Hot pixel in my 20D, should I return it?

[Toogy]

I just got my 20D today and did some long exposures (8-13 seconds) and I have noticed a RED hot pixel in every one of my shots.

I know it can easily be cloned out, but should I just return it for another one?
What would you do?

Thanks

[FlipsidE]

Hot pixels have been known to turn up at shutter speeds longer than 1/10. If it were me, I wouldn't worry about it. As long as you aren't seeing it a shutter speeds shorter than 1/10, I think you're good to go.

FlipsidE

[Toogy]

Upon further review I notice it on some ISO 800 shots I took at 1/50 second as well. Not as bad, but it's there.

[LouDawg]

All of these digital cameras will have some hot pixels. There's nothing you can do about it. Chances are that if you returned it for another you might even get one with a worse problem. If it's a really big problem use the long-exposure noise reduction feature.

[FlipsidE]

Chances are that if you returned it for another you might even get one with a worse problem.

SHEESH...I know that TOO well. Sometimes, I think it might be best not to take the chance.

Anyway, back to the main topic. Higher ISO will also make hot pixels show a lot more. I'm sorry I forgot to include that in my original post in this message. Either way, your camera sounds fine.

Edit: On a couple of my old DRebels, I had one or two hot/dead that showed up even at like 1/200 at ISO 100. I call that a problem. But, I think you are just fine.

FlipsidE

[pcasciola]

That's unusual for a 20D. I did some long exposure tests with mine and they were extremely clean.

Here are some tests I did a while back. Even with multi-minute exposures I had to look pretty hard to find the noise except in the extreme cases where I tried 2-5 minutes at ISO 1600.

http://photography-on-the.net/forum/showthread.php?t=46024&highlight=

If it's that obvious in every shot you are taking, I might be inclined to return it. Can you post an example? Maybe a 100% crop of the affected area?

[Toogy]

Ok here is what I am talking about
Full picture
http://www.digitaliso.ca/20D.jpg

In the frame of the fireplace in the background, is the hot pixel

100% crop
http://www.digitaliso.ca/Hot_pixel.jpg

[tim]

I'd probably talk to the place I bought it about exchanging it. When you buy a camera that expensive you expect it to work perfectly.

[Persian-Rice]

Tim, when I buy any camera I woud expect it to work flawlessly. Hey, there is no harm in returning it............other then you ger a camera without the hot pixel.

[pcasciola]

Persian-Rice is right. You paid $1500 for a camera, it should work perfectly. You shouldn't have to be bothered with cloning that out every time you take a 5+ second exposure. I'd definitely return it if I were you.

[wtfmate]

My very first 20d that I picked up had a dead pixel, I went and returned it and got another one, then that one had a defect on the lens, so I had to go back and get a new lens, im on my second 20d, and my 3rd lens

This one is perfectly fine though :D

[drisley]

... :arrow:

[drisley]

Toogy, that is completey normal.
Only 1 hot pixel at extended exposures/high Iso's is actually very good, even for the 20D.

[leonid]

All digital cameras have some hot pixels. You should evaluate the severity of the problem.
Try to find out the number of hot pixels and their luminance.
Here are test results for my Digital Rebel done at ISO 100 (Of course at ISO800 it would be much more of them):

- At 1" exposure I've got 1 hot pixel with a luminance 30 or greater.
- At 30" exposure I've got 24 hot pixels with a luminance 30 or greater. 6 pixels had luminance 60 or greater. With a "naked" eye I could see only thee dots on the screen. But each dot contains several pixels.

I used the program http://www.starzen.com/imaging/deadpixeltest.htm.

[Toogy]

Using that program at ISO200 for a 20 second exposure I got 7 hot pixels with a luminance over 60 and 17 over 30. When looking at the image I can only see that one red pixel, perhaps they are 7 there?

Acceptable?

[drisley]

Using that program at ISO200 for a 20 second exposure I got 7 hot pixels with a luminance over 60 and 17 over 30. When looking at the image I can only see that one red pixel, perhaps they are 7 there?

Acceptable?
Yes, that is more than acceptable.
FYI, check out some of the camera review sites on the web.
Check out some of the long exposure and or high ISO sample pictures they post. You will always find one or more hot pixels.
If these cameras that are hand picked by the manufacturer for review have hot pixels, it's more than acceptable for the average consumer camera to have them too.

[Toogy]

I think I will keep it, it worked AWESOME today with my Tamron 28-75 and Canon 70-200 F4.

Here is a shot of my friend that was with me today, shot with the 70-200 F4. And a landscape shot with the Tamron. I am pleased

http://www.digitaliso.ca/IMG_0117.jpg

http://www.digitaliso.ca/IMG_0155.jpg

[tim]

Damn, those are nice photos, and they look razor sharp.

[drisley]

Wow!
Those are awesome shots!

BTW, I would bet that if you exchanged the camera, you would get another one that would show atleast 1 hot pixel at long exposures. ANd that is if you are lucky. If not, you would probably get one that shows more than 1 hot pixel.
Again, as long as the hot pixel only shows up at exposures longer than about 1 second, that is normal.
BTW, the 20D has a custom function to enable "Long Exposure Noise Reduction." This is really mislabelled as it doesn't reduce the noise on long exposures (as the noise is already very low on the 20D). In fact, it actually reduces/eliminates hot pixels by taking another blank shot of equal length and subtracts the hot pixels from the image. It works on shots of 3 seconds and longer (I think).
You should enable this feature, and let us know if the hot pixel is still there :)
I have 1 hot pixel like yours on long exposures at ISO100. When I enable this feature, the hot pixel is gone! It also cuts down the number of hot pixels on really long exposures, or long exposures at high ISOs, down by 50%.

If you have a look at the 30sec exposure samples at Steve's Digicams (http://www.steves-digicams.com/2004_reviews/20d_samples.html), you can spot atleast 2 hot pixels in the regular picture. With noise reduction enabled, both hot pixels are gone

[TonyKInTexas]

I have a hotpixel on my 10D. ISO 100 and 1600 at shutter speeds from 1/200 down to 30 seconds.

It seems to be triggered more by my holding the shutter half down for focus lock more than anything else.

And the kicker to this, Capture 1 hides the hot pixel. All the other converters show it. Some worse than others.

I just got my 20D today and did some long exposures (8-13 seconds) and I have noticed a RED hot pixel in every one of my shots.

I know it can easily be cloned out, but should I just return it for another one?
What would you do?

Thanks

[Persian-Rice]

It seems to be triggered more by my holding the shutter half down for focus lock more than anything else.
[/quote]

FYI Holding down the shutter halfway will not trigger a hotpixel.....

[TonyKInTexas]

All I am saying is what I am seeing. If I don't hold the shutter down, no hot pixel. If I hold it down while I wait for "the" moment, I tend to get the hot pixel. I am fortunate in that it is only 1, I know where it is at and can fix it easily in my photos.

And with C1LE, it masks it completely. I have asked the people at Bibble to look at doing that because I think it is a neat feature, intentional or not.


It seems to be triggered more by my holding the shutter half down for focus lock more than anything else.


FYI Holding down the shutter halfway will not trigger a hotpixel.....[/quote]

[Persian-Rice]

Well ok, but knowing how hot pixels are caused in pretty good detail, I'm 99% sure that is not the reason. However, whatever works for you, works for you I guess.

Just for the hell of it, try seperating the Meter and AF buttons in C.Functions.

[TonyKInTexas]

I'm not saying it makes sense. If it were a stuck pixel it would be present 100% of the time. A hot pixel also has characteristics that define it and this one pixel behaves like a hot pixel.

My theory, though I have not exposed it yet (about to though) is by keeping the system charged (focus lock) is somehow leaking in to the imaging sensor and causing the pixel to get hot.

Otherwise, what I am seeing is truly random behavior (possible). But it is only one and easily fixable. As has been noted, I could send the 10D in for repair and get it back in worse shape. Not sure I like them odds. :)

Thanks,

Well ok, but knowing how hot pixels are caused in pretty good detail, I'm 99% sure that is not the reason. However, whatever works for you, works for you I guess.

Just for the hell of it, try seperating the Meter and AF buttons in C.Functions.

[drisley]

BTW warm temps will also increase the number of visible hot pixels.

[TonyKInTexas]

Inside venues so temps are pretty consistent.

Thanks,

BTW warm temps will also increase the number of visible hot pixels.

[CyberDyneSystems]

Toogy,

Your shots look great!

IF I were getting a red hopt pixel with normal shutter speeds.. I would return it..

You mention at least one image where the pixel showed up at 1/50th of a second... this to me would be unnacceptable.

Just my opinion.

[Toogy]

I did a bunch more test shots, and it shows ups at 1/20th second at ISO 3200, and also at ISO100 at 1.6 second exposure.

Does this still sound acceptable?