topic Canon 5D Mk III Black circles! - Help! in EOS DSLR & Mirrorless Cameras

Canon 5D Mk III Black circles! - Help!

JC1001 — Sat, 21 Feb 2026 17:15:31 GMT

Hi,
I've used the 5D for the first time today having been spoilt with the 70D.
I'm using a Tamron 18-200 AF VC lens with a skylight filter and the photos have come out as a circular good image in the centre with a black outside. Any suggestions... other than go back to the more point and click 70D?

Re: Canon 5D Mk III Black circles! - Help!

rs-eos — Sat, 21 Feb 2026 17:28:29 GMT

That lens was designed for an APS-C (cropped) sensor. The 5D series is full-frame so the lens won't cover the entire sensor.

Going forward, look at EF lenses for your 5D series camera (avoid EF-S lenses).

Some (all?) of the newer R-series full frame cameras allow for one to set a mode to use the smaller portion of the sensor to work with such lenses. But you'd have to check compatibility. Though there's also two types of lenses here too (RF and RF-S).

Re: Canon 5D Mk III Black circles! - Help!

shadowsports — Sat, 21 Feb 2026 17:33:52 GMT

Greetings,

If you are identifying your gear correctly, the 5D has a full frame sensor. The Tamron 18-200 is an APS-C lens. It is not compatible with your 5D.

Re: Canon 5D Mk III Black circles! - Help!

stevet1 — Mon, 23 Feb 2026 00:58:52 GMT

JC1001,

All is not lost though.

Unless, or until you decide to get a different lens, one option is to crop your image to a 1:1, or square aspect ratio, or do a freehand crop and just use what's in the center part of your image.

If you are using a computer, a free and easy-to-use editor for jpegs is Irfanview.

If you are using a mobile device, or tablet, a free and easy-to-use editor is Snapseed.

Here's a copy of your picture that I edited on my Tablet using Snapseed. I cropped it to the 1:1 aspect ratio, and using the mask brush, I brushed out the blue corners.

It's still usable, I think.

Steve Thomas