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View Full Version : help! Is this dust or lubrication/oil on my image sensor?



alexsommers
08-11-2009, 02:29 AM
I was hoping I could ask for some of your opinions on this matter.


I have a Canon Rebel XSi and I fear that I might have oil/lubrication on my image sensor. I bought a rocket blower the other day to see if I could blow off the dust and also ran the sensor cleaning function on the camera multiple times but it appears that none of the spots were removed.


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I fear that if it is oil that my sensor will need wet cleaning and I'm not confident in my ability. I live in the Phoenix area and Tempe Camera cleans sensor's for $35 and it's overnight. Should I just have them do it? And if so, anyone in the Phx area have experience with Tempe Camera?


Thanks in advance for everyone's opinions and thoughts.

IAMB
08-11-2009, 03:20 AM
Yup, you've got oil spots (at least the ones with a rainbow halo around the dark spot are oil... I see the same thing with microscopes that haven't been cleaned properly by students). Anyway, you should try the sensor cleaning version of the LensPen (here ("http://www.bhphotovideo.com/bnh/controller/home?O=&Q=&IC=LESK1&A=RetrieveSku)) before taking it in. I've used that particular LensPen exclusively for quite a while and it works quite well for most applications. If that doesn't work, then you'll need a wet cleaning. If that still doesn't work, you could always try cleaning solution for the oil lens on a microscope (any college biology lab would probably just give you some if you asked nicely)... though I'm not sure how well it would work on a camera sensor.

Oren
08-11-2009, 09:08 AM
IAMB, how do you know it's oil? I'm sorry but I disagree, it looks like normal dust to me. Anyhow, with the given info - i.e you have no idea how the picture was taken and what kind of PP was done, you can't really tell anything for sure.

piiooo
08-11-2009, 09:56 AM
No matter what this is, if you get a decent sensor cleaning kit and perform wet cleaning you should be able to get rid of this stuff.

Oren
08-11-2009, 10:06 AM
More importantly - if your pictures look fine, you shouldn't do anything... if it's ain't broke, don't fix it.

Chuck Lee
08-11-2009, 10:39 AM
Alex,


Welcome to the forum.


I apologize up front for these stupid questions. I do not know your level of expertise.


1) Did you doa "mirror up" function before using the rocket blower?


2) If so, did you hold the camera body with the lens mount facing down as you blew it off?


3) Also, are you seeing alot of dust/hairs/fuzz on the focusing screen through the viewfinder?


I'm asking because if this is dust, you should see a big difference after using the blower. The oil spotting I've seen shown on the 1D MkIII was never this pronounced andI didn't see a service bulletin for the XSi. Only the 1D and 1Ds MkIII.


Looks like dust to me.

alexsommers
08-11-2009, 12:27 PM
thanks for the replies so far. Just to give a little more back ground info:


I took this pic at f22 on a white sheet of paper and processed it in photoshop to increase contrast and tone to have the spots show up.


Chuck,


no worries for the questions.


1. I did have the mirror up when I used the blower.


2. I also did hold the camera body facing down in hopes that the dust would fall out of the camera once blown off


3. I'm not really noticing anything through the viewfinder but I'm at work now so I can't check my camera.


when I used the blower, I only had the tip barely into the camera body as I didn't want to risk touching anything inadvertently when blowing. Maybe I should blow closer to the sensor then?

Oren
08-11-2009, 12:36 PM
I'm asking because if this is dust, you should see a big difference after using the blower.
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Again I disagree, especially after he said that he "had the tip barely into the camera body" - I also took similar pictures to this - white sheet at f/32 (btw if you can, use higher f number than f/22) and increased contrast. I also had the tip barely into the camera for the same reason and I tried few times but all the spots remained at the same place - the blower did nothing.


Maybe I should mention though that I didn't use a specific blower for the task but some blower that I had around which originally came with some balloons that I bought many many years ago and it doesn't blow much air - maybe it's too weak.

EdN
08-11-2009, 01:36 PM
The spots look exactly like the dust I got on my 5D. I used a rocket blower to blast it out regularly and it worked great.


Here's what I did: Tipped the camera down for dust particles to fall out when dislodged. Put camera on Bulb. Press shutter. Vigorously blast out inside of camera with rocket blower. Place nozzle of blower as close as you dare to the sensor and blast away. Release shutter to drop down mirror and clean that off as well as the top of the pentaprism. Press shutter again and blast off sensor surface again. Repeat as long as desired.


After several minutes of this, there was a noticeable difference in reduction of spots.


I even purchased "Eclipse" brand sensor cleaning fluid and swabs for further cleaning but never had to use them because the rocket blower was so effective. The Eclipse fluid cost $13.49 and 3 swabs cost $14.95 so your camera store offers a reasonable deal for sensor cleaning. I've never had to "swab" my sensor but several websites I remember seeing say that it isn't that difficult to do. Just have to be careful when doing it. So do you trust yourself or your camera store?

Chuck Lee
08-11-2009, 02:36 PM
Vigorously blast out inside of camera with rocket blower.


That's why I asked #3. Do you see dust and fuzz in the viewfinder? This is the result I usually get after a good blasting of the LPF inside of my cameras. Erks the crap out of me but I'd rather have dust in the viewfinder than dust on f8- f13landscape shots.


EdN, Is the result that you get after a "Vigorous" blasting?


I want to raise caution though when using EdN's method of holding the mirror up. You have to keep the shutter button depressed which can be awkward. One slip and you may find the mirror clamping the end of your blower to the surface of the LPF. That's why I always use the cleaning function and do a mirror up. It frees me from having to hold the body any particular way.


I always inspect the surface of the LPF under a desk lamp during the cleaning process. You can usually see the dust specs. I hold the camera up and vigorously blow with a bulb blower. Usually it's several hard "squirts" of air. I then look at the surface of the LPS to see if the dust is gone or migrated. Most of the time I can get it clean enough using this visual inspection method. Can't say I have to hold the tip of the blower very far inside of the lens mount opening. I'd rather not take the chance of hitting the LPF.


My 5D was used when I bought it and I have a sinking feeling that the guy who owned it was a clean freek. Looks like I've got a smear on the sensor that shows up around f8 plus. I've entertained the idea of purchasing a wet system to see if I can get rid of it. It looks like a patch of dust thats fused on the LPF. I'm wondering if he used a wet system on it often.

IAMB
08-11-2009, 02:38 PM
IAMB, how do you know it's oil? I'm sorry but I disagree, it looks like normal dust to me. Anyhow, with the given info - i.e you have no idea how the picture was taken and what kind of PP was done, you can't really tell anything for sure.
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The main reason I call some of the spots (not all of them) oil is the refraction around the borders of the spots. If you look closely, you'll see a rainbow halo around a number of the spots. It takes a fairly extraordinary set of circumstances to see haloes like the ones I'm seeing if it's just dust.





The other reason is experience. As a microbiologist, I've seen oil spots on more optics than I care to think about, and these look exactly like what I'm used to seeing with oil spots and looks nothing like what I see when I have dust on my camera sensors.





I am, however, perfectly open to the possibility of being completely wrong.

Sinh Nhut Nguyen
08-11-2009, 04:46 PM
Sensor dust is a fact of life for us DSLR shooters [:)], you'd see it if you look for it and you're really asking for it when you shoot a white paper @ f/22 and increase contrast/tone in photoshop. Shoot normal subject at f/8 and wider and I bet you 90% of the dust spots will disappear. You won't see the dust spots in theshadow area, if you see stubborn spots in lighter area like blue sky, just clone them out in PS or use the Dust Delete Data that comes with DPP.


My question for you is...


Do you always shoot a white paper @ f/22 then increase contrast and tone in Photoshop?


Don't worry about sensor dust....and welcome to the forum.

alexsommers
08-21-2009, 01:21 AM
Thanks again to everyone for your thoughts and input. Although it is rather uncommon for me to shoot at f22, I decided to get a lenspen sensorklear to remove as much of those dust particles as I could. For those of you who may be interested in seeing the results, here you go. Still not completely clean but I didn't expect it to be. At least it is better/cfs-file.ashx/__key/CommunityServer.Components.UserFiles/00.00.00.28.80/IMG_5F00_5629ab.jpg

Stephen Probert
08-21-2009, 02:01 AM
Hey Alex, I am glad you got your sensor clean. I still think it was oil since the specs are so uniform. The dust I get on my 5d is not that uniform. In addition, I have no trouble with my XTi which also has the dust sonic vibrator that the XSi has. Since the sensor vibrator and rocket blower didn't work, oil it is, I say, or some other liquid from outside the camera.

Julius
09-15-2009, 08:24 PM
The little specks are definitely dust....should be relatively easy to clean with a blower. If that doesn't work, then you can wet clean the sensor. There are a lot of posts on how to do this.