hot pixels

[felix21685]

i seem to have at least 1 hot pixel,

i guess i could have more..
how many do you guys have and do you just deal with them or send em back and try a new one.

i bought this camera from 17th street photo.
thanks

[felix21685]

i was also thinking about this a while ago..

and is there any way you can tell the camera to have the hot pixel be automatically be black on long exposures? wouldnt that be nice ?

[tim]

On your LCD or in your sensor? Either way i'd return it myself.

There is a custom function on the LCD to reduce noise on long exposures, but i'm not sure if it'd deal with hot pixels.

[felix21685]

its on the sensor.

you can return it and they wont mind? even with just 1 ? couldnt it be worse?
i mean yes i spent 1000 bucks on a camera i kind of want it to be clear of hot pixels on the sensor at least you know ?

edit: by the way its a blue pixel same spot every time long exposures mostly

[Raj]

Felix, can you be more specific as to when you see this hot pixel ? like low iso/high iso & @ what shutter speed ? Depending on these factors hot pixels may be bad/acceptable.

You can enable long exposure noise reduction via custom function 2. This will take care of hot pixels for exposures greater than/equal to 1 sec.

[tim]

Does it show up on a 1/10 exposure? Or a 10 sec exposure? If it only appeared on exposures > 1sec I probably wouldn't worry myself. Canon can remap the sensor so it just ignores that pixel if you send it to them, but since it's new i'd personally return it to where you got it from.

[felix21685]

seems like i get them when SS is over a few seconds.. low iso 100& 200
plus i dont like to wait 30 seconds on a 30 sec capture..i would like to think that a 1000 dollar camera can somehow get rid of them if they are there a little faster..you know

now that i take a close look there are 4-5 hot pixels on a long exposure image. some blue some pinkish red

edit : even at 1sec and 2 sec exposures you can tell theres at least 1 hot pixel

do you guys have any of these on your rebel xt's or 20D?

[tim]

I don't have any hot pixels on my 20D, at least none that i've noticed. I do a little long exposure stuff for macro, but I probably would have noticed a hot pixel.

Best thing for you to do is call where you bought the camera and ask for an exchange. Worst they can do is say no.

[lmelendez]

I found 2 hot pixels in my 20D the first day I got it (iso > 800, exposures > 20sec). To be honest with you, I didn't care. Sending the camera back to BH, plus waiting for the replacement, plus hoping that the new one will not have 3 or more.... I thought I better get out and take picture and PS the hot pixels out when needed.

I've taken more than 1000 pictures so far. One 2 of them required 2 seconds of PS to remove the hot pixels (two night shots @ 30 sec).

I don't know what are the chances of getting a camera with hot pixels. I thought I read somewhere in the manual that hot pixels are not considered a defect... but don't believe just yet... I couldn't find in the manual (maybe it was the 300D??? not sure). Anyway... to me, 2 pixels out of 118,000 are not worth going to all the trouble of exchanging the camera.

Leo.

[gasrocks]

I have a copy of a free program called - deadpixeltest. Basically you take a pix with lens cap on. Try it out.

[mbze430]

just tried the program out

damn, I have 1 hot pixel after moving the threshold to 4. But I can barely even see it at 1600% zoom. Shot at 100ISO 30sec. with lens cap as suggested by the manual. It has a luminance of 8 for this hot pixel.

I am calling Canon on monday!

[felix21685]

mbze430, please let us know with what canon tells you i emailed them and still waiting to hear back from them

[Raj]

I think you are bothering yourself unnecessarily. Also I am quite sure canon wont replace it for 1 hot pixel. They will just remap it to adjecent pixels value.

& I am sure if you test with long exposure noise reduction on, you wont see that 1 pixel either.

I have some hot pixels when I shoot really long but they are curtailed by NR.
This is what I got as best I remember
2 hot pixels at iso100 at 30 sec exposure
4 hot pixels at iso200 at 30 sec exposure
6 hot pixels at iso400 at 30 sec exposure
6 hot pixels at iso800 at 30 sec exposure

When I turned NR on I didnt get a single hot pixel upto 1so800 & 30 sec exposure. So why should I worry ??

I dnt bother testing any higher because I dont see a situation where I will use iso 1600/3200 for very long exposures

Even you you get a replacement, there is no gurantee you would not get a worst one.

just tried the program out

damn, I have 1 hot pixel after moving the threshold to 4. But I can barely even see it at 1600% zoom. Shot at 100ISO 30sec. with lens cap as suggested by the manual. It has a luminance of 8 for this hot pixel.

I am calling Canon on monday!

[Raj]

Sorry but $1000 is not any benchmark. Hot pixels are function of exposure time, iso & ambient temperature. They can be found on most digital camera sensors in one condition or other.



seems like i get them when SS is over a few seconds.. low iso 100& 200
plus i dont like to wait 30 seconds on a 30 sec capture..i would like to think that a 1000 dollar camera can somehow get rid of them if they are there a little faster..you know

now that i take a close look there are 4-5 hot pixels on a long exposure image. some blue some pinkish red

edit : even at 1sec and 2 sec exposures you can tell theres at least 1 hot pixel

do you guys have any of these on your rebel xt's or 20D?

[Bob_A]

I have 8 hot pixels varying in luminance from 62 to 114 when I do the test using Iso 100 and 30s (without long exposure noise reduction). I left the threshold at the default of 60. if I set the threshold to 4 I get a list of 100 hot pixels.

At 2s exposure and Iso 200 I don't see any hot pixels at the default threshold (61 at a threshold of 4).

Is this normal? Should I be concerned? :) I'd be interested in hearing what Canon's quality control standard is (although I don't think I would be in a panic to take my camera in for repair even if mine doesn't "pass").


Edit:

With the Iso 100, 30s test and threshold at 60 my hot pixels dropped to zero with long exposure NR turned on (still got 100 with a threshold of 4, 19 with a threshold of 10).


Bob

[mbze430]

LOL, I was being sarcastic! I wouldnt' call Canon for 1 pixel. My noise reduction is set to Off for anyone that is interested. I would think the quality of the 1-Series should be as that.

[felix21685]

i did the actualy hot pixel test..the little freeware program and it came up with 15 and once with 29 WITH noise reduction ON !!!
something wrong with that

[Wazza]

Maybe coz the noise reduction smooths objects out?

Myself, I had a red hot pixel, which is in one spot. It actually looks a little larger than 1 pixel. Maybe 2x3.. Or just a small red glow from it!

I only noticed it after I had already done 12,000 shots in several weeks. I doubt they would beleive me. However I did have some night shots done in my first 3,000 which proved it was there from the beginning. As of today, 3 months since getting camera, just past 25,000 shots. Guess the 20D is quite durable. I'll try not to reach 100,000 in a year. My aim is to keep the camera till end of next year.

[Raj]

i did the actualy hot pixel test..the little freeware program and it came up with 15 and once with 29 WITH noise reduction ON !!!
something wrong with that

Definately seems wrong if NR was on but felix you need to be more clear what you are talking about, what iso ? how long exposure ?? did you changed thershold ?

[felix21685]

it was 30 seconds i did iso 100,400,800,1600
i got 2 on iso 100 or so
i got 6 iso 400 i got 14 iso 800
i got 29 iso 1600

with noise redutcion on

[felix21685]

i got an email back from canon saying i would have to send it in..

ill call them to get a more specific answer..

i figured ill wait till after the F1 race.

[Andy_T]

it was 30 seconds i did iso 100,400,800,1600
i got 2 on iso 100 or so
i got 6 iso 400 i got 14 iso 800
i got 29 iso 1600


Sounds normal for ISO 1600 ... wouldn't really give it too much consideration.

If you do a 30 seconds exposition on ISO 1600, you have night vision goggles instead of a camera...

Best regards,
Andy

[Raj]

If you do a 30 seconds exposition on ISO 1600, you have night vision goggles instead of a camera...

Best regards,
Andy

LOL ;)

[Raj]

it was 30 seconds i did iso 100,400,800,1600
i got 2 on iso 100 or so
i got 6 iso 400 i got 14 iso 800
i got 29 iso 1600

with noise redutcion on

These results are not bad but I would have expected NR to work better. I hope you tested with default thershold of 60 or whatever it is.

Let us know what canon says.

[Persian-Rice]

Without getting too technical, every camera has hot pixels, I will repeat myself, every camera.
You can raplace it all you want, but they all have them.

A stuck pixel is somewhat different and is curable, they wont replace it, they will repare it, unless its still under the store return policy period. To be honest, I have had stuck pixels go away over a period of time. There will be along turnaround period, so if you dont need the camera, send it in. If its just some random pixels, then don't bother.

[felix21685]

thanks for the help,

i plan on keeping it and then after the F1 race in june i will maybe send it in.

i also am doing a focus test tonight ..seems like my pictures arent as sharp as they are supposed to be..

granted i have cheaper lenses than most of you so i will have to see