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Gear Talk => Technical Support => Topic started by: VelocideX on April 11, 2013, 07:12:04 AM

Title: Is this dust or sensor damage?!
Post by: VelocideX on April 11, 2013, 07:12:04 AM
Attached is a highly cropped image from my 5D3. There is a black/purple spot about 5 pixels by 2 pixels. What is this? Dust? Sensor damage?! Help!

I should say this was taken at about f/2

Thanks
Title: Re: Is this dust or sensor damage?!
Post by: rwmson on April 11, 2013, 07:26:34 AM
My guess is that it is dirt on the sensor.  You could lock up the mirror and look at the sensor.

Also, is it in EVERY shot?  With different lenses?  This would also indicate dirt on the sensor.
Title: Re: Is this dust or sensor damage?!
Post by: rmt3rd on April 11, 2013, 08:29:40 AM
dust shouldn't show up at f/2, but see if it is more pronounced stopped down.
Title: Re: Is this dust or sensor damage?!
Post by: SwampYankee on April 11, 2013, 08:36:34 AM
Well the good news is that the camera is probably less than a year old so it is under warranty.  Do no, repeat, do not muck with the sensor.  Do not attempt to clean it yourself. Pack this up and send it to Canon today.
Title: Re: Is this dust or sensor damage?!
Post by: Sporgon on April 11, 2013, 09:09:18 AM
Well the good news is that the camera is probably less than a year old so it is under warranty.  Do no, repeat, do not muck with the sensor.  Do not attempt to clean it yourself. Pack this up and send it to Canon today.


Yep, from what you have posted there's no way that's dust. ^ is sound advice  :-\
Title: Re: Is this dust or sensor damage?!
Post by: Alex on April 11, 2013, 10:15:17 AM
It could just be a cluster of stuck pixels... Its a really easy fix, I had it on my new 5D 3. All you have to do is go to manual sensor clean then remove the lens hold the camera under a bright light for 2or 3 seconds, lens back on and take another shot... Best to find crop in on the older pic then move to the new one to see if it has gone. If it doesn't work first time try it again with a slightly longer time under the light... Try it, it cant hurt your camera and might save you waiting for a week
Title: Re: Is this dust or sensor damage?!
Post by: Mt Spokane Photography on April 11, 2013, 12:58:39 PM
Do a little more testing to narrow it down. Its hard to fix a issue until you understand just what it is.
Take a 5 second exposure with the lens cap on.  (Use AI Servo)  This will let you see if any pixels are stuck "ON", but seeing the ones that are off is more difficult.
 
Set the aperture to f/22, but the lens in manual focus and set it to mfd, and take a shot of a evenly lit portion of the sky or white wall.  Dirt and dust blobs of verying sensities will show up. A block of pixels that are stuck off are obvious.   Usually, most dust will merely blow away with use of a rocket blower while the camera is in the manual clean mode.  If that doesn't work, Canon will clean it for you, but it might not be covered under warranty, so ask.  They are not always consistent about this, if you just received it dirty its one thing, but owning it longer might be treated differently.
Title: Re: Is this dust or sensor damage?!
Post by: iseowl on April 11, 2013, 01:54:08 PM
I had this issue.

I had a lot of specs in my pictures. I thought it was dust so I bought a self cleaning sensor kit. Cleaned it & used a rocket blower.

Specs were still there. I then took it to a camera repair shop that does sensor cleaning, under the assumption that I wasn't cleaning it the correct way. The person worked on it for an hour & the specs were still there.

He asked me if I have encountered lasers with my camera which I have as I work in nightclubs.

I got him to send it off to Canon & I'm going to probably get the sensor replaced  :-[ :'(
Title: Re: Is this dust or sensor damage?!
Post by: Mt Spokane Photography on April 11, 2013, 02:00:06 PM
I had this issue.

I had a lot of specs in my pictures. I thought it was dust so I bought a self cleaning sensor kit. Cleaned it & used a rocket blower.

Specs were still there. I then took it to a camera repair shop that does sensor cleaning, under the assumption that I wasn't cleaning it the correct way. The person worked on it for an hour & the specs were still there.

He asked me if I have encountered lasers with my camera which I have as I work in nightclubs.

I got him to send it off to Canon & I'm going to probably get the sensor replaced  :-[ :'(

Yup, lasers ruin sensors instantly, turn your camera off while lasers are on.  Probably not covered by warranty either, though Canon is pretty lenient.
Title: Re: Is this dust or sensor damage?!
Post by: VelocideX on April 11, 2013, 05:04:21 PM
OK so I've cleaned the sensor with a rocket blower and exposed the sensor to light for a few seconds as suggested and the spot is still there. The geometry looks slightly different though - the ratios of the intensities in different pixels are slightly different. Perhaps I've slightly dislodged something that's there?

Note that there is still intensity in the pixels - they aren't black and so aren't totally dead.

I have done a bit of nightclub work with lasers before. I've seen millions of photos from clubs with lasers so wasn't aware that this was a problem!

I guess the next step is to get the sensor cleaned at a camera shop to see if that makes a difference.

I'll be very disappointed if I've damaged the sensor :( I've only had the camera four months.


Title: Re: Is this dust or sensor damage?!
Post by: SwampYankee on April 11, 2013, 05:29:18 PM
Lasers usually destroy the sensor in lines.  maybe this is a spot, maybe not.  I really think you should stop mucking with it as it is under warranty.  Send it in and find out.  Yes you will be without it for at least a week but if you so some damage to the sensor you will be sorry.  Here is what laser dmage looks like http://petapixel.com/2011/07/08/canon-5d-mark-ii-has-sensor-destroyed-by-concert-lasers/ (http://petapixel.com/2011/07/08/canon-5d-mark-ii-has-sensor-destroyed-by-concert-lasers/)
Title: Re: Is this dust or sensor damage?!
Post by: Aglet on April 11, 2013, 07:12:48 PM
OIL spots can be very dark, large and persistent and slightly INconsistent - don't often get these with Canon but not impossible.
Oil spot appearance, if large enough to show up below F/8 or so should be visible with a good sensor loupe.