# More dead pixel problems for canon



## Gas am (Jan 12, 2014)

Previous threads on dead pixels are too old for replies it would seem. So here's a new one 

I have just bought an EOS 700d. Amazon delivered and all seemed well with the camera until I tried a long exposure. At 15 secs I get stuck/ dead pixel in a corner.
Amazon replaced the camera immediately. The replacement was worse. There is a cluster of dead pixels and several red and blue pixels. Amazon have again been very understanding and have dispatched a third body to me.
I called canon UK and they told me that they had no known issues with the 700d and that they were not prepared to listen to Internet forum talk of sensor issues. They would of corse repair the camera if it was faulty, under its warrantee. But the canon rep told me that the sensors have 99.99% effective pixels. Does this mean that canon would accept 1,800 defective pixels. If the rep meant 99.9999% then this would still mean 18 dead pixels. 
The 3rd replacement will arrive tomorrow. If this is faulty, what should I do?
As I have yet to return any of the cameras, should I keep the best one and send it to canon for inspection/ repair? Should I accept bad pixels from new? My photos do include lots of long exposures, so accepting defects from new seems to be wrong. Am I being unrealistic?
Any help would be muchly appreciated )


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## privatebydesign (Jan 12, 2014)

You need to post an image for relevant feedback.

By fix, all any company will ever do with dead pixels is map them out. You can do that yourself with many Canon cameras How To Fix A Hot or Dead Pixel (Canon 7D & 5D & others)


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## neuroanatomist (Jan 12, 2014)

I'd just remap the pixels rather than waste time sending camera after camera back.


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## Gas am (Jan 12, 2014)

The remap trick with the body cap and a 30 second lens clean?
If so it has not worked for me


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## neuroanatomist (Jan 12, 2014)

Gas am said:


> The remap trick with the body cap and a 30 second lens clean?
> If so it has not worked for me



In that case, sending them back isn't a waste of time (sorry!) but your best option, since Canon will likely just say it's in spec, as long as its not a large cluster or a whole line.


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## 9VIII (Jan 12, 2014)

Unfortunately if you follow the trend of returning cameras with faulty pixels after a 15 second exposure I'm pretty sure you will buy and return every digital camera in the world, and find none that aren't "faulty".
Last year I sent my new T3 in for re-mapping, they did a good job with the spots I pointed out, but after doing some more macro shots this week I see that I'm back to square one with a couple of spots near the middle of the frame.
The answer, is I try if at all possible to keep my exposure to 1 second or less, where I know the image will be clean. Sometimes I'll push it, but do so keeping in mind the possibility of bringing out the dots. If I do a 15 second exposure with my 5D2 it looks like a Christmas tree. The "manual cleaning trick" seems to eliminate the worst ones, but there are dozens of weaker faulty pixels that seem to get ignored by the remapping program.

When your 3rd camera arrives tomorrow, I would pick the best of the two. Chances are most other people won't be doing a lot of long exposures and will never see the problem. There have been cases where people have abnormally bad stuck pixels, but this sounds like normal camera behaviour.


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## jrista (Jan 12, 2014)

Gas am said:


> Previous threads on dead pixels are too old for replies it would seem. So here's a new one
> 
> I have just bought an EOS 700d. Amazon delivered and all seemed well with the camera until I tried a long exposure. At 15 secs I get stuck/ dead pixel in a corner.
> Amazon replaced the camera immediately. The replacement was worse. There is a cluster of dead pixels and several red and blue pixels. Amazon have again been very understanding and have dispatched a third body to me.
> ...



_You really need to post some sample images._ I think you are freaking out over nothing. Stuck and dead pixels are a part of digital photography life. EVERYONE gets them, and in general, especially for longer exposures like 15 seconds or so, you should have dozens of stuck and dead pixels (properly called hot and cold pixels) all over the frame. This is a simple facet of sensor design and manufacture, due to nanoscopic impurities in the silicon material the sensor is etched out of. Unless you have a very LARGE block of hot/cold pixels (and I mean, a lot more than 18, like 50x50 or more), I really think your pixel peeping just a little bit too much. And if you truly only have 18 hot and cold pixels, then you are actually making out like a bandit. With 15-30 second night sky photos, I have at least a hundred of these buggers scattered across my frame. They are pretty easy to clean up with a spot healing brush or a remove dust and speckle filter.


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## Gas am (Jan 12, 2014)

Thanks for your thoughts people 
So, Say I accept the dead pixel camera. What do you guys use to delete these suckers from your images? I was using photoshop elements and its repair tool. Should I be shooting in raw and the importing through lightroom. And having adobe get rid of these aberrations?
I do a lot of church stone carving shots. Especially greenmen. These are often found high up in dark flash no go zones. Long exposures is my only weapon in most cases. Any ideas? 
Thanks in advance


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## jrista (Jan 12, 2014)

Gas am said:


> Thanks for your thoughts people
> So, Say I accept the dead pixel camera. What do you guys use to delete these suckers from your images? I was using photoshop elements and its repair tool. Should I be shooting in raw and the importing through lightroom. And having adobe get rid of these aberrations?
> I do a lot of church stone carving shots. Especially greenmen. These are often found high up in dark flash no go zones. Long exposures is my only weapon in most cases. Any ideas?
> Thanks in advance



Could you post an example? I mean, if it really is some huge cluster of pixels, you should do something about it...there shouldn't be large contiguous regions of hot or cold pixels. Hot pixels (which are most common) tend to be scattered throughout the frame, and don't generally bunch up more than a few pixels at a time. Dead pixels, which are also scattered, are usually delt with by the demosaicing algorithm (such as in Lightroom or ACR), and you shouldn't notice them most of the time, and when you do, it will normally be against very bright backgrounds.

If it is just random hot and cold pixels that every sensor has, I offered before that you could use a spot healing brush or dust and scratch removal filter, as the most effective tools. Spot healing brush in LR, or the content-aware spot healing brush in photoshop, are usually the most effective. Also, keep in mind, hot pixels tend to show up more at higher ISO settings as well as in lifted deep shadows of lower ISO shots. 

If you are not going to be printing these photos, you should simply try downsampling. For the most part, you don't really have to deal with hot pixels yourself unless you intend to enlarge and print huge. For the vast majority of photographs that get uploaded to the web somewhere, your downsampling considerably, and that will eliminate 99% of hot pixels for you 99% of the time.


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## photonius (Jan 12, 2014)

Gas am said:


> Previous threads on dead pixels are too old for replies it would seem. So here's a new one
> 
> I have just bought an EOS 700d. Amazon delivered and all seemed well with the camera until I tried a long exposure. At 15 secs I get stuck/ dead pixel in a corner.
> Amazon replaced the camera immediately. The replacement was worse. There is a cluster of dead pixels and several red and blue pixels. Amazon have again been very understanding and have dispatched a third body to me.
> ...



since nobody mentioned it, did you use long exposure noise reduction? that's what it's for.


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## alexturton (Jan 13, 2014)

if you shoot raw I'm fairly sure lightroom autmatically maps out hot pixels in long exposures. If the hot pixels were there in normal shots I'd be more concerned, but in long exposures (as mentioned above) its not uncommon.


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## Gas am (Jan 13, 2014)

My third body arrived today. Unfortunately the courier had dropped it in a puddle. The box was falling apart ;( I won't be trying to charge the battery.
Amazon are sending out another body. I must have been very bad in a past life


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## yeahyoung (Jan 13, 2014)

jrista said:


> Gas am said:
> 
> 
> > Previous threads on dead pixels are too old for replies it would seem. So here's a new one
> ...



^ This ^ Long exposure photos from digital sensors are prone to hot/cold pixels by design.


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## DigiAngel (Jan 14, 2014)

hotpixels are totaly normal and you have to have very good luck to find a camera without some. i cant believe amazon really replaced the cameras? 

any raw software should have options to map them out. so i dont understand the problem here. never had a camera without them. and even if you have luck, they can appear anytime later.


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## 9VIII (Jan 14, 2014)

I was processing some pictures today, on DPP if you turn up Luminance Noise Reduction to 10 and Chrominance Noise Reduction to 20 it takes the colour out most of my worst spots. You can go halfway with the NR (LNR 5 and CNR 10) to keep a little more IQ if the spots aren't as bad.


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## Gas am (Jan 15, 2014)

The forth body arrived today and has been returned. It had several red and blue pixels and a small cluster of stuck pixels. Again these were not obvious untill I went looking for them in long exposures. So after all the swapping it seems the origional body had the least issues. 
Thanks for all your advice. I will have to deal with the issue by either shooting in raw or by using the long exposure noise reduction. My only other option would be a lighting rig and a scaffold tower.

Cheers


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