Red flair with long exposures.

[andytraff]

6Dll, 24-105 lens, 30 sec. F.4 3200. Getting red flair on the bottom of all frames. Whats up? Thanks!

[Waddizzle]

Does it show up in all photos, no matter where you take them?  That looks like vehicle tail light to me.

[Peter]

5D IV had the same but firmware 1.0.4. solved the problem.

"Fixes a phenomenon in which a red-colored area may appear at the bottom-center of a captured image when shooting in bulb mode or during a long exposure."

When I tried some long exposures with my two 6D I got the same red light with my new 6D (but not the old). Only visible at really high ISO so I didn't care about it. I tried today with ISO H2 and 30 seconds. No red light. Strange.

At that time, some months ago, I thought it was light leak or something from my 24-105/4L IS. I put my new 6D in a dark room and got the same red spot at ISO H2 and ISO H1 and 30 seconds. Tried to remove it with a dark frame but no really luck.

[Peter]

Tried again with 24-105. Visible. With 70-200, not visible. Seems to be 24-105/4L IS at wide focal length like 24 mm but not 50 mm or 105 mm.