.

I really doubt it is your choice of SS causing it.

Re: 5D Mark III Horizontal Banding in stills?

Waddizzle — Sat, 23 Apr 2016 23:28:50 GMT

@RobertTheFat wrote:
I believe the shutter on a 5D3 moves vertically, and at those speeds it moves as a slit, with the closing curtain trailing the opening curtain by less than the height of the frame. If the concert was using high-speed strobe lights of different colors, you'd see a band of whatever color light fired when the slit was in position to record it.

I am inclined to agree with Bob's gut instincts. Solid state lighting sources do not emit light at a continous frequency. Instead, they emit light strobocopically, meaning the fixture will quickly flash different colors, to achieve an average that the human eye will see as a constant color. For example, an LED can quickly strobe between red and green to yield what the eye percieves as yellow. Unfortunately, digital DSLRs do not allow themselves to be as easily fooled as the human brain.

Re: 5D Mark III Horizontal Banding in stills?

chase — Sun, 24 Apr 2016 02:30:15 GMT

So I should just not shoot at high shutter speeds? I went as low as 1/640 but even then I still got the bars.

Re: 5D Mark III Horizontal Banding in stills?

RobertTheFat — Sun, 24 Apr 2016 06:10:06 GMT

@chase wrote:
So I should just not shoot at high shutter speeds? I went as low as 1/640 but even then I still got the bars.

If the light that illuminates the scene is absolutely constant, you can use any speed you like. If it isn't, you risk getting artifacts at any speed at which the second shutter curtain begins to close before the first curtain finishes opening. (That's also the maximum speed at which you can use flash, because the flash can't illuminate the full scene unless it fires with the shutter fully open.) On a 60D that's probably around 1/200 second. If the ambient illumination consists of discrete flashes of different colored light (a common situation at rock concerts), the artifacts are likely to take the form of colored bars perpendicular to the direction of travel of the shutter curtains.

Think of it this way: At shutter speeds higher than 1/200 second, the two shutter curtains form a slit that travels across the focal plane. For every position of the slit, the camera's sensor will see only the lights that flash while the sensor is in that position. If flashes of red light dominate, you'll see a red bar, etc. The higher the shutter speed, the narrower the slit will be, resulting in narrower, more clearly defined bars. Depending on the frequency of the flashes, the color is apt to be purer too, since the sensor will see fewer flashes for a given position of the slit. Note that if no lights flash while the slit is in a given position, the bar will be black.

The foregoing description is a bit of an oversimplification, since the light is constantly changing color and the slit is constantly changing its position. But the probability that the various effects will cancel each other out is very low. So if you can't tolerate the artifacts, you're left with two choices: provide your own light source (e.g., flash) or use a shutter speed of 1/200 second or less. In a live concert situation, the slower shutter speed may be the only practical option.

Re: 5D Mark III Horizontal Banding in stills?

ebiggs1 — Sun, 24 Apr 2016 13:25:28 GMT

"So I should just not shoot at high shutter speeds? I went as low as 1/640 but even then I still got the bars."

A simple test. Slow your SS to an unreasonable setting, maybe 1/30 and try. Don't worry about the actual photo. Also try another at 1/1000 or higher. What do you see? I think you will find out SS is not the issue. Shoot these tests in RAW.