What is this I am seeing on my images - G11

I have taken some star shots and am playing with the DPP from Canon and adjusting the RAW imaging by adjusting the levels (basic left right level adjustments)

And when I really adjust it, all of my images have this blow out in the upper left hand corner.

I took a random shot in a different area (to rule out scattered light source) but that is not the case. This seems to be an issue with my sensor???

Here is a shot with levels really stretched to show the issue and then one where I didnt exagerate it so much. NOTE: you cant see it unless I blow out the levels....but what is this?

Notice the purplish "mess" in the upper left corner....this is what I am referring to and questioning!

And here is one more image...again, I totally blew the level out so you can see the purplish blob in the upper left corner. Its always in this same spot.

anyone?

Hey, it doesn't cost anything to guess. I would guess maybe something is just off screen in that direction, like perhaps the moon, and your extra boosting is bringing out some of the minimal light?

Dennis

kezug wrote in post #10012940
anyone?

If you have bad thought's about the sensor, why not take a few shots of the sky with the body rotated . i.e. 90degrees and 180degrees.

That should give you some frames from which you can make some clear assessment.

A GHOST!!!!

Just out of the curiosity i've cheked my G11 and ofcorse there is no such thing in my pics. As you can see on my old Olympus pics down below, I had a similar problem. On every pic I had that dark spot in the same shape on the same place...I've been told that "some pixels are burned" or something on the sensor...donno how that happens. But I thank god for that burned pixel every day...those pixeles made my get my G11. hahahah! So now I got all paranoic and did that tweeking in DPP to se if any thing pops out on the G11 images, and nothing...good thing about your defect is that is in the corner and you can crop...start planing your frames bit different, don't forget you got dirt in the angle and thats it. If you do check that out, please tell me what is it. I am curious!
good luck...
Oh yeah...that "shape" is just above that cloud in the middle

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I would guess that it has something to do with heat... Try doing another one when the camera hasn't been used in a few hours and see if it still happens.

Yeah Kezug, take a shot every 6 hours! hahahaha...no way, that G11 does not get overheated! I doubt it will work.

OP, does it do it in all shots,,, or just long exposure night shots.... If it gets worse as the exposure time gets longer it is heat. If it does it in daytime pics too it is another issue.

Older DSLR's and even some newer one's produce purple corners on long exposures due to heat; the images look exactly like the images posted by OP. Use the search button and you will find several instances of this regarding long exposure photography. My 1D does this at around 30 seconds,,, if the camera is cold when I start they do not appear.

Tadaaa wrote in post #10013603
OP, does it do it in all shots,,, or just long exposure night shots.... If it gets worse as the exposure time gets longer it is heat. If it does it in daytime pics too it is another issue.

Older DSLR's and even some newer one's produce purple corners on long exposures due to heat; the images look exactly like the images posted by OP. Use the search button and you will find several instances of this regarding long exposure photography. My 1D does this at around 30 seconds,,, if the camera is cold when I start they do not appear.

Woooow Amigo!!!!! TRUE!
I did click that search button...hahaha
They all do say so about the 1D...
Anyway I understood that this happenes in all his shots, like my Olympus. In my case you see it on clear day and here at the night, so I guessed...

Tadaaa wrote in post #10013603
OP, does it do it in all shots,,, or just long exposure night shots.... If it gets worse as the exposure time gets longer it is heat. If it does it in daytime pics too it is another issue.

Older DSLR's and even some newer one's produce purple corners on long exposures due to heat; the images look exactly like the images posted by OP. Use the search button and you will find several instances of this regarding long exposure photography. My 1D does this at around 30 seconds,,, if the camera is cold when I start they do not appear.

Thanks for this infor....last night, when I first noticed it, it was from taking long exposures. However, it must have been about 50 degrees and I was taking about 20 shots at about 30 seconds each. On 2, I tried a 2 minute exposure. I was at a Golf course parking lot doing this.

When I got home and started editing some shots by playing with the levels in DPP, I noticed the purple corner. At that time, I thought that it was from a light source from a subdivision to my back left of where I was shooting, but then I went immediately out side, and took a 20 second exposure and went back to DPP and same thing showed up.

However, now that my camera has rested, I can try again with a much shorter exposure and even a 20 second one again and see if I see it again and will report back.

I am doubting its heat related.

I hope for you it is heat related....

I'm thinking either heat or the autofocus assist lamp.
Looking at my camera again maybe its residual heat from the autofocus assist lamp.
Try turning it off in the menu well before you intend to use the camera for night shots.

The best way to combat such things is take shorter exposures and then stack them in a program like Registax.

Astronomers like myself have been using this gem of a program for some years now and it really allows you to bring out the detail in images.

Google it, download and give it a try.

kezug wrote in post #10014446
Thanks for this infor....last night, when I first noticed it, it was from taking long exposures. However, it must have been about 50 degrees and I was taking about 20 shots at about 30 seconds each. On 2, I tried a 2 minute exposure. I was at a Golf course parking lot doing this.

When I got home and started editing some shots by playing with the levels in DPP, I noticed the purple corner. At that time, I thought that it was from a light source from a subdivision to my back left of where I was shooting, but then I went immediately out side, and took a 20 second exposure and went back to DPP and same thing showed up.

However, now that my camera has rested, I can try again with a much shorter exposure and even a 20 second one again and see if I see it again and will report back.

I am doubting its heat related.

Well all the one's that did it were long exposures right,,, the inside of the camera gets hot processing all that... Try a normal exposure,,, say 1/60 of a second? What happens... ambient temperature doesn't really matter I'm talking about heat being created in the camera.