I see dead pixels...? [Archive] - Digital Camera Resource Page Forums

Wesan

08-23-2006, 02:44 PM

What do you folks think? Is this dead pixels on the sensor of my Canon S3 IS? I have marked what I suspect are two dead pixels in the photo you can see here:

http://hem.bredband.net/wesake/Pics/Dead_pixels.jpg

The photo is in its original size from the camera. Remember that your web browser might resize (make it smaller) the picture when you look at it there. The dead pixels seem to have shown up during the last month or so.

Is dead pixels a common problem on Canon cameras, or do I just have bad luck?

ben7337

08-23-2006, 02:57 PM

after they are resized I cannot see them. the lowest one might be dust. it looks larger and more undefined on the edges. either way 2 dead pixels out of what 6.3million? is no big deal. that is .00003% of your screen having pixels.

BowerR64

08-23-2006, 03:50 PM

How did you even find it? what gave you the idea to even check it?

Wesan

08-23-2006, 04:17 PM

How did you even find it? what gave you the idea to even check it?

I just happened to notice them on some photos. They are quite obvious when you look at a photo "full size" on the monitor (I have a 19" at 1280 x 1024 resolution), at least in dark areas since they are white. And they appear in the same places on different photos.

But are they really dead pixels, or could they be dust, as ben7337 suspects the lower one might be? Now that you mention it (ben7337), they are different sizes - wouldn't dead pixels be the same size? In that case, where could the dust be? I have cleaned the lens and the UV filter I use and they are still visible.

Since I plan to sell digital photos online, I don't want things like that to show on them.

ben7337

08-23-2006, 04:21 PM

did you clean the inside of the lens? it could also be on the sensor. the 1 little pixel that is dead is no big deal I do not think. many people have dead pixels in lots of technology including tv's and portable media devices. 1 little pixels in those things is no big deal and a photograph should be no different. unless you are going to do a ton of cropping or something.

Wesan

08-23-2006, 04:48 PM

did you clean the inside of the lens?...

No, I have not cleaned the inside of the lens. I am not a very "technically handy" kind of person :o and I also don't want to make the warranty become void. So I don't want to take the camera apart myself. I saw BowerR64's description on how to take an S2 apart - yikes! That's a lot of parts not to break or lose! :eek:

ktixx

08-23-2006, 05:09 PM

Don't take the camera apart unless you really know what you are doing. If you are that bothered by the pixels I suggest sending it back to the manufacturer. If it is still under warranty they will probably fix/replace it for free.
Ken

Andrizzle

08-23-2006, 05:26 PM

I really doubt that either of the dots are dust.

How did you get the photo? You blocked the lens so that no light could get in, in order to get a baseline image, right? Well if there is no light, then how would dust light up and show up in the photo?

So don't worry about opening it and cleaning the inside, or any other part of the lens. Unless you have some special, florescent, radioactive dust that is...

Wesan

08-24-2006, 04:36 PM

I took a closer look at the lens last night (no - I didn't open the camera, only looked into the lens from the outside... :o ). It looks like at least one of the "dead pixels" could be some kind of dust or dirt on the inside of the lens, deep inside it. I could only see it at a specific zoom interval, if you see what I mean?

I have never opened the camera and it's only about 3 months old. So how could this dirt or dust come inside? :confused:

Lupin III.

09-25-2006, 12:51 PM

I have bought a Canon S2IS 9 month ago. I am sure, there weren't dead/hot pixels in the beginning. But look at the appended images I get now. Looks more like a starry sky than black. Actually that's the way I found them the first time: while taking a series of night-sky images, where I suddenly had new "fixed stars". It got worse since then. I looked at many previous images and can see the dead-pixel-count go up.

The photos are taken at 100 and 200 ISO with an exposure time of 15s. I dont't take ISO 200 images that often, as there is often too much noise, but it shows the candidates for the next round of dead pixels. I held the camera lens down on the cap. I then used edge-detect in GIMP to make the points visible in the scaled down version (wouldn't let me upload larger images). The dots aren't that large in the original image, but all visible, even at shorter exposures.

Until I read the threads in this forum, I didn't even think I had a chance of replacement, and they would tell me 30 dead of 5million pixels isn't an error. But as most of you already got replacements for 2 or 3 pixels, my camera will be off to service this week. I hope Canon in Europe is as co-operating.

JTL

09-25-2006, 12:59 PM

That's way too many bad pixels to be considered acceptable...

Fight to have it fixed or replaced...

claytonb

09-25-2006, 02:10 PM

Gosh, that looks bad. I had one dead pixel on the CCD and Canon in Montreal ended up replacing the whole optical unit and now the system works great.

Best of luck..

Alnath

09-25-2006, 04:11 PM

at one second or less the i dont think the S3 will be using dark field subtraction so hot pixels will show up anyway, you should see my 20D, its plastered with them from new on long exposures.

BowerR64

09-25-2006, 05:17 PM

You can use super macro and holding the lens really close to white paper you can take a picture of the front lens. You have to be in super macro, and in manual mode. Then you can focus the camera on teh front glass and see all the dust. You might be suprised how dirty it actualy is.

http://i5.photobucket.com/albums/y191/BowerR64/Junk/dirtylens.jpg

truflip

09-25-2006, 05:24 PM

ermrmm.. n u guys think u got the worst pixel problems... *sigh*

TEMPA

09-25-2006, 05:41 PM

ermrmm.. n u guys think u got the worst pixel problems... *sigh*

Hey truflip,

I assume that pic is taken with the camera lense blocked?

What happens as a matter of interest if you take a pic with your S3 in a darkened room but without blocking the lens?

I would be interested to see the result.

I have seen your other pics taken with the S3 and I would say there are no issues at all.

I just wonder if something is going on in the circuitry of the camera when the lense is completely blocked or when there is absolutely no light? Does shutter speed or aperture make a difference to the result when the lens is blocked?

Surely if these are faulty pixels we are seeing they would be visible in the long expossure night shots people are taking and also in the moon shots most of us have tried. Wouldn't they?

TEMPA

truflip

09-25-2006, 06:17 PM

TEMPA,

its actually a shot of the sky while my gf and I were star gazing one night in august.. :) believe aug 12.. not sure if u know of the meteor showers then, but that was the peak of it.. we saw at least 5-6 good ones in 30 minutes... not bad.. woulda been better early in the morning but we couldnt stay awake that long :) the camera used was the Fuji F30 at ISO 1600 and 15" shutter speed..

look.. in one of the pics i actually found a star clutter... its very small n hard to see on the full res pic so i increased the size to 2x and sharpened a bit.. cool eh! anyway i'll get some test pics from the S3 in total darkness =)

TEMPA

09-25-2006, 06:32 PM

TEMPA,

its actually a shot of the sky while my gf and I were star gazing one night in august.. :) believe aug 12.. not sure if u know of the meteor showers then, but that was the peak of it..

Sorry mate,

I assumed that was a comparison shot from your S3 to show potential dead pixels. My bad....

Since they are actually stars and or meteors in the shot and not dead pixels they are cool then!!!

TEMPA

truflip

09-25-2006, 06:43 PM

naahh dont say sorry.. its my fault.. i felt like being sarcastic n posted something of the sky.. hehe my bad.. but i owe u guys one.. im gonna go take some pics in the dark.. i jus took some sample shots of pics with n without flash diffusers for someone on the other thread.. brb soon!

truflip

09-25-2006, 06:51 PM

ok heres my test shot.. the first one is at 1/400 shutter.. i tested some out 1" shutter but they look the same.. the second one is the the lens covered so no light gets in.. looks the same.. and looks like no dead pixel.. do u have a dead pixel on ur sensor too TEMPA?

http://img141.imageshack.us/img141/9761/img7864su8.jpg

truflip

09-25-2006, 06:52 PM

heres the 2nd one... i realized this starts another page.. so if u wanna see the first one.. well, chek the previous page :p

http://img201.imageshack.us/img201/5924/img7865ur8.jpg

TEMPA

09-25-2006, 07:08 PM

and looks like no dead pixel.. do u have a dead pixel on ur sensor too TEMPA?

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I dunno if I have or not.

Haven't tested it out. I am at work at the moment but will be giving it a go when I get home later today, that's for sure.

Just in case. I bloody hope not though...

TEMPA

JTL

09-25-2006, 07:24 PM

My S3 is clean...but my S2 developed around 10 of them after about 9 months...

TEMPA

09-26-2006, 06:33 AM

Luckily and thankfully no dead pixels to be seen on my S3 pics. Phewww!!!!!

TEMPA

truflip

09-26-2006, 07:27 AM

coool! lets give it a few months.. lol jk lets not jinx it.. im leaving this thread :p dont wanna hear bout pixels on sensors no more :(

Wesan

09-27-2006, 02:14 PM

I (finally) contacted the online store where I bought the camera and told them I think there are dead pixels on the sensor. They have sent me instructions about how and where to send the camera to a service center and included a dispatch note (right word?), so I won't have to pay the postage. It may take two to four weeks to get the camera fixed. A long time to be without a camera. :( But hopefully, I will get it back in perfect shape! :D

downtrodden

09-27-2006, 02:41 PM

I see dead pixels.. i'm sorry.. but sounds like a line from a cheesy drama/horror movie targeted at digital camera audience..

Sorry. had to.:D

Wesan

09-27-2006, 06:13 PM

I see dead pixels.. i'm sorry.. but sounds like a line from a cheesy drama/horror movie targeted at digital camera audience..

Sorry. had to.:D

Hehehe... :D Actually, I was "inspired" by the movie "The Sixth Sense" with Bruce Willis, where the boy says "I see dead people", when I decided the name of this thread. So I did have a movie in mind! :D

Hawkstone

09-28-2006, 03:30 AM

Wesan

09-28-2006, 06:06 PM

Hi Wesan,

I have an A620 and after a few months my camera had developed some dead pixels, I posted some info some time ago about this. You may still be able to find it.

There is a program you can download for free from the web that tests images for dead pixels. I used it on your images and there were no dead pixels, but there were a few thousand hot pixels.

The program is called DeadPixelTest. If you can't find it PM me and I'll send it to you.

Regards,
Hawkstone.

Thanks Hawkstone! I found the program. The photo example I posted, was not the best one to search for dead pixels on, I learned. :o But it showed the two pixels I was wondering about.

I took another photo that was more appropriate for the test and ran the program. It found 9 hot pixels and no dead pixels.

Anyway, I'm going to mail the camera to a service center and see if they can do something about it. I still like to get rid of those "dots", even if they're not dead pixels. Though I'll miss my camera while it's away. :(