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Old Jan 4, 2010, 2:06 PM   #11
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...if not, can you lock the mirror up for cleaning and take a close look at it from different angles using a bright light to see if anything obvious is on it?
I'd probably do that first (very close inspection, just in case the AA filter over the sensor has a crack in it right there or something causing the problem, so that you don't risk getting any cleaning solution under it if it is cracked).
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Old Jan 4, 2010, 2:41 PM   #12
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one more point to add is that i have a battery grip so the release button would on the bottom for portraits. I'll do some close looking. Thank you for your advise!
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Old Jan 4, 2010, 3:40 PM   #13
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So I've run some tests and can make the problem happen every time.

- I took the lens off and had a careful look of the sensor. No issue
- Thinking that perhaps light was coming in through the lens mount at the release button, I put a flashlight close to the button again. No issue
-Took photos pointing the camera at the computer monitor. No issue
-Took photos looking through the window to a bright backyard/snow/high contrast. Zoomed in and out. PROBLEM OCURED both in RAW and JPG modes
-Placed my hand around the lens mount area keeping light out. PROBLEM OCURED.
-Shawn a flashlight into the front of the lens. No issue
- Snugged up the lens mount screws, one was a fraction looser than the other 3. Didn't fix the problem
- Shot H2 ISO and L ISO, overexposed, underexposed. PROBLEM OCURED
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Old Jan 4, 2010, 3:57 PM   #14
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One more thing I wanted to mention is that though these last photos and the skating photos were done during daylight/high contrast, the sailboat ones were shot well before sunrise when it was quite dark.
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Old Jan 4, 2010, 4:57 PM   #15
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That's really odd. I'm wondering if you have a shutter curtain issue of some type then.

Perhaps I'm wrong. But, I've never seen this of problem with a digital camera (which is why I was suspecting extra light was getting in through the lens mount area or lens release button, causing that odd brighter spot on one edge).

A digital camera is going to electronically reset the sensor before each exposure and read it after it closes the shutter curtains, and it may be doing a column type of readout. Usually that's the kind of symptoms you'll see with a sensor issue (banding, or column related types of issues, but not the shape of the brighter spot in your images). Your symptoms look more like extra light is coming in through somewhere other than the lens on one side while the shutter is open.

That's very strange (it does not look like an electronic type problem to my eyes).
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Old Jan 4, 2010, 6:15 PM   #16
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Originally Posted by spy View Post
... I hate being the "lucky" one. Should maybe go buy a lottery ticket.
Buying a lottery ticket?!?!?

If I had your luck I'd think twice before crossing the street!
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Old Jan 4, 2010, 6:40 PM   #17
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I think it looks more like an unused portion of the image circle reflecting off something inside the mirror box.
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Old Jan 4, 2010, 6:40 PM   #18
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I'll still cross the street but I think this time I'll look both ways.

I thought it was strange that I could shine the light around the outside of the lens as well as straight on the front of the lens and also take an inside shot with no issues displayed but point the camera to the outdoors and the issue would pop up. So then I tried shooting with the lens cap on on bulb mode and put the camera under a lamp. The only place light leaked in was through the view finder but it showed a completely different light leak which I knew light would enter there.

I then thought that perhaps the issue is not from light coming straight in but rather entering the lens on an angle. I shot the under side of my lamp on an angle and got these results.
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Old Jan 4, 2010, 6:48 PM   #19
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Do you have an eyepiece cover for your viewfinder, so you could try it to make sure it's not coming in from somewhere else?

It looks like it may be better to let Canon figure it out. But, I'm really curious as to what's causing it (and I'm thinking that the more info you can give them, the better, in case they haven't seen this before).
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Old Jan 4, 2010, 7:59 PM   #20
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This is what I think is happening:
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