Red dot in photos

<p>I have a new 500D with the kit lens. I took it out for a few test shots at night and almost all the photos with a long exposure (around 10 secs), have a red dot on them at the same place. I could not see this on some of the brighter images.<br>

Is this a dead pixel on the camera? Can I do anything about it at all?</p>

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<p>[[Can I do anything about it at all]]</p>

<p>Enable noise reduction with the custom function and you are not likely to see the hot pixel again.</p>

<p>A dead pixel is always black regardless of exposure time. A hot pixel just shows up with longer exposures.</p>

 

<p>When was the last time you cleaned the sensor?</p>

<p>I have never cleaned the sensor. It automatically cleans the sensor each time I turn it off.</p>

<p>These are dead or hot pixels, it is not a cleaning issue. You can either enable the noise reduction function as Rob suggests or you can very easily remove it in any post processing. I tend to favour the latter as I always forget to enable the noise reduction program and when I do it takes twice the time to take each photo as the camera takes a second exposure with the same time as the first (with the mirror down).</p>

<p>So it's more or less a defect in the camera? It bothers me a lot that I'll have to take either of the steps as mentioned above to correct the problems each time. Should I try and get a replacement? If they can't replace it, can this be repaired?</p>

<p>Almost every DSLR you buy has a dead or hot pixel. It's a fact of sensor life:-) It's not a big deal.</p>

<p>Its not a defect on a long exposure, thats the way sensors work. If it shows up on more normal exposure times, then it would be a defect.</p>

 

<p>This is common and doesn't warrant a replacement.<br>

I use Lightroom, which corretcs these hot pixels automatically, so I never even get to see them. I would think, DPP and other applications do the same.</p>

<p>It is not a dirty sensor. Yes, hot pixels are a fact of life but, no, they don't have to appear in photos such as this. And you do not want to rely on your post-processing software to deal with the issue in the case of long exposures like this one. There is a setting on your camera that will eliminate the "problem" on long exposures.</p>

<p>You need to turn on the long-exposure noise reduction setting on your camera. (This is different from normal "noise reduction" settings. Check your manual.)</p>

<p>This will eliminate the red (and green and blue) dots. This setting causes the camera to take a second "dark frame" exposure following each long exposure. The dark frame exposure does not capture the scene - it only captures the "hot pixel" and noise data. It then subtracts this data from the actual image to virtually remove these normal hot pixels and increased noise.</p>

<p>(A downside that you'll learn to live with is that it will take you twice as long to make an exposure. If you make a 30 second exposure, the camera will take another 30 seconds right after that to make the dark frame exposure.)</p>

<p>It is a simple issue. I do a lot of night photography, and I would never do a long exposure w/o this feature enabled.</p>

<p>Dan</p>

<p>I've seen this before in my camera and cleaning the sensor got rid of it. If you have a blower (without the brush end to it) I'd start there, it'd take 10 seconds. Your cameras cleaning is no where near thorough, it just vibrates the sensor a bit. I see a spot in the tiles just bellow the two people with tripods. Your sensor could use a cleaning at any rate.</p>

<p>Also, that original spot looks bigger than a pixel, so if it's a hot pixel you have a hot spot and not just one pixel. That one white spot off to the far right is a pixel, this is 4 or 5. If this bad pixel spot happens all the time I'd wonder how Canon would stay in business. Nikon would undoubtedly take over with the pros on quality standards alone.</p>

<p>But we could go round and round about this. Contact Canon and don't let me or anyone else lead you in circles.</p>

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<p>If this bad pixel spot happens all the time I'd wonder how Canon would stay in business. Nikon would undoubtedly take over with the pros on quality standards alone.</p>

 

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<p><em>Eh? </em></p>

<p>You <em>can't possibly</em> honestly believe that hot pixels are the sole domain of Canon and that Nikon bodies don't get them, can you?</p>

<p>Jeez. Wanna buy a bridge?</p>

<p>Folks, dust spots on the sensor do not produce RED dots. Long exposures without long-exposure noise reduction turned on DO produce red (and green and blue) pixel-sized dots.</p>

<p>Trust me on this one.</p>

<p>Dan</p>

<p>Update. The place I bought it from said that I need to send the camera to Canon for repairs. So, I decided to try out Dan Ferrel's suggestion first and performed a sensor cleaning on the camera. Guess what? The red spot disappeared. It's turned into a somewhat smaller, white/grey spot. Can anybody explain this please?<a href="../photodb/user?user_id=3898900"><br /> </a></p><div></div>

<p>The second sample you posted shows a bad pixel. I'm assuming that this is not a long exposure...</p>

<p>The spot can "disappear" if your image software knows how to map out bad pixels. Several current programs will do this after they have "seen" a few images from your camera.</p>

<p>Dan</p>

<p>It's perplexing because I used the exact settings as before. 100 ISO and a 10 second exposure. It's barely noticeable but, still there and it's white now.<br /> </p>