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2 EOS Camera Failures Inside a church??


Question: Can something being transmitted inside a room affect EOS cameras? 


Last Saturday while shooting a wedding I had a 5D and an EOS R seemingly record perfectly. 

When I got home only the clips that were shot inside the church were corrupt files. 

BOTH cameras have corrupt video files from the ceremony. ALL the rest of the files from the entire day from both cameras are perfect. Filmed from 1pm to 11pm. 
104 clips from the 5D that day, only 2 ceremony files corrupt.
360 clips from the EOS R that day, only 2 ceremony files corrupt.
- 15 mins of a 21 min clip plays fine, then freezes
- 7 mins of the following 9 min clip plays, then freezes
- 1:14 of a 21 minute clip on the other cam plays then freezes
- 3:39 of the following 8 minute clip plays then freezes
There's no explanation I can think of.
Has anyone ever had this?
Two different camera models, on tripods, not plugged into anything - is it possible something was being transmitted in the church that affected those clips??
I know that sounds crazy, I mean, I've done over 500 weddings and never seen anything like that. Audio/video transmission wouldn't affect a camera, right? They weren't live-streaming but if they were that wouldn't affect my cameras either.
I'm just at a total loss for what happened and need to be sure it doesn't happen at my next wedding.
I had a third 5DmkIV with a wide shot setup and it was recording to a CF card and it was fine. The other two cameras were writing to SD cards: 128GB SanDisk Extreme Pro 170 MB/s cards.
The common denominator with the issue is 1. the SD cards, 2. being inside the church. Outside the church every single clip is perfect. We didn't operate the cameras any differently on those two clips than any other time of the day though.
I know I can't recover the files at this point. Putting the card back in the cameras says "cannot playback file" on screen. Plus, the one clip is only 287MB which is nowhere near the size that 21 mins should be. So it showed "recording" on screen, and when I tap it in Finder it shows 21:01, but only plays 1:14.
If anyone has theories or ideas I'd really appreciate it. 
Today I  filmed over 21 mins on the same camera/same card at home and it worked perfectly. So why did a 21 min clip inside the church fail?


Electronic devices generate and are also subject to interference generated by other devices.  It is quite possible that there is an electronic device in the church that is generated enough RF (radio frequency) garbage that it is causing other electronics to have issues but if so it is an extremely strong field.


In the U.S., the FCC (Federal Communications Commission) is the primary regulatory body HOWEVER enforcement is extremely weak and many devices are imported which in no way come close to complying with Part 15 of the FCC standards:


Other than RF interference to your camera, I can't think of anything in the church that would cause a camera glitch of this type.  To be clear, although your camera isn't a radio-like most modern electronics it is a combination of analog and digital electronics with components operating at very high switching/processing rates and these actions both generate RF energy and make the device subject to interference from other RF energy.



EOS 1DX M3, 1DX M2, 1DX, 5DS R, M6 Mark II, 1D M2, EOS 650 (film), many lenses, XF400 video

Hey thanks so much, I appreciate your thoughts and that's what I was wondering.

I'll contact the church and see if I can talk with their technical director because this could happen again to another person. 

Thanks again!! 

You are welcome!


I think RF interference and demonic possession are the only two possibilities and I am betting on the former 🙂



EOS 1DX M3, 1DX M2, 1DX, 5DS R, M6 Mark II, 1D M2, EOS 650 (film), many lenses, XF400 video

Hilarious! True. 


You know, now that mention it, there was a temporary table setup right behind where I was filming. On it was a flight case with monitors and camera switching equipment for live-streaming. I wonder if that's what caused my issues. I'm going to reach out to them to see what all they had going on Saturday so I can avoid it next time. Thanks again!

Did that setup have a tall pole with an antenna on top that looked like this?

Shure UA874 Active Directional Antenna UA874US B&H Photo Video (

Maybe you walked in front of the line of path between the wireless mic and the active microphone directional antenna.


Rebel XT, 7D, 5Dm3, 5DmIV (current), EOS R, EOS R5 (current)


Far from an expert as many of you know but would the interference be the same as magnetic "influence?"

Canon EOS T7; EF-S 18-55mm IS; EF 28-135mm IS; EF 75-300mm; Sigma 150-600mm DG



RF is electromagnetic radiation (as are light waves) but I think you are probably thinking about the impact from strong non-cyclical or slowly cycling magnetic fields such as those caused by rare earth magnets, speakers, and power transformers as a few common examples. 


These can cause electronic "glitches" but RF generated interference is a far more common cause than very strong magnetic fields which are quite uncommon at the level necessary to cause electronic devices to malfunction.



EOS 1DX M3, 1DX M2, 1DX, 5DS R, M6 Mark II, 1D M2, EOS 650 (film), many lenses, XF400 video


Do you know any other photographers that have shot in that church to se if they had issues?

John Hoffman
Conway, NH

1D X Mark III, Many lenses, Pixma PRO-100, Pixma TR8620a, LR Classic

Hey John, yeah, that's a good thought. 

I was filming video on my EOS systems (5DmkIV and EOS R) but there were two photographers there shooting photos on their 5D's. Since photos are quick and write a small file to their cards, they said their photos are all fine. 

So I'm going to contact the church and see if I can go test my camera again there - same camera, same card, and try to record a 21 minute clip from the same spot I was standing. 

I did record a 21 minute clip at home on the same camera/card since this happened and everything works perfectly.