# Why the locked thread? Only wanted to follow up.



## Gas am (Jan 18, 2014)

Why was my last thread locked? I only wanted to post a possitive on canons reaction to my eos problems.


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## Mt Spokane Photography (Jan 18, 2014)

It was probably attracting too many objectionable comments and causing the mods too much work controlling them.


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## Don Haines (Jan 18, 2014)

Mt Spokane Photography said:


> It was probably attracting too many objectionable comments and causing the mods too much work controlling them.


I'm curious why it was locked too.... I didn't see any bad language or insults, and I think it is a good idea to talk about how the manufacturing defects (stuck pixels) are dealt with. It was an informative topic. Perhaps there were a few posts that were objectionable and deleted (I don't know.... just guessing), but if that was the case it is a pity that a few bad eggs ruined a good discussion.


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## Gas am (Jan 20, 2014)

Canon UK replied to my email concerning dead pixels.
'In reference to your email I understand you were received 2 EOS 700D which had a dead pixel using a long exposure. If it is the LCD screen which has a dead pixel that could indeed be the case. Allthough the lcd monitor is precise manufactured there may be a few dead pixels.

If you have imported the images onto your computer and they are showing dead pixels then the camera needs to be send in for service.

Once again, thank you for contacting Canon. We trust this information is of use to you. Should you have any further questions, please do not hesitate to contact again.'

I guess the guy was not a UK rep, as his reply was a little bit awkward. But he clearly says send in the camera if I am seeing dead pixels. 

I have had 4 700d bodies. All 4 have had pixel issues. My previous 1000d and 600d were fine. So my conclusion is that canon are shipping dodgy sensors or I am very unlucky.


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## Mt Spokane Photography (Jan 20, 2014)

Gas am said:


> Canon UK replied to my email concerning dead pixels.
> 'In reference to your email I understand you were received 2 EOS 700D which had a dead pixel using a long exposure. If it is the LCD screen which has a dead pixel that could indeed be the case. Allthough the lcd monitor is precise manufactured there may be a few dead pixels.
> 
> If you have imported the images onto your computer and they are showing dead pixels then the camera needs to be send in for service.
> ...


Are you sure they are Dead pixels (Black).
There are Stuck pixels (Red all the time), Dead pixels (Black), and Hot pixels which can only be seen after a long exposure, and are normal. 
If you post a image, perhaps someone can help, but right now, it sounds like you are not defining the issue correctly.
http://photographylife.com/dead-vs-stuck-vs-hot-pixels


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## jrista (Jan 20, 2014)

I called bull on the last topic, after Gas am claimed Amazon had exchanged four copies of the same camera four times without question, and due to the lack of any sample images to back up the claims of problematic pixels. After that, it was locked. 

I still don't think the discussion here can proceed without getting some visual evidence to clearly explain what the OP is talking about. I highly suspect Gas am is complaining about the very well known, expected phenomena of hot pixels that occur during longer exposures. However, without any kind of visual evidence, it is hard to say that for sure.

So, Gas am, PLEASE...post some sample 100% crops demonstrating the problem. We can't really help you without knowing exactly what it is you are talking about.


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## Quasimodo (Jan 20, 2014)

Mt Spokane Photography said:


> Gas am said:
> 
> 
> > Canon UK replied to my email concerning dead pixels.
> ...



Thanks for the link. Very informative.


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## GMCPhotographics (Jan 20, 2014)

Gas am said:


> Canon UK replied to my email concerning dead pixels.
> 'In reference to your email I understand you were received 2 EOS 700D which had a dead pixel using a long exposure. If it is the LCD screen which has a dead pixel that could indeed be the case. Allthough the lcd monitor is precise manufactured there may be a few dead pixels.
> 
> If you have imported the images onto your computer and they are showing dead pixels then the camera needs to be send in for service.
> ...



There's quite a lattitude for sensor QA, I've had cameras with or without dead pixels over the years. It's a little bit like lenses...try before you buy. There's always a small difference between every lens and camera. 
I have apair of 5DIII's and one has a few long exposure dead pixels...it's happens and it's really no biggie.


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## Lichtgestalt (Jan 20, 2014)

jrista said:


> I called bull on the last topic, after Gas am claimed Amazon had exchanged four copies of the same camera four times without question



well have you any experience with amazon to think that?

i bought 6 monitors over the last few month, tested them for a week and send them back.
amazon did not ask questions and i got my money back after 3-4 days.

amazon never asked me any questions, and i send stuff back regulary.
as long as you buy stuff too you will not be on a blacklist either.

when your ratio "ordered" vs. "send back" is too high you might get an email.
but then you really have to be abusing it.
but 4 times.. nah.


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## Gas am (Jan 20, 2014)

This is one example at 100%. The other problem pixels were red or blue. 
Thanks for killing my first thread btw. This will be my last.
Cheers for all the genuine help


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## jrista (Jan 20, 2014)

Gas am said:


> This is one example at 100%. The other problem pixels were red or blue.
> Thanks for killing my first thread btw. This will be my last.
> Cheers for all the genuine help



You were repeatedly asked for sample images, not just from me, and you kept ignoring it. When someone repeatedly refuses to provide visual evidence when asked, you can't help but get suspicious. 

As for the image below, is it safe to assume that the X marks the spot where a hot pixel might be? If all you have is ONE hot pixel, you have absolutely nothing to complain about. Your image is a hell of a lot cleaner than most are during long exposures, as most result in dozens of hot pixels across the frame, of a whole variety of colors. Even if the entire x is "hot", that is incredibly easy to correct, and even permanently clean with the camera itself by mapping dust and spots. I don't think you have a problem...hot pixels are a fact of life with digital sensors at high ISO and/or long exposure.

I also encourage you to use Adobe Lightroom to process the RAW. LR deals with hot pixels very well...it is entirely possible the problem you are experiencing will simply disappear when demosaiced with LR.


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## Gas am (Jan 20, 2014)

The x is the in every long exposure. It is not me marking the spot. It's a cluster of dodgy pixels. I did not repeatedly ignore requests. I just didn't have the camera or images to hand. I am telling the truth when I said that amazon had no problems in sending me 4 bodies. Do you doubt me? And if so, why? Canon have advised that I send them the body with faulty pixels. I have had 4 with faulty pixels.

Your attitude towards me is curious. I came here for help and instead got silenced......... 
It seems that its not just me though, a quick google search revealed other silenced would be contributors to your forum. 

I can't understand you having an open forum if you feel the need to berate and silence contributors.


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## Gas am (Jan 20, 2014)

Please close this thread and delete my acc. It's wasting my time and for some reason making you suspicious.......

Oh btw plz stop smoking that stuff it's making you paranoid


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## Quasimodo (Jan 20, 2014)

Gas am said:


> Please close this thread and delete my acc. It's wasting my time and for some reason making you suspicious.......
> 
> Oh btw plz stop smoking that stuff it's making you paranoid



And I thought the message before the last two was your last? The This is my last post argument; only works if you are actually able to pull it off  

Btw: I thought it was sad that you wanted to leave this community because your last thread was pulled, a society which on my part has learned me so much, but hey...?


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## jrista (Jan 20, 2014)

Gas am said:


> The x is the in every long exposure. It is not me marking the spot. It's a cluster of dodgy pixels. I did not repeatedly ignore requests. I just didn't have the camera or images to hand. I am telling the truth when I said that amazon had no problems in sending me 4 bodies. Do you doubt me? And if so, why? Canon have advised that I send them the body with faulty pixels. I have had 4 with faulty pixels.
> 
> Your attitude towards me is curious. I came here for help and instead got silenced.........
> It seems that its not just me though, a quick google search revealed other silenced would be contributors to your forum.
> ...



I see your using an iPad app of some kind, and I'm wondering if that may be part of the problem. It would be highly unusual for multiple cameras to exhibit the exact same problem like that, exceptionally unusual, so there is probably another explanation. An x is an unusual formation. I'd be curious to see how the image renders if you used ACR+PS or LR.

BTW, I wasn't trying to get your thread shut down. Visual evidence, and a more active feedback loop with you actually providing some visual information and possibly trying some of our recommendations would have been far more conducive to solving your problem. And, sorry to be HONEST, but yeah, I think returning your camera FOUR times in a row over a tiny area of pixels is a little extreme. To be quite frank, I don't really believe it, but again...further investigation, with you providing visual information along the way, would have helped us zero in on the problem and solve it without requiring multiple returns and all that wasted time or money. 

As for paranoid...your the one who claims you returned _multiple_ cameras _on a dime_ after freaking out over a small cluster of hot pixels (something ridiculously easy to map out and permanently eliminate)...and on an iPad app, of all things. Just sayin...  :


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## Don Haines (Jan 20, 2014)

Gas am said:


> This is one example at 100%. The other problem pixels were red or blue.
> Thanks for killing my first thread btw. This will be my last.
> Cheers for all the genuine help


So if I understand correctly, in every exposure you have a group of pixels making a tiny "x"?
and this same thing has happened on multiple cameras?

That really sounds weird!

What settings are you shooting at? Are you shooting in RAW? Could you try again and post the RAW file?

The "x" pattern is very suspicious.... it is unlikely that a sensor would fail like that... it could be something introduced in processing. If someone else can replicate this using your RAW file it may help to pin things down.


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## Skulker (Jan 20, 2014)

Gas am said:


> This is one example at 100%. The other problem pixels were red or blue.
> Thanks for killing my first thread btw. This will be my last.
> Cheers for all the genuine help



That's a screen grab rather than a copy of the problem image. Somehow this seems strange. The OP sounds upset at several people being rather suspicious. Maybe he really is not getting peoples reasoning and so not understanding. It would have been good to see an image straight from a raw converter like LR or DPP.


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## Gas am (Jan 21, 2014)

I set the camera for 25 sec exposure and on each shot I saw the same cluster appear. The shots were jpeg only not raw. The middle pixel is off white and the edge pixels are slightly darker, forming the x. I posted the screen grab from the iPad as it was the quickest way for me to send an example at the time. It looks the same on my PC monitor. A very obvious x. This was the worst of the bodies and has been returned to amazon. Three of the four cameras I received had red and blue and white pixels clearly visible at 100% on long exposures. So this seems to back up your point that all digital long exposure have these issues. I am sorry for not posting examples immediately as I was taking advice from canon and amazon and various other places. At one point I had four new cameras on my table at home. One was wet from dodgy couriers and the three others had various hot/stuck pixels at long exposures. 

I have no reason to lie or misinform anyone on this forum. I just wanted opinions on an issue. Clearly my opening thread was ill conceived. I loved my previous two eos cameras. And have just bought a new L 2.8 200mm prime lens. So was concerned to see so many bad pixels on a new body. I am sorry to have been too vague or slow in posting samples. 
Happy shooting


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## Don Haines (Jan 21, 2014)

Gas am said:


> I set the camera for 25 sec exposure and on each shot I saw the same cluster appear. The shots were jpeg only not raw. The middle pixel is off white and the edge pixels are slightly darker, forming the x. I posted the screen grab from the iPad as it was the quickest way for me to send an example at the time. It looks the same on my PC monitor. A very obvious x. This was the worst of the bodies and has been returned to amazon. Three of the four cameras I received had red and blue and white pixels clearly visible at 100% on long exposures. So this seems to back up your point that all digital long exposure have these issues. I am sorry for not posting examples immediately as I was taking advice from canon and amazon and various other places. At one point I had four new cameras on my table at home. One was wet from dodgy couriers and the three others had various hot/stuck pixels at long exposures.
> 
> I have no reason to lie or misinform anyone on this forum. I just wanted opinions on an issue. Clearly my opening thread was ill conceived. I loved my previous two eos cameras. And have just bought a new L 2.8 200mm prime lens. So was concerned to see so many bad pixels on a new body. I am sorry to have been too vague or slow in posting samples.
> Happy shooting


I'm wondering if the "x" was made by the in-camera software from a single bad pixel, possibly as part of the long exposure noise compensation....

If you change the strength of the noise reduction, does it change the "x" any? If you shoot RAW, does the "x" turn into a single pixel?


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## 9VIII (Jan 21, 2014)

The "X" is perfectly normal, that's just how the demosaicing software interprets it when a green pixel goes. In DPP when first loading a picture they start out as green dots and then turn into the little x's.


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## jrista (Jan 21, 2014)

9VIII said:


> The "X" is perfectly normal, that's just how the demosaicing software interprets it when a green pixel goes. In DPP when first loading a picture they start out as green dots and then turn into the little x's.



In LR, they start out as green, red, or blue pixels with a white halo...then they disappear. I think LR has automatic code that deals with obvious hot pixels. Which is why I wanted Gas am to send his RAW images through ACR or LR, to see what happened. DPP uses a much more primitive demosaicing algorithm than ACR/LR, I don't really think it does much of anything advanced at all. I highly suspect any iPad apps would be the same. 

I would bet that the hot pixel problem largely deals with itself if he would just run the RAWs through LR.


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## eos650 (Jan 21, 2014)

I have the exact same issue (an X), in a couple spots on one of my 5D3's. It's always there. Sometimes, due to color, it's harder to see, but if I look for it, I can always find it. With dark backgrounds it jumps out, so I often hit these spots with the healing tool in Lightroom. I also have some similar white pixels on my 7D, but I don't remember if they form an X. Neither my 60D or 2nd 5D3 have these types of dead/stuck/whatever pixels.

I normally shoot sports. I shoot around 1000th of a second or faster and often shoot ISO 3200 or ISO 6400. It's not a long exposure issue, at least not in my case.


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## Don Haines (Jan 21, 2014)

So I gave it a try on my camera....
ISO320, 30 seconds, in a dark room....

With long exposure noise reduction turned off I got 9 red dots, 2 blue dots, and one white "x".
With long exposure noise reduction turned there were no spots.

It did not matter if I looked at the JPG, the RAW file in lightroom, or the RAW file in DPP, the results were the same... same dots, same color, same location....

and yes, the "x" is a single very white pixel in the centre, with 4 grey pixels diagonally around it to make the "x"

At 1/100 second, there are no spots


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## ahab1372 (Jan 21, 2014)

Long exposure noise reduction is not recommended for ISO 1600 or higher, if I remember correctly from my T3i/600D manual. Not sure if that has changed. Maybe the algorithms are overwhelmed?


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## neuroanatomist (Jan 21, 2014)

Tried a set of 30 s exposures with the lens cap in place (40/2.8 pancake) on my 1D X, ISO 100 and ISO 3200, with and without LENR. Viewing RAW images in DPP, at ISO 100 without LENR, I was surprised to see a whole bunch of off-white spots on the image. Then I figured I should wipe off my display and try again…  

That left me with a single hot pixel in the red channel at ISO 100. At ISO 3200 without LENR, there were quite a few (>30) hot pixels, in all three color channels. After the high quality image rendered in DPP, the green hot pixels were displayed as the little 'x' whereas the red and blue hot pixels retained their original color (but the demosaicing interpolation effect was visible). LENR removed all the hot pixels from the ISO 100 and ISO 3200 images. (Side note: I tried the Auto setting for LENR, and at both ISO 100 and 3200 with the 30 s exposure, the camera decided there was no need to apply LENR, and the images had the same hot pixels as with LENR set to off.)

When opening any of the non-LENR images in DxO Optics Pro, at both ISO 100 and ISO 3200 all of the hot pixels were eliminated. Opening the ISO 100 image with ACR (in CS6, I don't have LR) didn't show the hot red pixel, and in the ISO 3200 image with ACR, most of the hot pixels were removed but ACR left a couple of the red ones in the image.

EDIT: Aperture seems to leave blue hot pixels in the RAW image, but removes the red and green ('x') hot pixels.


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## Quasimodo (Jan 21, 2014)

So if I am understanding this correctly: hot, dead... pixels does not matter so much in practical life, as long as there are no negative effects of LR or CS remove them. I have never seen any such thing on my pictures, which makes me believe that I probably have some, but that the software has taken care of it for me. 

The next thing must be for me to learn how to make an action in LR and PS6 to remove dirty spots from the sensor without leaving any trace  It is a tedious job to attack one and one of them....


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## neuroanatomist (Jan 21, 2014)

Quasimodo said:


> The next thing must be for me to learn how to make an action in LR and PS6 to remove dirty spots from the sensor without leaving any trace  It is a tedious job to attack one and one of them....



You could try an action a little earlier in your workflow… 

http://www.lensrentals.com/blog/2010/04/how-to-clean-a-camera-sensor


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## ahab1372 (Jan 21, 2014)

so the x is a DPP-only phenomenon (or feature)?


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## Mt Spokane Photography (Jan 21, 2014)

Here is a 45 sec RAW exposure from my 5D MK III taken at ISO 100 and developed in Lightroom with no exposure correction, no NR. I did see one little X, but then I wiped it off my monitor.

Since I also saved it as a jpeg image to the second card, its below the raw image:

Then, I increased the exposure in Lightroom by 5 stops. Sure enough, there are some white dots in the jpeg version and some tiny red hot pixels in the raw version. They are hard to see though.

Some photo editors / viewers will boost the exposure automatically, and sure enough there will be white dots. That's completely normal. Also notice how using jpeg locks the blacks.

This is why we can only help someone when we know not only the exposure settings, but if it was RAW or jpeg, and what software was used to view it. A screen grab is of no help and is the type of thing that can be used to mislead inexperienced photographers, but those on this site recognize the issue. I could have told you that the jpeg image 5 stops over exposed was what I'm seeing, and would have received all sorts of advice on how to fix it.

RAW








JPEG









Raw Boosted 5 stops










JPEG Boosted 5 stops


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## Don Haines (Jan 21, 2014)

ahab1372 said:


> so the x is a DPP-only phenomenon (or feature)?



No. I could see it a jpg, in the RAW file viewed in lightroom, and in the RAW file viewed in DPP.


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## Quasimodo (Jan 21, 2014)

neuroanatomist said:


> Quasimodo said:
> 
> 
> > The next thing must be for me to learn how to make an action in LR and PS6 to remove dirty spots from the sensor without leaving any trace  It is a tedious job to attack one and one of them....
> ...



lol! You don*t think that I have not tried that route...  I have, both blowing, dry swab and wet swab on my 1Ds III and 5D II, but I am pretty sure I made it worse than it was. I am scared to apply to much pressure that might destroy the sensor.


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## Mt Spokane Photography (Jan 21, 2014)

Quasimodo said:


> neuroanatomist said:
> 
> 
> > Quasimodo said:
> ...


 
It can be tough to remove some dirt from sensors. I've had to use five or more swabs on a particularly dirty one. Its easy to make it worse if you stop with just one or two swabs and the sensor is still dirty. Keep using clean swabs until the job is finished.
Also be aware that some swabs do introduce fibers and other nasty stuff. they are not all equal. I've had pre-moistened swabs do this while dry swabs of the same brand that I moistened with eclipse were fine.


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## Quasimodo (Jan 21, 2014)

Mt Spokane Photography said:


> Quasimodo said:
> 
> 
> > neuroanatomist said:
> ...



I might have given up to easily... Which brand do you use?


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## Orangutan (Jan 22, 2014)

Quasimodo said:


> I am scared to apply to much pressure that might destroy the sensor.



If I remember correctly, the actual silicon sensor is underneath at least one layer of glass. Don't scour the surface, but the glass should be tough enough that you can apply a bit of pressure.



Mt Spokane Photography said:


> It can be tough to remove some dirt from sensors. I've had to use five or more swabs on a particularly dirty one. Its easy to make it worse if you stop with just one or two swabs and the sensor is still dirty. Keep using clean swabs until the job is finished.



I agree. Sometimes the first couple of swabs just loosen the grime; then it takes another one or two to mop it up.


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## Northstar (Jan 22, 2014)

Have to say that there is some good info in this post...thanks for starting it gas am. I learned something.

Thanks to others who took the time to explore this issue....mt spokane and neuro.


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## jhaces (Jan 22, 2014)

I had similar problems a long while ago (white Xs appearing in random places in my photos) but they would appear *either* in DPP or in LR. They went away from my RAWs after I updated both ACR and DPP. Didn't do any hot-pixel/sensor dust mapping nor cleaning. Is your software up to date?


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## Mt Spokane Photography (Jan 22, 2014)

Quasimodo said:


> I might have given up to easily... Which brand do you use?


 
I use Sensor Swabs (Brand) and moisten them with eclipse fluid. I've had a lot of junk get on my sensors from the pec pads I bought, and from the pre-moistened Sensor Swabs.
Good sensor swabs are not cheap, and when it takes 5 of them plus the expensive eclipse fluid, I cringe. $32 for a dozen ff sized dry ones plus you need the eclipse fluid.

Most of the time, a rocket blower does the job, but I've had some gunk that was difficult to remove on my 5D MK II and my 1D MK III.

Amazon has them.


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## Rienzphotoz (Jan 22, 2014)

Northstar said:


> Have to say that there is some good info in this post...thanks for starting it gas am. I learned something.
> 
> Thanks to others who took the time to explore this issue....mt spokane and neuro.


+1


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## Rienzphotoz (Jan 22, 2014)

Mt Spokane Photography said:


> I use Sensor Swabs (Brand) and moisten them with eclipse fluid. I've had a lot of junk get on my sensors from the pec pads I bought, and from the pre-moistened Sensor Swabs.
> Good sensor swabs are not cheap, and when it takes 5 of them plus the expensive eclipse fluid, I cringe. $32 for a dozen ff sized dry ones plus you need the eclipse fluid.
> 
> Most of the time, a rocket blower does the job, but I've had some gunk that was difficult to remove on my 5D MK II and my 1D MK III.
> ...


It is comforting to note that it does take that many swabs ... I always get scared when I had to use more than 2 swabs, thinking that I might damage the sensor, coz the bloody dust doesn't always go away with a couple of swabs ... so its good to know that I can take 5 swabs or more to get the dust off sometimes. As I shoot in very dusty environments most of the time, I have to clean my sensor frequently, so the info on this thread is very useful.
Thanks to all the useful contributions to this thread. Maybe the mods/admin should put all this good info in a separate thread with a more appropriate title.


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## Quasimodo (Jan 22, 2014)

Mt Spokane Photography said:


> Quasimodo said:
> 
> 
> > I might have given up to easily... Which brand do you use?
> ...



I am wondering if those are the ones I have. I have to check when I get home from the office


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