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Blue_In_AK Donating Member (1000+ posts) Send PM | Profile | Ignore Mon Apr-24-06 03:49 PM
Original message
Sensor cleaning question (again)
I purchased the Copper Hill kit to do my sensor cleaning, and I think I've been doing it right because everything looks really spotless down inside there and on my pictures, but I've got this one stubborn spot that I just can't seem to get rid of. I can see it through my viewfinder in the upper right-hand corner, and at certain F stops it shows up in my pictures, too. Do any of you cleaning experts have an idea what this fleck is and how I can get rid of it? It's driving me pretty nutz. It's not on the lens because I see it no matter which lens I use.
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bvar22 Donating Member (1000+ posts) Send PM | Profile | Ignore Mon Apr-24-06 06:42 PM
Response to Original message
1. If you can see it through the viewfinder,
Edited on Mon Apr-24-06 06:48 PM by bvar22
...it is on your mirror, lens, or viewfinder glass.
You won't be able to see a spot on the sensor through the viewfinder.
A spot on your mirror or viewfinder won't show on your photo....so :shrug:
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Blue_In_AK Donating Member (1000+ posts) Send PM | Profile | Ignore Mon Apr-24-06 08:11 PM
Response to Reply #1
2. I'm very perplexed by the whole thing.
Edited on Mon Apr-24-06 08:19 PM by Blue_In_AK
Do you know anything about "pentaprism"? That's where Nicholas at Copper Hill thought it might be, in which case I'll probably have to send it back to Canon to fix, he said, a prospect I'm not really looking forward to because it will leave me cameraless. :(
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priller Donating Member (1000+ posts) Send PM | Profile | Ignore Tue Apr-25-06 12:11 AM
Response to Reply #2
3. If it shows up in some pictures
then it's not in the pentaprism or mirror. Can you see it with all lenses?
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Blue_In_AK Donating Member (1000+ posts) Send PM | Profile | Ignore Tue Apr-25-06 12:28 AM
Response to Reply #3
4. Yes, and even without lenses
just looking through the viewfinder. It's in the upper right-hand corner.
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ConsAreLiars Donating Member (1000+ posts) Send PM | Profile | Ignore Tue Apr-25-06 12:42 AM
Response to Reply #4
5. Whether or not you see it in it in all the images is the key question.
Edited on Tue Apr-25-06 12:45 AM by ConsAreLiars
Take hight resolution pictures of a clear sky or a blank area of a wall at a small aperture and see if it appears there. If you find that defect in every picture then it has to do with the sensor, either some bad elements or dust or a ting scratch. If you don't see it in the image, then it is just a speck of dust somewhere in the viewing system, and unimportant. If it is in the image and thus somewhere on the sensor, then there are some software techniques to "fix" it, and I can fond them for you. But the first thing is to be sure that it shows up in (and thus degrades) you image files.

(Edit to add) If you have a mirror in your camera, like in film SLRs, the dust there would also be visible, but again would not show up on the image.
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Blue_In_AK Donating Member (1000+ posts) Send PM | Profile | Ignore Tue Apr-25-06 12:53 AM
Response to Reply #5
6. It shows up in the pictures (clear sky, etc.)
Edited on Tue Apr-25-06 12:55 AM by Blue_In_AK
with small aperture. I can fix the photos easy enough with PaintShop, but it's just annoying me to death that I can't get rid of it. The sensor looks absolutely spotless - we used HullBoss's jewelry loop to magnify anything that might be on it, but can't see a thing.

I have an e-mail in to Canon to see if they've got any clues. I'll be really upset if I have to send it back down to California for repairs. There's no authorized Canon warranty fixer up here and I'm afraid if I send it off for repair it'll take ages to get back to me. We sent the Mavica down to my daughter to use, so the 20D is the only camera in the house - I'm very attached to it.
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ConsAreLiars Donating Member (1000+ posts) Send PM | Profile | Ignore Tue Apr-25-06 01:15 AM
Response to Reply #6
7. here is the free software for dust speck removal
http://www.polaroid.com/service/software/poladsr/poladsr.html

Haven't tried it since I use film (although it might work with scanners???). The other approack I've seen is software (PWP) specific, since it involves performing a second step that "subtracts' that known defect from each image during processing.
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Blue_In_AK Donating Member (1000+ posts) Send PM | Profile | Ignore Tue Apr-25-06 02:22 AM
Response to Reply #7
8. Thanks.
I downloaded it. I'll let you know how it works.
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F.Gordon Donating Member (1000+ posts) Send PM | Profile | Ignore Tue Apr-25-06 10:42 PM
Response to Reply #6
11. My 1 1/2 cents
It sounds like your sensor is still dirty. Try cleaning it again but before you do clean the area around the "rib cage". It really is kinda' like open heart surgery... you need to clean around the mirror, etc before you crack open the rib cage to get at the heart (sensor). Cause... even after you clean the sensor when you sew back up the rib cage (close it) snot and stuff can fall back in. Does that make sense?

I suspect your viewfinder "issue" is a "juxtaposition" problem.
:rofl:

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Blue_In_AK Donating Member (1000+ posts) Send PM | Profile | Ignore Wed Apr-26-06 12:03 AM
Response to Reply #11
12. Okay, F., I'll try one more time...
I really don't see how the sensor could possibly be dirty still, though, as many times as I've swiped it. But you're saying it could be something around the outside? This spot is very, very stubborn. But if you say so, I'll try again ... complete with my latex gloves and dust mask.

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F.Gordon Donating Member (1000+ posts) Send PM | Profile | Ignore Wed Apr-26-06 12:11 AM
Response to Reply #12
13. Hold up
What I'm sayin' is that even after you clean it other stuff can fall onto the sensor during the process. My first try I had a huge piece of sludge fall onto the sensor but I just used the blowie thing and it went away. It wasn't there in my pre-clean test snap.

How stubborn? Can you post a "test pic" so we can see what's showing up? Just trying to keep you from having to ship off your camera.
:hi:
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Blue_In_AK Donating Member (1000+ posts) Send PM | Profile | Ignore Wed Apr-26-06 01:18 AM
Response to Reply #13
14. Thanks ...
I took some shots this evening, but the "speck" probably won't show up because it was dim light. I'm not giving up on this thing until I've tried everything I can, though. I REALLY don't want to send it down to CA.
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regnaD kciN Donating Member (1000+ posts) Send PM | Profile | Ignore Tue Apr-25-06 03:02 AM
Response to Reply #4
9. This is really weird...
It seems to me that, if it's in the mirror or pentaprism, it won't show up in photos...but this shows up in photos.

On the other hand, if it's in the sensor, it would only show up in photos, but not in the viewfinder...but this shows up in the viewfinder.

And if it were a problem with one of the lenses, it would only show up when that lens is on the camera...but this shows up even with no lens on the camera.

Unless you happen to have a sensor problem in the exact same location of the image as a completely separate problem in the mirror or pentaprism, I can see no possible explanation for what you're experiencing. :shrug:

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Blue_In_AK Donating Member (1000+ posts) Send PM | Profile | Ignore Tue Apr-25-06 11:43 AM
Response to Reply #9
10. Canon wants me to send it back
for evaluation. :cry: I think I'm just going to live with it for a while and maybe take it in to somebody local to see if they have any ideas. I'm really unenthused about not having it here, especially when we're planning a trip next month. They say they'd have it back in 10-14 days, but I doubt it.
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