6D and light leak?

[Peter]

I took some pictures at ISO >25600 and found a lightspot down in the right corner. I am wondering why just one corner? It is not like the 5DIII:s light leak, because this will appeare in a dark room and always in the same corner. Is it warmer in that corner and results in more noise?

http://imageshack.us/photo/my-images/233/img0605rr.jpg/

It is not a real problem, but I am curious.

[Mykolas]

Hi Peter,

I would like to ask a few questions about this if you do not mind.

1. Was this shot taken with the lens cap on?
2. Was this shot taken with the camera on a tripod?
3. Were you looking through the viewfinder at the time?
4. Was the viewfinder completely covered when you took this shot?

If this is a time sensitive-matter, additional support options are available at Contact Us.

[Peter]

1. Was this shot taken with the lens cap on? Yes, but even without there will be a light leak.
2. Was this shot taken with the camera on a tripod? No
3. Were you looking through the viewfinder at the time? Yes
4. Was the viewfinder completely covered when you took this shot? No.

I am just wondering why just one corner will light up. I will try some new shots.

[Peter]

Okey, here we go:

1. Was this shot taken with the lens cap on? Yes, in a dark room
2. Was this shot taken with the camera on a tripod? No
3. Were you looking through the viewfinder at the time? No, but live view was not used.
4. Was the viewfinder completely covered when you took this shot? yes.

Raw image you find here: http://kameratrollet.se/allt/6d.CR2

I tried 4 seconds at different ISO. Only at H1 and H2 the light in the right corner appears. I suppose the sensor is warmer in that corner than in other places, so my question is why?

I don´t think I will use H1 and H2 at all, but I am curious.

http://kameratrollet.se/allt/6d2.CR2 shows a picture that is taken at H2 and 1/800 seconds. the right corner is lighted up.

Noise reduction for long expsure will remove the lighted corner, but only for pictures with longer exposure than 1-4 seconds.

[hsbn]

I did some night shot over the weekend and experienced the same problem with ISO6400 and 30s exposure also.

[Peter]

Then I assume many more of 6D have the same light leak.

[TCampbell]

It may not be a "leak" at all.

When you crank the ISO really high, you get a lot of noise in the image -- you already knew that.  But there is a relationship between the physical temperature of the chip and the amount of "noise".  You also notice the pattern noise (and that's normal -- all sensors do it).  If you were to chill the camera by being outside with it an hour or so, then repeat the same test and compare the images, you'd notice that the images taken wtih a very cold sensor have noticeably less noise than the images taken with a warm sensor.  The opposite is also true -- if the camera is used in very hot temperatures then it will have a lot more noise in the image.

I'm wondering if your sensor wasn't simply "physically" warmer in that corner, making it have more noise.

[Peter]

Maybe it is. The only question I have left is why we haven't seen the same thing from other models from Canon.

[ddyourself]

The only explanation is Canon rushed to build a cheap full frame to compete with D600. They squeezed every corner and saved every penny on quality control.