EOS R8 Weird dark border + bright patches

[fisherman10]

Hi everyone, would anyone know what would be the cause of these issues. There is a dark band on the top and bottom edges (landscape) or left and right edges (portrait). There is also a bright patch/haze right after the dark band.

I can see the dark band in the viewfinder and the screen before taking the photo. All photos jpg straight out of camera. Using EFCS. NOT electronic shutter. First 3 photos with the lady taken with flash, last 2 photos of the white wall taken without flash.

Canon R8, Canon EF 100mm MACRO USM and Canon EF 24-105 F4, 3rd party EF-R adapter.

To add to that, I also see the same issue on the screen preview and viewfinder BEFORE taking the photo.

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[SignifDigits]

If you have access to any RF lens to put on the camera, even at a store, you can test narrow it down that way as well.

My Canon adapter opening is clearly larger than your third-party adapter.  IMO it's not worth your time to rent one.  Send yours third party adapter back for a refund and get a new or used Canon adapter from a reliable source.    As of this writing Canon has them refurbished right now for $119 - https://www.usa.canon.com/shop/p/refurbished-mount-adapter-ef-eos-r 

[fisherman10 · Accepted solution]

Thank you everyone for the replies and suggestions. It is indeed an issue with the 3rd party adapter.

I tried grinding the adapter (savagely 😂) and the issue seems to have resolved.

[SignifDigits]

Bravo for inventiveness there!  I would recommend being SURE you blow the heck out of it with a high-pressure air hose - you just made a gazillion pieces of microplastic to land on the back of your lens and your camera sensor.  Wouldn't be worth the optical train risk for the savings to me, but I am a tightwad and totally get making what you have work.  Again, please blow that thing out with high-pressure air for a long time, and every angle imaginable, and best of luck to you.

[jrhoffman75]

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@fisherman10 wrote:

Thank you everyone for the replies and suggestions. It is indeed an issue with the 3rd party adapter.

I tried grinding the adapter (savagely 😂) and the issue seems to have resolved.

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Another data point to counteract the contention "It's just an empty cylinder, why spend all the money for a Canon brand adapter" 😀

[SignifDigits]

John, that is true but lost time and lost photos and aggravation are not great tradeoffs for some people.  Fixing this one makes sense as long as no particles become an issue, and the adapter performs well long-term.  I hope it does and applaud the inventiveness, and, all great and wonderful if it does.   That said buying the Canon adapter would have avoided the time, energy and corrupted photos, so I'm still only comfortable recommending those.

[fisherman10]

Haha yes I did! I have a air compressor with filtered nozzle. I made sure to brush and blow a few times after trimming.

[ebiggs1]

"Another data point to counteract the contention "It's just an empty cylinder, why spend all the money for a Canon brand adapter""

Yes sir, it certainly is.