Digital Rebel Hot Pixel

[drisley]

I just got my new Digital Rebel.
I took a couple shots in low light and noticed a "white pixel".
I assume this is a hot pixel.
I also took a picture with the cap on, and then increased the white levels, and the white pixel shows up again.

Is this normal with this cmos? Would you return it?
I ask because I have to send ordered online, and have to send it back across country.

http://www.mts.net/~lftbrain/hotpixel.jpg

[hawg]

return it if you can. I got one on my D60 and thought I can just live with it and correct it in PS. Also, I waited over 3mos for the D60. But, it bugged me so much after a while. Then it got harder to return since I got used to having the camera. :(

[robertwgross]

Make sure that it is a hot pixel on the sensor, which is moderately serious. The other problem is a hot pixel on the rear LCD screen display, which is not nearly so serious.

---Bob Gross---

[drisley]

Thanks, yes, it is a hot pixel on the cmos.
If it was only the LCD, it wouldn't show up in the pictures.

[robertwgross]

Thanks, yes, it is a hot pixel on the cmos.
If it was only the LCD, it wouldn't show up in the pictures.

One guy took a photo of what showed up on the rear display, and it showed a spot. The actual digital image did not, so his was not so serious.

---Bob Gross---

[drisley]

Just my luck!

I went thru three S30's because of hot lcd pixels. Then two G3's because of the same problem.

I order this one online becaue I saved alot of money. I was so happy when I got it and it didn't have any hot lcd pixels. But now a cmos pixel. arghhh!

The store apparently will exchange it, but I just got my camera, and now I will have to be without it for a couple weeks. Plus $$ spent on shipping.

I wonder what the chances are that the next camera would have a hot pixel too?

:(

[drisley]

Hmmm, I read this topic in another forum.

http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=006URA

This dude had a hot pixel too on his 300d. He went to the shop, tried 2 more, and they both had atleast 1 bad pixel. I wonder what the odds are.
Perhaps it would not be worth the time and money?

Is there a way to setup an action in PS to use the healing brush?
I tried, but the healing brush doesnt seem to be supported as an action (ie, to heal a certain pixel with another pixel).

[richardtallent]

My 300D also has a hot pixel (green) in about the same spot rotated 180deg. I notice it on the preview in C1, but have not noticed it on final TIFF exports, so I assume the conversion algorithms catch it and take care of it automatically. A minor annoyance, but 1 sensor out of 6.3m isn't an issue for me (certainly not enough to try to get the camera replaced).

[drisley]

I am surprised that it disappears when you convert.
Perhaps it's not a hot pixel after all, but a bug in C1?

In my case, when viewing at 100% magnification on any image (including with the lenscap on), the pixel is not/barely visible at exposures of 1/25 and faster (ISO 100).

At ISO 800, it's visible at anything slower than 1/60.

At exposures longer than 1 sec, it's visible at all ISO's at 100%.

At very long exposures, it becomes a white circle surrounded by a red dot.

I already have a photoshop action to remove the pixel, so that's not a big deal. If I had bought it locally, I probably would have exchanged it, but since I would have to wait 2 weeks to return it, it's probably not worth it.

And as mentioned in the link above, exchanging it does not guarantee that I would get one without atleast one hot pixel (my case, the correct term is "stuck pixel"). That poor guy tried 3 of them, all had atleast one problem pixel.

[drisley]

Here is an intersting find...

I previously had been using C1 Pro to convert my images.
So, I tried Breezebrowser, and found that the hot pixel was not as apparent, and was actually in a slightly different position.

Then, I tried Adobe Photoshop CS to do the conversion.
The hot pixel doesnt show up! Even in a 30 second exposure. Hmmm.
What conclusion would you draw from this?

[bnpndxtr]

If the pixel is very noticeable, I’d attempt to return it. I expect stuff like this in a CCD camera, but these are just too darn expensive to put up with it.

See http://photography-on-the.net/forum/viewtopic.php?p=88989#889

[drisley]

Well, after much debate, I decided to exchange the camera, mainly because the retailer (www.simonscameras.con) was gracious enough to pay for shipping the item both ways!
Also, they and Canon support both said that I should not have such a problem. If a hot pixel showed up at 2 seconds or slower, that would be another story.
Should we take odds on whether or not my replacement has something else wrong with it (or maybe more hot pixels)?

[Canuck]

I don't know if this is bad, but I was doing the test thresholds of 60 for hot pixel and 250 for dead pixel. Test findings as follows: at 30 sec, ISO 100, I have a few that are close to 250 and 33 hot pixels; ISO 3200 and 30 sec exposure, it is really bad...there are 58 hot pixels and about 8 that are really close to the 250 tolerance, including one 235. I noticed on the 3200 ISO shot about 20 and about 10 on the 100 ISO non black pixels. They were white, blue, or red. What do you think?

[perror]

I had a hot pixel on my 300D when I bought it...I ensured that I called the place I bought it within 24 hours and they agreed to change for me..although there was a 1 week wait as Canon was totally out of stock of 300D at that time here...and when I got the replacement...suprise...it was also..damaged! I had some sort of dirt or damage on the LPF..causing a black dot to appear on my pictures...Now they want to disassemble the entire thing and try to clean it..failing otherwise, they will replace the LPF assembly...sigh..

[ombra]

I'll be the one to say the obvious, and probably get flamed.

So what if you have a hot pixel? It's _EXTREMELY_ common on large CMOS, CCD and LCD arrays. In fact, it's practically impossible to find one that _doesn't_ have a hot / cold pixel.

My 300D, which I am very, very happy with, also has a hot pixel. I DEFY any of you to find the hot pixel in ANY of the pictures i have taken. (I have taken over 2000 shots with it)

You can fret and wring your hands all you like. You will never see it in an actual photograph.

Unless you make a habit of taking lots of long exposures in closed, pitch-black closets. And in that case, you need to get out more. :)

[drisley]

Ombra, at what exposure do you thinkg it's normal to find a hot pixel?
Mine shows at about 1/25 second at ISO100.
It shows at 1/60 second at ISO400.

Do you think I should just accept it since the rest of my unit is great?
Do you think chances are great that I would just get another with atleast one hot pixel?

Thanks

[ombra]

I think that the odds are very high that if you return it, the next unit will also have at least one hot pixel as well. This is not a design flaw of the Digital Rebel. It is a statistical issue with making large arrays of millions of transistors. 10D's have bad pixels, 1Ds's have them, Nikon D100's have them, my old Sony 707 had 2, my laptop has one, and I bet yours does too.
Transistors fail.
Canon image sensors have FIVE transistors per pixel. Even if the odds of failing are 1 in 100 million per transistor, that means 1/3 of the sensors start out with a bad pixel.

Hot pixels will also occur _after_ you have the camera for a while. They do not occur only at manufacturing time. So the people who return 4 cameras for having a single bad pixel might get three bad pixels next month.

Mine has a pixel that goes green at about the same exposure values as yours, but truthfully, those are not interesting exposure values. Anything below 1/60th is too slow. You will get camera shake. And even if you do take a tripod-mounted long exposure night shot, and the hot pixel is visible to you, I am certain if you show it to someone else, and tell them there is a wrong pixel, they can't find it.

Go out and enjoy your camera. Take some pictures of your friends and family. Have fun.

[drisley]

Thanks for the info.
I think I will follow your advice.
You know what's funny. I have a 19" CRT monitor (NOT LCD), and it has a dead pixel *l* (lucky it's near the corner).

I was just surprised by the hot pixel, because neither my S30 or G3 had them (atleast not on the image).

I just went to a couple prominent camera review sites and looked at a couple long exposure pictures. I found a couple hot pixels on all of their images (then again, they were 30 sec exposures). So, perhaps I'm lucky to only have 1 hp.

[Kinger]

ok maybe I am just lucky, but I have not noticed a single bad pixel in my 300d. I have had it since november, and taken plenty of shots with it. So I guess by reading this thread I should bow down to the pixel gods.

[drisley]

Perhaps.

I think every review of the camera I've seen that shows low light photos, I've spotted atleast 1 hot pixel.

Here there is a blue hot pixel in the dark area in the bottom half of the pic.
http://www.dcresource.com/reviews/canon/eos_300d-review/nightshot.jpg

In this image, I can spot atleast 3 hot pixels in the 3 second exposure (1 red and 1 white near top, and 1 blue near mid bottom)
http://www.imaging-resource.com/PRODS/EDR/FULLRES/YIMG_1012.HTM

I spot 1 blue hot pixel near the top left, and possibly another white one on the right side (could be a star) 0.7 second exposure.
http://www.imaging-resource.com/PRODS/EDR/FULLRES/YIMG_0985.HTM

There is a blue hot pixel near the center smokestack and another not so obvious red hot pixel on the right in one of the trees (really hard to see, but when compared to the other ISO shots on that site, it's easily spotted).
http://www.dpreview.com/reviews/CanonEOS300D/Samples/Night/IMG_0138.JPG

etc, etc.

However, it's not a big deal I guess. I think the only way to get rid of them would have been to use technique that canon uses in it's S and G series of cameras, where it takes a second picture of equal length, and then subtracts the noise. However, even without that, the noise on the 300d is far superior! And i used to hate waiting for that second exposure to be taken on my G3.