Hi

Well I have a new canon EOS 350D, it is 1-2 months old, and only now I have noticed that there are glowing pixels visible at long exposures around 30 sec. I checked my first long exposure shots, and they also got them, at the same pixel positions I did a shot in completely black room, and counted 19 highlighted pixels total. Both red, white and blue.

So is this common ? What can I do to get rid of these nasty problems ?

Here is a shot from that room, I pointed out the pixels, so it would be easier to find them.
<img src="http://show.imagehosting.us/show/1371561/12414/user_12414/T1_12414_1371561.JPG" border="0"/>

Common? Yes, I would think so .. same is true for LCD monitors .. I don't know if you can fix the camera .. but here is a plugin for the images .. Never used it myself


HotPixel .. FREE

HotPixel is an Adobe Photoshopİ compatible filter/plugin designed to remove "hot pixel" noise from digital images.

if you have 19 of them you may be able to get some warrenty work done. Ussually they don't care if there is 2 or 3 but often there is a number that if it is above they fix. I dunno what canon does, but you should get in contact with them and find out.

You could always use the healing brush or the clone tool from photoshop to get rid of them manually, but that would be a pain for batch edits.

Usually when I come across this problem, there is something wrong with the sensor. I would personally take it back to the store or call the support on the website and get them to fix it.

Thank you guys, at least I know that is not so common, I would contact canon. Thank for suggestions on how to remove these pictures from the image, but I don't have photoshop :) so there isn't much I can do about them.

the plug-in will work in any program that uses the adobe standard ... even Irfanview, possibly, since it will use standard .8bf filters

Hi, I got this reply from the canon.

Dear Customer,


Thank you for your recent enquiry regarding your Canon product.

If you only see the particular pixels with very long exposures, they are not likely bad pixels, but digital noise. The noise pattern of a digital camera can often be very regular, as you have seen. This makes it easier to remove. See this page for some more information:

http://web.canon.jp/Imaging/astro/pages_e/12_e.html

And it does make a sense, if there were a bad pixels, they would be visible at any exposures. Still some pixels are more sensitive to longer exposures. Anyway some pixels are visible even on 20 sec exposures, and probably less then that. I have found a way how to remove any of these. There is a noise removing function for long exposures build within camera , it removes all of them without any loss of quality, but takes extra time.

I clicked my Canon S2 IS with the lens cap on...normal exposure in auto mode and checked it out...1 dead pixel, cool, I won't complain. How's yours look say in auto mode..just a quicky snap with the cap on?

I'm posting the following links from DSL-reports in case those of you with this issue can glean any info .. my eyes rolled back into my skull while reading .. since I don't use the camera I have enough to know whether it has a problem

*SIGH* Long exposures - I think I'm going back to film

Red pixels and a dark spot

Yes that does look like true. Here is a program the guys used to count the dead(Hot) pixels. deadpixeltest. The picture should be made with a cap on. As I understand the longer the exposure, the more noise is visible.

Doesn't the Canon have a built-in feature to remap those pixels? I would imagine that any decent camera should have a utility built into it to map out those dead pixels. The Olympus cameras have had it for years. This is a common problem with digital cameras. Every one I've had has developed it eventually, but the camera probably has the remapping utility built in. Check up on that with Canon. If they don't let them know that you're displeased.

Well I mentioned about the build-in noise remove function, it works, but takes extra time :)

Actually the Olympus cameras have a utility that remaps the ccd to not use the dead pixels. Rather it averages the nearby pixels to determine what color/intensity to substitute for the dead pixels. I just assumed that was standard on all cameras. I'm surprised to hear that a top of the line camera like the Canons don't have such a basic feature.

The first Powershot A620 I bought a few weeks back suffered from these problems. It had one dead pixel (always white on all shots) and one hot pixel (always blue on long exposures). Luckily I noticed it so I got the camera replaced and the second one was fine. In the meantime I found an excellent utility called dead pixel test (http://www.starzen.com/imaging/deadpixeltest.htm). Take some lens-cap-on shots, feed them into the test and it'll identify any hot or dead pixels. I'll be using this whenever I buy a new camera from now on.

The research I did seemed to indicate that this problem wasn't nearly as common in camera sensors as it is in LCD/TFT monitors. Have you approached the place you bought the camera to discuss an exchange?

No I didn't, I don't have a clear dead pixels, but hot pixels. Whats the point for exchange if nearly all the cameras have them. And if the camera has a build in noise remove function, that removes them all, then no point at all.