pink at high iso's

i was just reading some threads and stumbled upon someone seeing pink spots on the bottom of the frame on their 5d ii at high iso. so i looked at a couple shots of my own i took at 25600 iso to see if i noticed it, and it looks like i see the pink at the bottom right mentioned. is this normal at high iso? or is this something canon will fix? these shots are sooc, i adjusted the exposure on one but the pink was still there prior to that. the sky had some pink to it that evening, so that may be normal. just more concerned with the pink on the bottom right of the frame. appreciate any input.

That would probably bug me too, but I'd try real hard to ignore it because I know that it would never be a problem in any of my real world shooting.

Yes, those spots are normal. When using hi ISO such as your example you literally are "overcharging" your sensor to make it very sensitive. Each sensor point is scrambling for information and if it doesn't get any fast enough it begins to make up its own information. Hence noise. Areas around the edges tend to heat at different rates and as the heat goes up so does the noise. This is a tough situation for long exposure photography or high iso photography. This phenomena exists across all CCDs and is particularly a PITA for astronomers who end up "icing" their specialized cameras.

Kinda like kicking up the speed of a conveyor belt. There is a lot of information out there on how CMOS sensors work. The more you know about it and how it reacts under certain conditions, the more you will know how to push your camera to it's limits.

Edit: The example link you posted appears a bit more extreme and appears to be more of a sensor issue. Corner areas are notorious for generating more noise. If I saw a band across my sensor I would be more concerned not for high iso situations but for potential hot pixel generation.

Does the camera function properly in 'normal' use at 'normal' ISO values. It looks like you are trying to find a problem that you have read about, just because you can...

Do you use this high an ISO normally?

NinetyEight wrote in post #12861820
Does the camera function properly in 'normal' use at 'normal' ISO values. It looks like you are trying to find a problem that you have read about, just because you can...

Do you use this high an ISO normally?

i do not normally bit when i do, id prefer not to see any pink if possible. if its normal, i can probably live with it. i havent noticed any hot pixels though. its still under warranty so wanted to know if its something to send it in for before it expires

Keep looking, I am sure you will find that hot pixel, it's bound to be in there somewhere!!!!

NinetyEight wrote in post #12861820
Does the camera function properly in 'normal' use at 'normal' ISO values. It looks like you are trying to find a problem that you have read about, just because you can...

Do you use this high an ISO normally?

One of the 3 I had was so bad, you could see impacts at ISO 1600. It was faint and would appear only in certain exposures, but it was there, and the corner got brighter each level up. Other areas were blotchy as well. I sent it in, they seem to make it better, in the end, it went to a new owner that didn't shoot high ISO. Some units have this worse than others, I think it must have something to do with the sensors themselves due to the variances from one to another. The last one I had didn't really show this at all. My 1D4 has it as well.

john_galt wrote in post #12862314
i do not normally bit when i do, id prefer not to see any pink if possible. if its normal, i can probably live with it. i havent noticed any hot pixels though. its still under warranty so wanted to know if its something to send it in for before it expires

It wouldn't hurt to send it in, but if you only use it for the odd shot and don't usually have an issue with it you may wish to put up with it rather than lose the camera for a week or so.
I assume that ISO25600 on the 5D is one of the expanded ones in software? This could be a 'feature' of the way the software works?

TeamSpeed wrote in post #12862511
One of the 3 I had was so bad, you could see impacts at ISO 1600. It was faint and would appear only in certain exposures, but it was there, and the corner got brighter each level up. Other areas were blotchy as well. I sent it in, they seem to make it better, in the end, it went to a new owner that didn't shoot high ISO. Some units have this worse than others, I think it must have something to do with the sensors themselves due to the variances from one to another. The last one I had didn't really show this at all. My 1D4 has it as well.

If it's coming in at ISO1600 then there is a problem but if was just at the very high (25600 fir instance) this could just be a trade-off of having such high ISO's available. Sounds like it's a bit of a design 'feature' if its affecting your 1D as well

NinetyEight wrote in post #12863645
It wouldn't hurt to send it in, but if you only use it for the odd shot and don't usually have an issue with it you may wish to put up with it rather than lose the camera for a week or so.
I assume that ISO25600 on the 5D is one of the expanded ones in software? This could be a 'feature' of the way the software works?

If it's coming in at ISO1600 then there is a problem but if was just at the very high (25600 fir instance) this could just be a trade-off of having such high ISO's available. Sounds like it's a bit of a design 'feature' if its affecting your 1D as well

I think you will see this on many bodies actually and not just at 25600. Just taking a test shot in a dark room with the body cap on at ISO 3200, 6400, and 12800 will show this "noise", if the camera has an issue. It just goes up in intensity as you move higher in the ISO range. It is consistently along the bottom edge and right corner though, in the different units I have seen this on. You just learn to live with it, I believe.

Here is a 6400 lens-cap dark-room sample from the one I sent in. Sure I auto-leveled to make the noise much worse than it was, but it still very blotchy noise that has impacts on IQ. At 1600, I could just make out a bit of pink in the lower corner in some pictures that had darker exposures.

The 5d2's true max iso is 6400 I believe, so when you take the picture it underexposes and then boosts in 2 stops before saving. I would recommend longer exposures (much longer) at low iso's because you are on a tripod and taking a picture of a still city, would look tons better with no noise I agree, but sending it back wont do anything, it's the fact that the sensors they put in are not good enough.

Dooms_day wrote in post #12864345
The 5d2's true max iso is 6400 I believe, so when you take the picture it underexposes and then boosts in 2 stops before saving. I would recommend longer exposures (much longer) at low iso's because you are on a tripod and taking a picture of a still city, would look tons better with no noise I agree, but sending it back wont do anything, it's the fact that the sensors they put in are not good enough.

I beg to differ, they are good enough, like I said, I had enough samples to see a large variance in performance. There are some that won't show this, or very, very minimally. I don't see this on my 7D at all, for example, but do on the 1D4. And sending it back did improve the overall issue a little (they did some wb changes?), but it still didn't please me.

thx all. i think i can live w/ this then rather than send it in and gamble if it'll get fixed. sounds like it'll be a hit or miss type thing. only happens on the expansion h2 h1 iso's for me so not too bad.