30D Hot Pixel, take it back?

[boink]

a few days ago, I was doing tests for dead/hot pixels on my new 30D. Well, I found that there is one hot pixel that shows up at long exposures. At first, I thought... well, it's only one pixel and it won't matter that much. And how often do I take exposures that long? No worries.

Well, friday night, there was a bunch of people out in the middle of the street hooping and hollering for no reason. I thought it would be fun to take candids of them from my window =P

anyways, I was taking shots at both ISO 1600 and 3200 (I must say, the lack of noise with auto-noise reduction on is AMAZING). But then I noticed a big white spot, about 5x5 pixels... It's the hot spot. At high ISOs, the spot starts changing things around it too.

So, the question is... should I take it back because of this? I'm starting to think... yes. It's worth the hassle to make sure I get one that doesn't have any problems at all. But who knows if they'll even have any more 30Ds in stock?

I suppose if they don't, I can make it known to get another one on hold for me, then swap it once it comes in?

It came from Norman Camera btw (the actual store, not the website. It's just down the road from me.)

[sboerup]

I would, after paying all that money for it, now way would I want a hot pixel on it. Canon should replace that, if not, then Canon is lame. Call them up.

[jbkalla]

Make sure you print a couple pics to show it doesn't change position or anything. Then bring it back with the proof.

[Tsmith]

Dilemma is how do you know if the the replacement might have more. Have you done testing with the lens cap on and used the Pixel Test app.?

[boink]

Dilemma is how do you know if the the replacement might have more. Have you done testing with the lens cap on and used the Pixel Test app.?
Yes, I have. I did several lens cap tests. The pixel shows up same exact spot on every one. 10", 15", 30". Just gets brighter and brighter till it's pretty much white at 30".

[Tsmith]

How many Hot Pixels did the test show?

[boink]

only one single one. It's near the bottom right. It's just annoying, though an easy fix if I kept the camera.

but I would much rather there was NOTHING.

[Tsmith]

Theres a difference in Hot and Dead Pixels ... in long exposures Hot Pixels can be more numerous.

[::John::]

How visible is it? I mean, how are you seeing it? Are you zooming in to your picture? If so, what resolution does it start to become visible enough to be a problem.

I was reading elsewhere that it is not uncommon to find the occassional hot or dead pixel. Afterall, 25 affected out of 8.2 million is probably within the bounds of probability.

If you print that picture, does it look like a blob in the corner?

[boink]

I'll show you...

Let me take one.

EDIT: for fun, I just did ISO 3200 with 30" exposure at the lens cap... 29 hot pixels and crazy noise.

let's put it back to ISO 100..

[boink]

http://kniob.net/useless/hotpixel1.jpg

at ISO 100, 30" exposure. f/3.5. 100% crop

this is yesterday, what I was talking about.

http://kniob.net/useless/hotpixel2.jpg

ISO 3200, 1/60" exposure, f/4.0. 100% crop.

that big white spot is annoying. very annoying.

[Tsmith]

29 Hot or 29 Dead?

[boink]

Hot, Hot, Hot. I even wrote it in the title. Hot Hot Hot Hot Hot. I never once mentioned a dead pixel.

and those weren't hot, it was just picking up the noise. Since I had ISO3200 at 30". Noisy as hell.

[::John::]

The image size for a 30D on L is around 3504x2336

At 100% a print of that would produce a document 48"x32"

At that size, that dot would be the size you have produced above at 100%

You need to work this out in your own mind, I guess, but if it was me that spot wouldn't worry me unless I was going to be printing pictures 4 foot wide.

[boink]

look at this. Resized to 900x600.

http://kniob.net/useless/hotpixel3.jpg

stands out like a sore thumb...

[Tsmith]

Well just to make you feel better I just did an ISO 100 30" exposure and came up with 1 Dead Pixels and 10 Hot Pixels ... but for the life of me I don't see it at 1280x1024 on my monitor. I can lower the exposure time a little and everything is 0.

+ clone stamp and that can be easily fixed.

[calicokat]

How do you test for it, take a picture at ISO 3200 for 30" at F/4.0 with the lens cap on??? I tried it with my 30D and there is nothing unless you zoom in all the way on the camera and then there are a few strange spots and one very small white dot. What does this mean??? This thread has made me wonder, so I tried it. At ISO 100, there is nothing at all

[calicokat]

Well just to make you feel better I just did an ISO 100 30" exposure and came up with 1 Dead Pixels and 10 Hot Pixels ... but for the life of me I don't see it at 1280x1024 on my monitor. I can lower the exposure time a little and everything is 0.

+ clone stamp and that can be easily fixed.

Totally confused, what does a hot pixel and dead pixel look like. And do they show up in regular everyday photos or prints up to 16x20. Thanks for the education on this :)

[Tsmith]

Read this: http://www.imaging-resource.com/ARTS/HOT/HOT.HTM

[calicokat]

Read this: http://www.imaging-resource.com/ARTS/HOT/HOT.HTM

Thank you, explains alot. What about a dead pixel, whats that going to look like??

[Tsmith]

Dead Pixels are generally a fixated Red Dot that shows up all the time no mater what.

[calicokat]

Dead Pixels are generally a fixated Red Dot that shows up all the time no mater what.

Oh, good thing I see no red dots. Thanks for all the info. My 30D had all kinds of interesting spots at ISO 3200 at 30" and nothing at ISO 100 at 30"

[Tsmith]

Oh, good thing I see no red dots. Thanks for all the info. My 30D had all kinds of interesting spots at ISO 3200 at 30" and nothing at ISO 100 at 30"

Mine too and its a normal occurence ... ;)

[calicokat]

So, based on my new found knowledge, thanks Bluedog XT, I would say there is nothing wrong with your 30D, keep it. Seems like it happens to all 30D's.

[kisielk]

Hot pixels are just a fact of life with the digital sensors. Trading your camera in for a different one won't change anything other than the position of the pixels. if you have a decent RAW converter it should remove the hot pixels (replace with data from surrounding pixels). Also, I've been told you can send your camera in to Canon and have them map out the pixels in firmware to have the camera adjust for it. I guess this is more useful if you're shooting JPEG and seeing them show up. Anyway, it's always correctable in post processing, so not really a big deal.

[Tsmith]

Hot pixels are just a fact of life with the digital sensors. Trading your camera in for a different one won't change anything other than the position of the pixels. if you have a decent RAW converter it should remove the hot pixels (replace with data from surrounding pixels). Also, I've been told you can send your camera in to Canon and have them map out the pixels in firmware to have the camera adjust for it. I guess this is more useful if you're shooting JPEG and seeing them show up. Anyway, it's always correctable in post processing, so not really a big deal.

Very well said for a new member _ welcome to POTN.

[Jack W.]

I never tested my 20D, and won't likely test my 30D.
In real world use, I've never seen any pixel problems with my 20D, and so far none with my 30D.
Both cameras likely have a pixel or two (or three) that are hot/dead, but they don't show up in the shots I take. If they should, takes but a few seconds to clone out.
My first digital camera was a G3. It has one hot pink pixel, almost centered, which shows in a lot of shots. It was there right out of the box, but I decided not to exchange it or bother sending it for remapping. Too easy to correct in Photoshop, etc. to worry about.

Jack

[nitsch]

Guys stop stressing over this!!! :D

If you do a sensor clean on the 30D it remaps any hot pixels at the same time. I had one one my new body, I tried it and it works 100%. Great function!

[JBF]

Canon actually told me that .01 percent of all pixels on a 20D or 30D is an acceptable number on those cameras for hot pixels. So I guess that 82 hot pixels would be ok. I had on my 20D about 140 at 30 Second exposures with ISO set to 1600. So I doubt that even if you got a new camera, it would be hot pixel free at high ISO's and long exposures.

[Tsmith]

Guys stop stressing over this!!! :D

If you do a sensor clean on the 30D it remaps any hot pixels at the same time. I had one one my new body, I tried it and it works 100%. Great function!

Do you have proof of Canon specifications on this with the 30D? I Googled and found some user report of this but no substantial data to back it up.

[nitsch]

Do you have proof of Canon specifications on this with the 30D? I Googled and found some user report of this but no substantial data to back it up.

Can't find any official documentation but I tried it on my 30D and the pixel which I could get to show up everytime in exactly the same place at ISO1600 approx 5 sec exposure (with lens cap on) is now completely gone after a sensor clean. That's enough proof for me!

[Tsmith]

That could have been results of temperature. I'm not saying it doesn't but without official documentation on this feature (which would be great) I can't buy it doing this.

[nitsch]

That could have been results of temperature. I'm not saying it doesn't but without official documentation on this feature (which would be great) I can't buy it doing this.

Hmm I doubt it. What temperature difference would there be doing a test shot, doing a quick sensor clean, then doing another test shot... all within the space of say 2 or 3 minutes?

Try it on yours that's all I can suggest.

[summerwind4]

Guys stop stressing over this!!! :D

If you do a sensor clean on the 30D it remaps any hot pixels at the same time. I had one one my new body, I tried it and it works 100%. Great function!

i just have to jump on this as it is true, something is going on when putting the 30D and the 5D into "sensor clean" mode.........my new 30D shows no dead/hot pixels when testing up to 6secs and using the Starzen software, but when viewing the black frames i saw a blue dot clear as a bell. ran the sensor clean as a last resort to exchange, and it's gone, and have checked it twice since and still gone............same happened with my 5D.

[thebrewer]

Does the 20D have a similar function? Between weddings, travel and other events, it it hard to send this thing in for service. Canon is quoting 10 business days turnaround.

Rich

[summerwind4]

try it, you can't lose anything right.
my 20D had no hot pixels after 3 thousand shots even up to 6 seconds, iso 400.............sold it as i can't justify keeping 3 DSLR's, not to mention i needed the money for a new Dell 2405FPW wide panel.

[deezeljuice]

I just bought a 20D and found I had a hot pixel on the LCD. It didn't affect the photos of course, but it was annoying as heck. I called Digital Fofo Club and told them, sent it right back for another, no questions asked. I haven't heard about a hot pixel on the LCD, anyone else had that problem?

[nater]

Can't find any official documentation but I tried it on my 30D and the pixel which I could get to show up everytime in exactly the same place at ISO1600 approx 5 sec exposure (with lens cap on) is now completely gone after a sensor clean. That's enough proof for me!

So perhaps your hot pixels were caused by dust & dirt on your sensor? There's no magical pixel-remapping algorithm that goes on when you go into Sensor Cleaning mode. The mirror flips up, and waits for you to turn off the camera... that's it.

[summerwind4]

So perhaps your hot pixels were caused by dust & dirt on your sensor? There's no magical pixel-remapping algorithm that goes on when you go into Sensor Cleaning mode. The mirror flips up, and waits for you to turn off the camera... that's it.

where is the documentation for your claim here?
thought so.

for the record, those of us who have had HOT (read HOT, not dust) pixels dissappear, have indeed verified what a HOT pixel looks like.

please educate yourself before making assumptions.:rolleyes:

[nitsch]

So perhaps your hot pixels were caused by dust & dirt on your sensor? There's no magical pixel-remapping algorithm that goes on when you go into Sensor Cleaning mode. The mirror flips up, and waits for you to turn off the camera... that's it.

Sorry Nater, I was sceptical too but having tried this for myself I can say with the utmost confidence that you're way off here.

[boink]

Hot pixels are just a fact of life with the digital sensors. Trading your camera in for a different one won't change anything other than the position of the pixels. if you have a decent RAW converter it should remove the hot pixels (replace with data from surrounding pixels). Also, I've been told you can send your camera in to Canon and have them map out the pixels in firmware to have the camera adjust for it. I guess this is more useful if you're shooting JPEG and seeing them show up. Anyway, it's always correctable in post processing, so not really a big deal.
good point on the RAW. I'm currently shooting RAW+Jpeg, and just using Jpeg until CS2 gets an update to edit 30D's raw files.

I'm running the sensor cleaning now... I don't know what I have to do... I heard the shutter pop open, and it's just sitting there now. haha. I'll just leave it for a few seconds and shut it off...

I don't know why I'm writing this like a story that you can all read in real time...

letting sensor clean run didn't fix it. How do I do this? I'll do a google search and post results if I find anything... otherwise, someone tell me.