Dots in pictures

Hoky · 28th October 2006

I took a long exposed picture of a white background. And I saw some purplish and white dots.

These don't look like dust to me.
Are these dead pixels?

How much is it to replace the CMOS sensor if I were to send to Canon.

sumball · 28th October 2006

Could be just the noise.

Post your photo. Tell us your camera and setting used to take the photo.

+evenstar · 28th October 2006

npnt..........

Hoky · 28th October 2006

Originally Posted by +evenstar

npnt..........

What's that???

Hoky · 28th October 2006

Originally Posted by sumball

Could be just the noise.

Post your photo. Tell us your camera and setting used to take the photo.

I deleted it off as I used it to trace dust in my sensor only.
Will post tomorrow with EXIF data.

Virgo · 28th October 2006

It could be just noise or hot/dead pixels.

irrelevance · 28th October 2006

probably hot pixels if its only on long exposures

Hoky · 29th October 2006

Originally Posted by irrelevance

probably hot pixels if its only on long exposures

Thanks for the info.
Just read up on hotpixels and I guess this might be it... My exposures are usually 25 ~ 30s for trace detection. I get pink / purplish / white spots... the symptoms of hot pixels..

Hobbes234 · 29th October 2006

Originally Posted by +evenstar

npnt..........

No picture no talk...
English: Please post a picture

looks like u frequent EDMW.

+evenstar · 29th October 2006

Originally Posted by Hobbes234

No picture no talk...
English: Please post a picture

looks like u frequent EDMW.

common term used in CS...

loneoceans · 30th October 2006

Originally Posted by Hoky

I took a long exposed picture of a white background. And I saw some purplish and white dots.

These don't look like dust to me.
Are these dead pixels?

How much is it to replace the CMOS sensor if I were to send to Canon.

Hey,

I hope your camera's still under warranty. I got a 350D just a while ago and all was ok except when I took some long exposure shots, which to my horror had a -lot- of white dots. and tiny crosses.

So I sent it to canon and they said they replaced the whole imaging circuit board with sensor for me, works beautiful now

.

Canon service not too bad so far.

Hoky · 31st October 2006

Originally Posted by loneoceans

Hey,

I hope your camera's still under warranty. I got a 350D just a while ago and all was ok except when I took some long exposure shots, which to my horror had a -lot- of white dots. and tiny crosses.

So I sent it to canon and they said they replaced the whole imaging circuit board with sensor for me, works beautiful now .

Canon service not too bad so far.

Duh... warranty over quite some time ago already.
I guess no choice, have to live with it.
Other than IR, I don't usually use long exposures of more than 30secs.. So that's ok.

Hoky · 31st October 2006

Here's pictures... come talk...

Taken 2 sec ISO 100 with len cap on.

Cropped 200% of selected area.

See the white little spots?

Taken 60 secs ISO 100 of white background.

Cropped 200% of selected area.

Hoky · 31st October 2006

Like seeing stars... heehee..

sumball · 31st October 2006

Hot pixels to me.

donkuok · 1st November 2006

yup..those r hotpixel...just get down to CSC to remap it

+evenstar · 1st November 2006

Originally Posted by donkuok

yup..those r hotpixel...just get down to CSC to remap it

don't think he can do that. note the shutter speeds at which he is shooting: 2sec and 60sec respectively.

hot pixels are inevitable. even a 1-series has hot piexels at that kind of shutter speed

Hoky · 1st November 2006

Originally Posted by +evenstar

don't think he can do that. note the shutter speeds at which he is shooting: 2sec and 60sec respectively.

hot pixels are inevitable. even a 1-series has hot piexels at that kind of shutter speed

Newbie about hot pixel here... 2 sec got hot pixel also inevitable???

Moonstone · 1st November 2006

Confirm hot pixel. Don't think Canon will do anything about it. You may have to Photoshop it yourself when you see it during long exposure.

+evenstar · 1st November 2006

Originally Posted by Hoky

Newbie about hot pixel here... 2 sec got hot pixel also inevitable???

yup..

28th October 2006	#1
Hoky Member Join Date: Mar 2004 Location: Singapore Posts: 1,186	Dots in pictures I took a long exposed picture of a white background. And I saw some purplish and white dots. These don't look like dust to me. Are these dead pixels? How much is it to replace the CMOS sensor if I were to send to Canon.

28th October 2006	#2
sumball Senior Member Join Date: Jul 2003 Posts: 4,224	Re: Dots in pictures Could be just the noise. Post your photo. Tell us your camera and setting used to take the photo.

28th October 2006	#3
+evenstar Senior Member Join Date: Jan 2004 Location: Singapore Posts: 5,452	Re: Dots in pictures npnt.......... __________________ the SEARCH FUNCTION is there for a reason. USE IT!

28th October 2006	#6
Virgo Senior Member Join Date: Dec 2003 Location: West of Singapore Posts: 4,559	Re: Dots in pictures It could be just noise or hot/dead pixels. __________________ Kind Regards My Picture Website

28th October 2006	#7
irrelevance Member Join Date: Oct 2006 Location: Melbourne, Australia Posts: 70	Re: Dots in pictures probably hot pixels if its only on long exposures

31st October 2006	#13
Hoky Member Join Date: Mar 2004 Location: Singapore Posts: 1,186	Re: Dots in pictures Here's pictures... come talk... Taken 2 sec ISO 100 with len cap on. Cropped 200% of selected area. See the white little spots? Taken 60 secs ISO 100 of white background. Cropped 200% of selected area.

31st October 2006	#14
Hoky Member Join Date: Mar 2004 Location: Singapore Posts: 1,186	Re: Dots in pictures Like seeing stars... heehee..

31st October 2006	#15
sumball Senior Member Join Date: Jul 2003 Posts: 4,224	Re: Dots in pictures Hot pixels to me.

1st November 2006	#16
donkuok Member Join Date: Oct 2004 Location: Perth, Australia Posts: 902	Re: Dots in pictures yup..those r hotpixel...just get down to CSC to remap it __________________ Canon EOS 40D + Batt grip

1st November 2006	#19
Moonstone Member Join Date: Sep 2004 Location: Woodlands Posts: 464	Re: Dots in pictures Confirm hot pixel. Don't think Canon will do anything about it. You may have to Photoshop it yourself when you see it during long exposure.