# Canon's unsuccessful sensor cleaning on a 5D Mark IV



## notapro (Sep 15, 2017)

Hello, Everyone.

I received my 5D Mark IV today from a Canon factory service repair center (New Jersey).

I sent it in to have the sensor cleaned.

Attached is an image of how things turned out.

Mightly disappointed, I must say.

Canon is taking it back to give things another go. I'm going to print an image of the photo and include it in the box. Maybe it will help the Canon person know what to do differently.

Anyone have this sort of thing happen?


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## YuengLinger (Sep 15, 2017)

I'd be unhappy, but if it involved sending back and forth by mail I might ask for a credit or refund and just clean it myself at home.

Do you, by any chance, have a shot of how it looked BEFORE the cleaning?


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## notapro (Sep 15, 2017)

Hello, YuengLinger.

I don't have a shot of the sensor before I sent it to Canon. There were a few spots (around 5-7) at the top of the frame, which I'm guessing would be at the bottom of the sensor.

I have a 5D Mark III I can use while the newer body is out of service, so I'll go with sending the Mark IV to Canon as many times as they'll take it. They're paying the shipping and handling on the return.

The last time this happened was with a Rebel T3i (my first camera). I purchased it from a "big box" retailer, and after the second unsuccessful sensor cleaning by their lab (who knows what or where the lab was), they replaced the camera. That first Rebel had around 20 dust spots that would appear at f/13 (I was photographing airplanes).

I've cleaned successfully the sensor on my Mark III, but I wanted to avoid the potential frustration of another sensor cleaning, especially since Canon (US) only charges $64.44 (including shipping and hanlding) for a "7-point Image Sensor Cleaning".

I'm hopeful, but not optimistic, about what Canon will do the second time around. On the Mark III, one camera shop said the sensor was clean, despite my showing them an image with the multiple spots visible in the frame. Another camera shop was going to clean the sensor, but stopped, saying there was nothing to clean. They said my photograph/image of the dirty sensor wasn't accurate and that maybe the spots were from something other than the sensor.

I was annoyed, so I purchased stuff and cleaned it myself. A bit frustrating due to the learning curve, but it ended well.

For now, I'll hope for the best.


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## Ryananthony (Sep 15, 2017)

I couldn't imagine sending one of my cameras to canon every time I wanted the sensor cleaned.


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## niels123 (Sep 15, 2017)

That looks not good! Some years ago, I had my 5D III sensor's damaged due to the shutter making contact with it when it moved. This was a factory error that affected a small percentage of camera's and the sensor was replaced under warranty. These horizontal 'stripes' on my damaged sensor look quite familiar to what I see on your sample pic :-\


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## tpatana (Sep 15, 2017)

I'm happy I learned to clean with my Rebel, so now I'm not afraid to clean my 5D4 or 1DX.


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## cpsico (Sep 16, 2017)

What was it cleaned with a sand blaster?


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## Valvebounce (Sep 16, 2017)

Hi cpsico. 
Nah, that's not sand blasted, that would be a more uniform matt finish, that looks more like the old engineers favourite, the oily rag! 
Seriously though, that is disgraceful! If I received that I'd be getting a refund on the cost and carriage and doing it myself, much like tpatana I'm happy I learned to clean on my 300D, now I'm not afraid to clean my 7D's or 1DsIII. 

Cheers, Graham. 



cpsico said:


> What was it cleaned with a sand blaster?


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## Mt Spokane Photography (Sep 16, 2017)

canon does not wet clean sensors, they use a dry method. That looks like it might be oil or grease, but where did it come from?

They will send a return shipping label, just call or email.


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## notapro (Sep 16, 2017)

Canon has agreed to take the camera back and perform a cleaning service again. Canon is also paying the shipping costs.

I certainly hope for a better result. Is it true that Canon does only a dry cleaning of their sensors?

If I end up going for a wet cleaning on my own, I plan to use Visible Dust swabs (green) and Dust Patrol's Gamma Optical Cleaning Fluid.

For those who wish to share how many swabs they use for a wet cleaning to get their sensors fully clean, I'd be curious to know your number. I went through five to get my 5D Mark III clean, but the first time I tried a wet cleaning, I used around 15 swabs. It was a bit of a learning curve for me.

Incidentally, the attached photo for this post was taken at f/22. In the past, I used f/32, but I'll be all right with a sensor that looks clean at f/22.


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## Talys (Sep 16, 2017)

notapro said:


> Canon has agreed to take the camera back and perform a cleaning service again. Canon is also paying the shipping costs.
> 
> I certainly hope for a better result. Is it true that Canon does only a dry cleaning of their sensors?
> 
> ...



I'd just take it to a local shop to have it cleaned, if you're not comfortable with doing it yourself.

Cleaning the sensor is very easy to do though. I have never used anything close to 15 swabs. More like... 2, and a grabby stick? But my sensors don't look anything like yours, either. That looks like it's been dragged through a swamp. I guess.. what on earth is on that sensor? I can only assume that it's not dust, because the horizontal line -- well, I just can't see how dust would smear like that.

Second, maybe I'm wrong, but it doesn't matter whether you use f/22 or f/32 (just expose it for longer at f/32). The way I test mine -- and if there's a better way, please do tell -- I set it to max aperture, set the shutter to a couple of seconds (long enough to get a white exposure on a white target), point a constant light at something big and white, and then press the shutter and swirl the camera around.

Where there's dust, there should be no light shining through, ergo dark spot. It doesn't really matter if the white target is dirty, because the camera is moving around (and not in focus anyhow).


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## notapro (Sep 16, 2017)

Hi, Talys.

I've not had much luck with camera shops. They've told me dirty sensors were clean (two different shops). I've had estimates from other places of up to $100.

That's why I cleaned my T3i and 5D Mark III. At just under $65 for Canon to do the service, I thought I'd try it out for the 5D Mark IV. I'll shoot at f/8 to f/20 with some frequency, so having a sensor with no spots at smaller apertures is important for me. I can use the Mark III in the meantime.

For those of you who do your own cleaning, you're getting a fully clean sensor at f/22 or smaller aperture?


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## [email protected] (Sep 16, 2017)

notapro said:


> For those of you who do your own cleaning, you're getting a fully clean sensor at f/22 or smaller aperture?



I think I have good days and bad days in cleaning sensors. On a good day, it's a one or two swab affair. Last week i wasted maybe 8. I'd put too much fluid on the swab, and I wound up with droplets. Interestingly, the pattern of the droplets dragged across the shutter by the next swab made a result that looks very much like yours.

I should add an eye dropper to my cleaning kit to make sure I get just the right amount of fluid on the swab. 

I might waste a few swabs, but I always get it so that I can see no dust in subsequent tests.


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## pwp (Sep 16, 2017)

I'm lucky that my studio is 15 minutes drive from our local CPS. They offer over the counter while you wait sensor cleans for members. I've had bodies back in my hands in my hands as quick as three minutes. Since my first digital body, the original 1Ds, every sensor clean has been perfect. It's probably been three or four years since I've needed a sensor clean, something I attribute to the sensor clean technology in the newer bodies, and increased care with lens changes. Windy dusty environments are an obvious no-no, and making the change as quick as practical must help. If I know I have a job in a dirty location like an oil refinery or a mine, I'll take three bodies, one with 16-35, one with 24-70 and one with 70-200. No lens changes required!

-pw


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## niels123 (Sep 16, 2017)

In The Netherlands we have a company called Chipclean. They only clean sensors (and occasionally do some AFMA); they do an excellent job and use some secret method that makes the sensor anti-static to dust, so it stays clean much longer compared to when Canon cleans it.


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## Jopa (Sep 16, 2017)

cpsico said:


> What was it cleaned with a sand blaster?



Pressure washer with some soap most likely.

I bet it's not that funny for the owner though


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## sanj (Sep 16, 2017)

This is bad.
I have gotten my sensor cleaned about 10 times on various cameras (before every big trip) but can't trust the cleanliness. 
Canon is wonderful at service generally but cleaning is something I do not trust them with. Sad.


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## GammyKnee (Sep 16, 2017)

I've never used a sensor brush, but I imagine if you used a dirty brush (especially one that had caught some oil), that's what it might produce. Shameful job by the service center.

Up to this point I've used the roll-your-own swab method (reusable sensor wand plus pec pad). Sometimes I get a lovely clean result fast, but sometimes I go for swab after swab, always having just one more spec to clean up. 

I've now got one of those Eyelead gel cleaning sticks; I haven't had to use it yet (little bit cautious), but my plan is is that if a wet clean is perfect apart from one annoying spec in a bad place I can just mop it up with the stick.


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## weixing (Sep 16, 2017)

Hi,


notapro said:


> I certainly hope for a better result. Is it true that Canon does only a dry cleaning of their sensors?


 Canon service center in my country once told me that they don't do contact cleaning... they only use air to clean.

Have a nice day.


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## tpatana (Sep 16, 2017)

Jopa said:


> cpsico said:
> 
> 
> > What was it cleaned with a sand blaster?
> ...



They saw these tutorial: https://www.youtube.com/watch?v=lrdkFXsr5Us


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## DavidR (Sep 16, 2017)

Dear all
Today I cleaned the sensors on my two 5D2 cameras. I had originally thought they were both pretty clean but I discovered a large number (c.30) spots on one sensor whilst editing in Lightroom. The reason I discovered the spots was that I used the Prolost dehaze plug-in for the first time and when I set it to 100% the spots appeared!
So today I used the dehaze feature to check my cleaning and it proved a marvellous help in checking where the spots were and whether I had got rid of them.


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## Mt Spokane Photography (Sep 16, 2017)

notapro said:


> Canon has agreed to take the camera back and perform a cleaning service again. Canon is also paying the shipping costs.
> 
> I certainly hope for a better result. Is it true that Canon does only a dry cleaning of their sensors?
> 
> ...



If there is oil or some material that requires a wet cleaning, they will do it, but they do not wet clean a sensor by default. Something definitely smeared on the sensor, dust particles don't do that, so oil or a botched wet cleaning.

I do wet clean my sensors as a last resort, I never had to wet clean my 5D MK III, but did my MK II a few times. My Rocket blower took care of the MK III. I have not noticed any issue with my MK IV or SL2, but I'm pretty tolerant of a few dust particles as long as hey are not gross.


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## Jopa (Sep 17, 2017)

tpatana said:


> Jopa said:
> 
> 
> > cpsico said:
> ...



This is nuts!!! ;D


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## Talys (Sep 17, 2017)

notapro said:


> Hi, Talys.
> 
> I've not had much luck with camera shops. They've told me dirty sensors were clean (two different shops). I've had estimates from other places of up to $100.
> 
> ...



Holy smokes. That's insane! 

Locally here, there's one store that has a frequent shopper thing, and every 10th visit or something, they'll give you a free sensor cleaning. Not that I've ever tried it; I just do it myself.

But -- there should be no difference between f/22 or f/32. Dust is dust, and it will block light from reaching the sensor, whether you're shooting at f/1.4 or f/32. Because it's right on the sensor, there's no depth of field or focus issue. It's actually blocking light from reaching the sensor, and therefore, assuming noise reduction, antialiasing and all that is turned off, the raw data should have clear dark spots.

The only reason you want to set it to a small aperture is so that you can increase the shutter speed to a very slow shutter speed (you could use an ND filter instead). The only reason you want a very slow shutter speed is so that you can move the camera around, so that you're not photographing (recording) imperfections in your drywall, cardboard, white backdrop, or whatever you're using.

A sensor loupe (or some other magnifier) might be helpful in diagnosis.

Not that I'm an expert in this, so if I'm wrong, someone please correct me


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## SecureGSM (Sep 17, 2017)

Hi Talys,

Dust cannot be detected when shooting with F1.4 apertures. 
You need to stop down to F11 at least to see the dust clearly. That's due to physics of light and how it moves around avoiding obstacles. Ideally you would like to stop down and use long exposure while pointing at a white wall and giving your camera a circular motion handheld to blur background features. 




Talys said:


> But -- there should be no difference between f/22 or f/32. Dust is dust, and it will block light from reaching the sensor, whether you're shooting at f/1.4 or f/32. Because it's right on the sensor, there's no depth of field or focus issue. It's actually blocking light from reaching the sensor, and therefore, assuming noise reduction, antialiasing and all that is turned off, the raw data should have clear dark spots.
> 
> The only reason you want to set it to a small aperture is so that you can increase the shutter speed to a very slow shutter speed (you could use an ND filter instead). The only reason you want a very slow shutter speed is so that you can move the camera around, so that you're not photographing (recording) imperfections in your drywall, cardboard, white backdrop, or whatever you're using.
> 
> Not that I'm an expert in this, so if I'm wrong, someone please correct me


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## pwp (Sep 17, 2017)

Here's the perfect sensor clean instruction video:
https://www.youtube.com/watch?v=lrdkFXsr5Us
The results would deliver a perfectly clean sensor every time.

-pw


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## Talys (Sep 17, 2017)

SecureGSM said:


> Hi Talys,
> 
> Dust cannot be detected when shooting with F1.4 apertures.
> You need to stop down to F11 at least to see the dust clearly. That's due to physics of light and how it moves around avoiding obstacles. Ideally you would like to stop down and use long exposure while pointing at a white wall and giving your camera a circular motion handheld to blur background features.



Interesting. That's exactly what I do, but I was unaware that it was undetectable at wide apertures. I've never tried it, because you need the smaller aperture to give yourself time to do the circular motion that you describe. Usually, I just set it to f/22, 2 seconds -- or thereabouts.


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## notapro (Oct 6, 2017)

If anyone is still interested or curious, this is the sensor after it's second visit to Canon's repair center (this time it was sent to the Virginia location).

I'm glad to have a Mark III to use while the Mark IV is out of service.

I took another photo which shows some degree of improvement over the previous cleaning. Canon requested this image so that their technicians can use it to guide them in the sensor's third cleaning.

Canon is paying for shipping both ways and has not charged anything additional.


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## Mt Spokane Photography (Oct 6, 2017)

Wow, Canon needs to do a wet cleaning, the dirt looks baked on. A lot of the smears are still there. Canon does not need the photo to guide them, they should be taking their own, before and after until its clean.


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## ejenner (Oct 15, 2017)

After 10 goes you might get a new camera. 

I've always cleaned my own. But I have had to get less anal about getting absolutely everything off. 



notapro said:


> For those of you who do your own cleaning, you're getting a fully clean sensor at f/22 or smaller aperture?



I used to try and it drove me nuts, now I no longer aim for a 100% clean sensor at f22. If I have 2-3 small and light spots visible at f22, then I call it good. Those will generally be very light at f16 and if they are in the sky I just heal in PS. I always check my images anyway as you never know when you might get a spot, even if it was perfectly clean before shooting.

Since using the gel pen I have found it much easier to get to something which is really not going to show up at f16.

I think some people, even shooting landscapes at f16, can get a little too anal about the odd light spot (the OP's sensor is IMO 'trash' right now though).


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## Ryananthony (Oct 15, 2017)

Just clean the sensor yourself. How long is your camera going to be out of commission for something that will take you 5 minutes at home.


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## ejenner (Oct 15, 2017)

Talys said:


> But -- there should be no difference between f/22 or f/32. Dust is dust, and it will block light from reaching the sensor, whether you're shooting at f/1.4 or f/32. Because it's right on the sensor, there's no depth of field or focus issue. It's actually blocking light from reaching the sensor, and therefore, assuming noise reduction, antialiasing and all that is turned off, the raw data should have clear dark spots.



This would be the case IF the dust was 'right on the sensor', but it isn't. You have a couple of mm of glass between the surface the dust is on and the actual sensor pixels. 

Just in case you are interested:

https://wordpress.lensrentals.com/blog/2014/06/sensor-stack-thickness-when-does-it-matter/


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## Mt Spokane Photography (Oct 15, 2017)

ejenner said:


> Talys said:
> 
> 
> > But -- there should be no difference between f/22 or f/32. Dust is dust, and it will block light from reaching the sensor, whether you're shooting at f/1.4 or f/32. Because it's right on the sensor, there's no depth of field or focus issue. It's actually blocking light from reaching the sensor, and therefore, assuming noise reduction, antialiasing and all that is turned off, the raw data should have clear dark spots.
> ...



Yes, its been well established since the first DSLR's that dust on the sensor assembly can be seen best by lighting it thru a small aperture of the lens. That creates more distinct shadows from the smears and dust particles.


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## notapro (Oct 21, 2017)

I received my camera today, back from its third trip to Canon.

The "service details" section on the note from Canon says that the sensor was ". . . scratched and had dust on it. The CMOS assembly was replaced".

I am curious as to whether it was felt that a cleaning would not have removed the dust. I didn't notice any obvious scratches in the photos I posted previously in this thread. It's nice that Canon replaced the CMOS assembly and that they did so as a courtesy.

The new sensor (glass above it) isn't perfect, but it's good enough for now. The attached image shows some of the dust spots underlined by white lines. The image was taken at f/22, ISO 100, 2.5 seconds (manual focus, with the focus set at "infinity"). After pulling the RAW image into Photoshop, "Auto contrast" was performed, and I drew in the white underlines.

I took a couple of "regular" photos (not of the sort I'd use to check for dust) of my place (indoors) at f/22 and f/16. Only a couple of spots were visible with relatively careful inspection. They're the sort of spots that one might see in a photo of a clear blue sky, easily removed in post-processing. In practice, then, I'm fine with the sensor as it is currently.

I've cleaned sensors myself (as Ryananthony suggests in this thread), but given the $64.44 price (including shipping) for Canon to do the cleaning, I was curious about how things would turn out. I have a 5D Mark III, so being without the Mark IV for a while wasn't burdensome.

I credit Canon for taking action to help me with my camera, especially since I'm just a regular user, not someone who uses their professional services (CPS).


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## Mt Spokane Photography (Oct 21, 2017)

All sensors have dust, a few seconds after cleaning, it settles almost immediately. Dust in the air is rated in millions of particles per cubic meter, even super clean rooms have some dust.

So, with a sensor, its more about objectionable dust, large particles in excessive numbers. The tiny particles are too small to be seen, but if there is oil or lube on the sensor, they collect into a nasty mess.

The dirt smeared on the sensor and the scratches look like they were caused by the dry cleaning technique. I had thought that amount of dirt was a thing of the past, which makes me wonder if it was a mixture of dust and lube.


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## ejenner (Oct 28, 2017)

Nice that they realize they completely f**ked up the sensor. I guess not quite the 10 goes I predicted, 3 and a new sensor.

Yea, I've meticulously cleaned a sensor, then one shutter cycle and you have 3 new spots. You can keep doing that forever if you use your camera in less than perfect weather.


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## YuengLinger (Oct 28, 2017)

Happy ending! Thanks for following up to let us know Canon treated you right after the back and forth.


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