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12/29/2004 11:59:07 AM · #1 |
I had little problem that scared the hell outta me when I was on vacation last week. As i was working on some pics a the end of the day I noticed tha ta lost of the one I had taken that day had a weird smudge all across the top. I only noticed on the skies. Weird thing is that in only happened in a few pics that day, that was it. I checked everything to make sure nothing was dirty, filters, lenses, etc adn everything checked out so i thought it might be the sensor but if it was the sensor, wouldnt be it on on every picture? I'm totally baffled so I thought I'd ask your opinions. Here's a couple samples. The first one is a resized image and the second one is a 100% crop. BTW, the smudge looked exactly the same on every picture. Here.
June
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12/29/2004 12:01:59 PM · #2 |
| end of the camera battery charge? |
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12/29/2004 12:03:03 PM · #3 |
ooooh, spooky!
Looks like the swirly around stuff that is in my eyes that I see everyday!
Any chance that it could have been condensation on the lens at the time?
Darren
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12/29/2004 12:04:11 PM · #4 |
It probably wouldn't show up on every picture, only those with a small aperture (f/11-f/22 or so) because that keeps the most in focus. A large aperture wouldn't keep the 'blur' in focus enough to see it.
Not sure what the smear is...looks scary. :-(
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12/29/2004 12:04:59 PM · #5 |
when and where it shows up will depend on your settings. the higher the f-stop and the longer the shutter, the more likely it is to show up. it also depends on what you are shooting. here, the clear sky shows it up. if you had no sky, but only the buildings, you might not notice it.
this looks to me more like something on your sensor. to be sure, shoot a white piece of paper at f/32, using various lenses. you'll find out really quickly if it's the lens or the sensor.
good luck!
Message edited by author 2004-12-29 12:05:34. |
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12/29/2004 12:08:31 PM · #6 |
Originally posted by chiqui74:
I had little problem that scared the hell outta me when I was on vacation last week. As i was working on some pics a the end of the day I noticed tha ta lost of the one I had taken that day had a weird smudge all across the top. I only noticed on the skies. Weird thing is that in only happened in a few pics that day, that was it. I checked everything to make sure nothing was dirty, filters, lenses, etc adn everything checked out so i thought it might be the sensor but if it was the sensor, wouldnt be it on on every picture? I'm totally baffled so I thought I'd ask your opinions. Here's a couple samples. The first one is a resized image and the second one is a 100% crop. BTW, the smudge looked exactly the same on every picture. Here.
June |
That looks like sensor dust to me. It is probably only apparent on images with very small aperture. I noticed that this example was taken at f/32. Check to see if that is the common link between the photos that have the smudge.
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12/29/2004 12:09:22 PM · #7 |
Given that the temperature was below freezing and the lens was a sigma, not noted for extreme quality control, I suspect a failure of sealing on the lens elements and internal condensation from wshifting from warm environment to outdoors.
Robt.
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12/29/2004 12:13:44 PM · #8 |
| ewwwwwwwwwwwww....looks like sensor goo. Happened to me once when i shot frozen compressed air on my sensor. Its really spooky when blown up and looks much like a fungus under a microscope. If you take your lens off and open the shutter, you will be able to see it on your sensor...if its there. Then you have to clean it. I think the sensor's can handle much more abuse than we give them credit for. I wiped mine off with a piece of cotton...out of desperation. Then blew UNfrozen compressed air to get all the cotton bits out. Good luck.... |
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12/29/2004 12:24:26 PM · #9 |
Originally posted by grigrigirl:
ewwwwwwwwwwwww....looks like sensor goo. Happened to me once when i shot frozen compressed air on my sensor. Its really spooky when blown up and looks much like a fungus under a microscope. If you take your lens off and open the shutter, you will be able to see it on your sensor...if its there. Then you have to clean it. I think the sensor's can handle much more abuse than we give them credit for. I wiped mine off with a piece of cotton...out of desperation. Then blew UNfrozen compressed air to get all the cotton bits out. Good luck.... |
*gasp*
Let me guess, a Brillo Pad next?? ;-)
Holy cow, those methods are scary!
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12/29/2004 12:43:43 PM · #10 |
Although the scenario proposed by bear_music is possible, I doubt that it is responsible. Far more likely that there is crud on the sensor. To me it looks like a very long thread/fuzz that is lying on the sensor. Some parts are in better focus than others. Shooting at f/32 will make this appear much worse (BTW, unless you absolutely need f/32, you are reducing your image sharpness due to diffraction effects. Best to go with f/22 or less in most cases).
To remove this, I wholeheartedly recommend the copper hill cleaning method. It yields ggreat results in a minimum of time, without blowing dust around inside the camera, and best of all, the materials are relatively inexpensive. The downside is, you may have a hard time finding the recommended cleaner in your current location. An alternative is a very high grade purified methanol, you want something that specifies less than 5 ppm residue. It's available from chemical suppliers, and was priced at about $25-30 USD per half-liter, last I looked. Not that you need a half-liter, that would last you a century, LOL.
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12/30/2004 10:32:54 AM · #11 |
OK, I did the white sheet test and it turns out it's worse than I thought. Here. NOw what?
June
Edit: I used two different lenses for the test.
Message edited by author 2004-12-30 10:34:18.
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12/30/2004 10:37:12 AM · #12 |
Order Eclipse and Pec Pads from Copper Hill (which Kirbic noted earlier) PRONTO! Do not blow or insert anything into your camera (dabbing your sensor with chewing gum obviously didn't work out). While you're waiting, you might want to limit yourself to apertures of 8 or less to minimize the problem.
Message edited by author 2004-12-30 10:41:04. |
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12/30/2004 11:10:06 AM · #13 |
Originally posted by ButterflySis:
Originally posted by grigrigirl:
ewwwwwwwwwwwww....looks like sensor goo. Happened to me once when i shot frozen compressed air on my sensor. Its really spooky when blown up and looks much like a fungus under a microscope. If you take your lens off and open the shutter, you will be able to see it on your sensor...if its there. Then you have to clean it. I think the sensor's can handle much more abuse than we give them credit for. I wiped mine off with a piece of cotton...out of desperation. Then blew UNfrozen compressed air to get all the cotton bits out. Good luck.... |
*gasp*
Let me guess, a Brillo Pad next?? ;-)
Holy cow, those methods are scary! |
when your sitting in your car, having just parked and grabbing camera gear to shoot a wedding because you just drove 2 hours from a company picnic shoot and suddenly discover sensor goo because you followed someone else's advice to blow compressed air with the camera upside down...well...you grab a darn cotton napkin and do what you can do! When I went to jamaica, the airport wouldnt let me take compressed air in my luggage. I had bits of dust all over my sensor after the first day of shooting, so desperately grabbed a hairdryer and gave the darn sensor short bursts of air THAT way! lol...scary but true. These cameras are STURDY i tell you! The hairdryer incident was before the saturation by full glass of wine incident. She's still kicking.... |
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