5D mark iii - dark red dots

[connie_dg]

<p>I've read and seen lots of threads about red dots on photos. I've tried the clean manually trick, turning on the long exposure, and took to Vistek to have sensor cleaned. Nothing worked.<br>

The more I've looked at everyone's photos I've noticed are that my red dots are not bright red. Mine are darker red in colour. I have about 10 of them that show up every single time I take a photo in the exact same spot. Does the colour mean something else? Bad/damaged sensor?<br>

Does anyone know the cost of replacing a sensor through Canon? </p><div></div>

[JosvanEekelen]

<p>Try taking a few pictures with different apertures (f/2.8 to f/22) and see whether the dots change size and/or sharpness. If they do that points to dirt on the sensor but in general these spots are grey/black.<br>

If they are pixel size I don't think there is reason to change the sensor. You're speaking about 10 spot out of 20 million pixels. Search for ways to map them out, if I'm not mistaken the camera has ways to do that, others may point you to directions on how to do so. <br>

If they are bigger than 1 pixel I think you should contact Canon. Is the body out of warranty? </p>

[sarah_fox]

<p>It really doesn't look like sensor dirt, especially since that photo wasn't taken at a very small aperture.</p>

<p>The rule of thirds makes me wonder whether you've taken sunset shots with prolonged use of liveview or video. I've never heard specifically of focused sunlight mucking up a sensor, but it's one of those things about which I'd be leery.</p>

[Marcus Ian]

From your image, its pretty clear these are not single pixel problems, but what is involved depends

on your post processing. This also affects the output color if a group of pixels is hot. The border

intrpolation may have incresed the apparent size of the problem pixels, but it appears to chrome as

if the center of several of the spots is actually white, bordered by magenta. I cant analyze the Rgb

values on my tablet, but you can assess the size and what is actually happening by looking at the

image file as a deliniated text file.

 

All that analysis aside, it appears that the problem results from your sensor. I would do a hard reset,

and upgrade (reinstall) the firmware (not because I expect it to fix the problem, but because its easy,

free, and may possibly help) first. Barring that, youll likely need either a new sensor, or a remapping

of your existing sensor (depending on the extent of the impact). Either way, itll require a trip to

Canon. If so (and they decide a new sensor is in order) this is going to cost a fair amount - though I have no idea how much, since the camera

is obviously no longer under warranty. If they can simply remap the sensor, it shiuld be vastly more

inexpensive, though perhaps you could tell us when the problem showed up, and how it is

progressing?

[paddler4]

<p>Very weird.</p>

<p>These are larger than individual pixels, and they are irregular in both size and shape. They are clearly not sensor dust, which would be dark spots. My first thought was a spattering of tiny amounts of a red liquid on the AA filter in front of the sensor, but you shot this at f/4.5, and I wouldn't expect anything on the sensor to have clearly defined edges--if they showed up at all--at such a wide aperture.</p>

<p>I would shoot a raw image and look at it with no editing at all. If you don't usually shoot raw, you could look at the image in DPP. I would enlarge the image to 100%. I am wondering whether they would show up as constant in size and shape then. </p>

[JosvanEekelen]

<p>The 5D mk III was introduced 2 years ago. When you're in the European Union the camera has a 2 yr warranty so in that case hurry to Canon.</p>

[pge]

<p>I have seen lots of hot pixels and your spots do not look like anything I have seen before. Different shapes, not red, very strange. Any foreign object on the AA filter would not show up as coloured.<br>

Have you tried a different lens? I know this is crazy but it almost looks like wine splatters on the rear element.</p>