Black Line on Photos at high Shutter

[athorat]

Got this new canon5d markiv on amazon and sometimes at high shutter speed it gives a distinct black line in between the photos. is this ok at high shutter speed assuming light not passing through? but should it not darken all the image instead of just one black strip?

shutter speed 1/1600 f7.1 iso400

https://www.flickr.com/photos/156126577@N03/39992084913/in/pool-canondslr/

shutter speed 1/300 f7.1 iso400 works fine 

https://www.flickr.com/photos/156126577@N03/46042557115/in/dateposted-public/

[Ray-uk]

Difficult to tell what's happening from the pics because it seems to be a spinning subject, can you make it do it again if you take pictures of a static subject in daylight without using flash or artificial light and then post that on here.

[TCampbell]

Out of curiosity ... what is the subject in the photo?

The black band isn’t a digital artifact ...so this does not appear to be a camera defect. 

However... due to the way the camera is designed to work at high speed, you may be seeing consequences of the camera’s “rolling shutter” mechanism.

To make sense of that, watch this video:  https://youtu.be/CmjeCchGRQo

(Note to mods:  video embedding feature has changed and now appears to be broken so I'm just inserting this link instead)

My guess is that the lighting on this subject (whatever it is) is flickering at high speed and the you’re seeing things get bright / dark / bright as the camera shutter sweeps across and you are seeing this as banding.

Similar things happen with certain types of lighting systems at arenas, etc.  To the human eye they appear to provide continuous light ... when in reality they are flickering at high speed (specifically at the cycling rate of the AC power ... here in the USA 60-cycles per second).  This means at high speeds, it’s possible to get a photo at an odd moment and you end up with some photos looking perfect and others looking light they have messed up lighting even though they were taking at the same event on the same day using the same settings.   Some Canon models have an anti-flicker mode to deal with the problem (but that feature is based on the flicker being the result of AC power cycling rate or hertz and isn’t meant to deal with things that flicker randomly.

[athorat]

Thanks for the reply guys, the subject is not moving just the angle  while shooting makes it feel like. 

This had happened previously even in my living room and dismissed but now its bothering....

If you look at this snap, its big glass sphere and has glass blown LED light inside.  which circular (moving klike motion inside)

https://www.flickr.com/photos/156126577@N03/33088114408/in/dateposted-public/

I was underneath this big glass ball and shot vertically.  

[BurnUnit]

LED lamps do flicker. Not as noticeably as fluorescent lamps but they can still cause problems for camera shutters. Digital camcorders will especially show the flickering effect if the wrong frame rate is used with LED lights.

Is the dark area in your photos always horizontal or can it also appear at different angles?

[ebiggs1]

"...you may be seeing consequences of the camera’s “rolling shutter” mechanism."

+1 

[Waddizzle]

---

@athorat wrote:

Thanks for the reply guys, the subject is not moving just the angle  while shooting makes it feel like. 

This had happened previously even in my living room and dismissed but now its bothering....

If you look at this snap, its big glass sphere and has glass blown LED light inside.  which circular (moving klike motion inside)

https://www.flickr.com/photos/156126577@N03/33088114408/in/dateposted-public/

I was underneath this big glass ball and shot vertically.  

---

If light flicker is the problem, I am pretty sure the 5D4 has “Flicker Compensation” that you can enable.  It can help with multiple light sources that are flickering in synch, but not with multiple sources that are out of synch.

[athorat]

is that a problem or is it something which is by design. 

I had seen these lines even in my lving room with different light sources...  

I have tried to enable the flicker setting and not tried to shoot the same light source yet. 

[TCampbell]

Basically your light meter on the camera is faster than your eye.  Your eye doesn't really notice the flicker.  But the camera can meter the light hundreds (thousands?) of times per-second and detect the flickering.  

Presumably the flicker is genated by the AC power hertz.  In the US, the AC power is 110 volts AC power cycling at 60 Hertz.  That means 60 times per second the voltage switches from positive to negative and back on the two wire pair.  

There are some unlikely complexities.  Power from the utility company doesn't enter your home as 110v power ... it is almost always a 220v line which is split into two 110v "phases".  This means some rooms may be on one phase and other rooms are on the other phase.  I mention this because those two havles of your power are both cycling at 60Hz... just not at precisely the same moment (they are out of phase).  I suppose it could be possible where half of a room is on one phase and another half is on a different phase so the lights don't flicker at precisely the same moment.  But I suspect that's somewhat unlikely.

The camera would not be able to compensate for both at the same time.

I would suggest reducing your shutter speed to the camera's max "flash" sync speed.  This is the fastest shutter speed at which the camera is still fast enough to completely open the first curtain so that the ENTIRE sensor is exposed before it has to close the 2nd curtain.

For some Canon cameras that's 1/250th, for others it's 1/200th, and for others it's 1/160th.  It depends on camera model.

[Ray-uk]

---

@TCampbell wrote:

There are some unlikely complexities.  Power from the utility company doesn't enter your home as 110v power ... it is almost always a 220v line which is split into two 110v "phases".  This means some rooms may be on one phase and other rooms are on the other phase.  I mention this because those two havles of your power are both cycling at 60Hz... just not at precisely the same moment (they are out of phase).  I suppose it could be possible where half of a room is on one phase and another half is on a different phase so the lights don't flicker at precisely the same moment.  But I suspect that's somewhat unlikely.

---

Does this really happen in the USA ? I live in the UK where the normal domestic supply is 240V AC, each house is supplied from a single phase even though my neighbours house could be supplied from another phase. I find it strange that 2 or more different phases could be supplied to one house.