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Paul B Felix

LED Light Interference on A7RIII

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Hi All, 

I'm new to this forum, and am super happy to see how members are active here.  Having recently fallen in love with the A7RIII, I'm eager to learn from the community which brings up the reason for this post. 

I am seeing interference from overhead LED lights inside of my house.  There are two situations that occur when the A7RIII is near LED lights.  First, the screen and/or viewfinder will have a vertical band that is darker than the rest of the image.  This band will move from bottom to top of the screen.  It is graduated and typically takes up about a quarter of the overall screen.  The second issue I've seen is that that physical buttons will simply not respond to being pushed.  I see this most often when pushing the playback button.

Has anyone else seen these issues?  Again, I'm confident that this is isolated to inside my house when I'm near overhead LED lighting.  I actually thought this was a problem with my camera and ended up exchanging it shortly after purchase.  The same issue exists in the new camera.  Then, I thought it was a lens issue (24-70 gm) and exchanged it to find the same results. 

So, I'm confident that this is related to LED lights.  I can't reproduce this outside or anywhere else.  In fact, I couldn't reproduce this at the camera store probably because they have florescent lighting.  I recorded the behavior and showed it to the camera store.  They have never seen this issue.

Curious to hear your thoughts, 

Paul

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The banding I see is not exactly the same as Fro describes, but it is very likely related. I only see one large band covering around 25 percent of the image. The band is also more graduated than the sample images. However, I’m much closer to the led light source which might be impacting this situation. I’ll test this at various shutter speeds and without using electronic shutter to see if that makes a difference. 

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I have not experienced the problems you describe on my A7rIII but... as architect and long time photographer, I am curious to learn more about the LED lighting in your house.

For instance I have light fixtures that originally were equipped with incandescent lamps, then over the years changed to CFL fluorescent lamps and now with A-type LED retrofit lamps (variety of manufacturers). Are your fixtures manufactured LED units or retrofitted as are mine? The reason behind my inquiry is that after changing my LiftMaster garage door lamps from incandescent to LED I immediately had problems with my hand remote intermittently not working. On a guess I replaced them with another brand of LED lamp (from my local ACE Hardware) and the problem immediately disappeared. The industry standard behind these lamps is not well defined and some are prone to significant amounts of RF interference.

Bob

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Hi Bob, 

My overhead lights are not retrofits.  I did a remodel on my house in 2016 and completely replaced all of the lights out.  The new lights are nearly all recessed LED lights.  They look like what is often called "can lights" that would use a flood bulb, but they are actually LED lights.

I had the same problem you are talking about with remote that controls a audio recorder when near florescent lights.  After changing to LED lights the problem went away.  I agree; the problem appears to be related to RF interference although I'm not knowledgeable enough to nail it down much further.  The severity of the problem as it relates to the A7RIII is unexpected.  Either the LED lights in my house are terribly noisy, the camera doesn't have adequate shielding, or some combination of both must exist.

Thanks for taking the time to reply.  This is a mystery that will probably continue indefinitely.

Paul

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14 minutes ago, Paul B Felix said:

Either the LED lights in my house are terribly noisy, the camera doesn't have adequate shielding, or some combination of both must exist.

Technically speaking, it's not the responsibility of the camera to be shielded against incoming noise. Rather, it's the responsibility of the LED fixture to avoid emitting such noise. Either way, if any of those failed their respective responsibility, then you observe the issues you are having.

To track this down (i.e.: identify the real culprit), I would successively increase the distance between LED and the camera. Go outside and move away from your house until the problem disappears. Or, inside the house, see how turning the lights on or off affects the problem.

Good luck with that.

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I did pretty much exactly as you described, Chrissie.  Inside the house this problem occurs only when the LED lights are on.  If I turn the lights off, or if I move outside, then the problem goes away.  The intensity of the LED light also impacts the severity of this issue.  Full power on the dimmable lights results in the worst banding.  In the living room the ceiling is much higher, and the issue is less severe.  The evidence is pretty conclusive that the LED lights are emitting some type of RF that the camera is not designed to operate within.  It is also possible that the dimmers themselves are part of the problem. 

I'm surprised that more people have not run into this issue.  My guess is that as more spaces use LED lighting camera makers will add shielding and light makers will limit the noise they produce.

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Today we find ourselves awash in an environment of low energy electronic signal (wi-fi, bluetooth, near field, cellular, etc.) to say nothing of the subsidiary effects of the circuits controlling and powering these devices. While manufacturers generally do their best, standards are not uniform across different industries (think global market) making it more than a bit like the wild west out there.

I'm surprised that the effects brought up by Paul are not more commonly experienced. Perhaps it is happening but largely ignored due to the sporadic, variable nature  of the effect.

I agree in part that the lighting and allied industries need to pay more attention but imaging device manufacturers also have responsibility for the performance of their expensive equipment in the real world. 

My gut feeling points to the electronic dimmers, which to my experience, are notoriously sensitive to electronic mismatch. Though identifying and resolving a mismatch between controlling and controlled devices can be a challenge,  particularly when using different manufacturers.

I will now kick my soap box aside.

Still, loving my a7rIII.

 

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7 hours ago, Paul B Felix said:

I'm surprised that more people have not run into this issue.

The problem is actually a known one. And it seems to be the dimmers connected to LED lights, which are among the worst radio frequency emitters. I was surprised to read, that it's the operator's (vs.: the manufacturer's) responsibility to avoid any such emissions.

Some background on this can be found here. Their advice is basically, to stick to FCC approved, consumer grade devices and to avoid devices without FCC approval, typically from "direct overseas sources". 

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I think Sony is aware of this type of problem. For stills you can switch an anti flicker mode on ( A7Riii, page 14 of menu item 1)  I guess so far they don't have a solution for video. I also don't know if flickering of lights is the same as what causes the banding in your video. It's a phenomena I have not yet experienced, yet we have only led lights in our house, some of them dimmable. 

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I've read this thread again from the beginning. And it seems Paul is talking about two separate issues here:

  • the "banding", which he showed in his video clip
  • buttons/switches not working.

For the banding, my guess is this is related to some sort of optical interference/superimposition (english: "beat"; german: "Schwebung") between the refresh rate of the LED light and the frame rate at which the camera is recording. This should immediately go away if the camera is moved outside the visual range of the LEDs, into natural daylight.

And then there is a fair chance that the buttons/switches don't work as a result of radio frequency interference from the dimmer/led combination and the internal electronics of the camera. This would eventually go away as the distance between the "transmitter" (i.e. dimmer/led) and "receiver" (i.e. camera) is increased.

 

 

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Well said Chrissie. A more technical but still illuminating (pun intended) article on LED flicker...

https://www.archlighting.com/technology/leds-fighting-flicker_o

I ran into the banding problem while taking stills recently at a museum exhibit that employed a variety of light sources, including KED's. Using the anti-flicker mode eliminated the banding. Going forward I will pay more attention to the artificial light sources in my shooting environment.

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That article on flickering is a good read.  I guess it makes sense that the refresh rate on the camera screen is somehow at the same frequency or close to the same frequency as the LED light's refresh rate.

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Hello...in my case the banding is easily apparent due to the white background - I don't see it in other scenes that I shot immediately beforehand, but don't think the bands are due to lighting irregularity (they appear more aligned with shutter movement). Could it be some conflict between the lighting and the shutter speed?

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