I just noticed this with my recent long night exposure shot....

vmax84 · 08-14-2009, 02:52 AM

little red, blue, and green dots. Why are they there? I had the shutter open for about 12 seconds (K100D with kit lens), aperture set middle of the road, ISO 200. Believe I also had the noise filter turned off.

Why the dots? Thanks.

vmax84

LeDave · 08-14-2009, 03:00 AM

Think those are called hot pixels, it usually happens for longer shutter speeds.

"Hot pixels are individual sensors on the CCD with higher than normal rates of charge leakage. They can appear as small pixel sized bright points of light on longer exposures. Every pixel on the CCD has some charge leakage, and if you expose long enough, any pixel would light up."

Hot Pixels

MJB DIGITAL · 08-14-2009, 11:04 AM

not possible that it could be ghosting or a reflection?

Jester_rm · 08-14-2009, 12:25 PM

How many dots? Any chance of posting the image?

cyy47 · 08-14-2009, 01:05 PM

I read it somewhere that you can use sensor cleanup mode to remap the sensor and fix the hot pixels. Or send the camera back for remapping if it is still under warranty. But eventually they will reappear, just a fact of life with digital sensors.

GerryL · 08-14-2009, 02:54 PM

If you posted the photo then it would have been easier to identify.

Marc Sabatella · 08-14-2009, 04:19 PM

Originally posted by cyy47

I read it somewhere that you can use sensor cleanup mode to remap the sensor and fix the hot pixels.

You wouldn't want to do that with hot pixels that only show up on long exposures, though - it's very normal for otherwise good pixels to go bad when the sensor overheats o a long exposure. Presumably the pixel mapping function takes this into account. Not sure how it actually identifies bad pixels, but it probably wouldn't notice ones that only show up on long exposures.

vmax84 · 08-14-2009, 05:20 PM

Those aren't stars or the Milky Way above the plane, but something else!!

I did have the shutter open for a long time, though.

vmax84

Barnster · 08-14-2009, 06:34 PM

Originally posted by LeDave

Think those are called hot pixels, it usually happens for longer shutter speeds.

"Hot pixels are individual sensors on the CCD with higher than normal rates of charge leakage. They can appear as small pixel sized bright points of light on longer exposures. Every pixel on the CCD has some charge leakage, and if you expose long enough, any pixel would light up."

Hot Pixels

I agree with LeDave,it sounds like 'Hot Pixals'.You can use your cloning tool on a photo editing program to remove them.

Marc Sabatella · 08-14-2009, 07:10 PM

If thaty's a 100% crop, or clsoe to it, those are hot pixels. They'd be largely invisible in the original picture at full screne size or on a 4x6 print. If that's not a crop, they are probably cluster of hot pixels, and that would be most unfortunate if it happens often.

vmax84 · 08-14-2009, 07:22 PM

Originally posted by Marc Sabatella

If thaty's a 100% crop, or clsoe to it, those are hot pixels. They'd be largely invisible in the original picture at full screne size or on a 4x6 print. If that's not a crop, they are probably cluster of hot pixels, and that would be most unfortunate if it happens often.

You're right, I took the picture, shot at it's largest setting, and cropped it, or took a "chunk" of the picture. I never noticed "the pretty dots" until I looked at the picture at its largest setting.

I guess I shouldn't sweat it, then.

Thanks a lot.

vmax84

MJB DIGITAL · 08-15-2009, 09:53 AM

In a world where camera=terrorist, how did you manage to lug a tripod and do a long exposure of an airplane?

Ninja?

vmax84 · 08-15-2009, 10:11 AM

Originally posted by MJB DIGITAL

In a world where camera=terrorist, how did you manage to lug a tripod and do a long exposure of an airplane?

Ninja?

I run around in one of these goobers, so I have access to the ramp. I am, however, somewhat discreet on where I set my camera up. Had it set up just outside our building. There are security cameras all over the place at these places and who knows who's watching you watch others. :-)

vmax84

vmax84 · 08-15-2009, 10:18 AM

Droning along at 4000 feet to stay out of the headwinds.

vmax84

LeDave · 08-15-2009, 10:51 AM

Wow that's awesome vmax84, so you work for FedEx as a pilot I suppose?

08-14-2009, 02:52 AM	#1
vmax84 Veteran Member Join Date: Feb 2008 Location: Michigan Posts: 307	I just noticed this with my recent long night exposure shot.... little red, blue, and green dots. Why are they there? I had the shutter open for about 12 seconds (K100D with kit lens), aperture set middle of the road, ISO 200. Believe I also had the noise filter turned off. Why the dots? Thanks. vmax84

08-15-2009, 10:11 AM	#13
vmax84 Veteran Member Join Date: Feb 2008 Location: Michigan Posts: 307 Original Poster	Originally posted by MJB DIGITAL In a world where camera=terrorist, how did you manage to lug a tripod and do a long exposure of an airplane? Ninja? I run around in one of these goobers, so I have access to the ramp. I am, however, somewhat discreet on where I set my camera up. Had it set up just outside our building. There are security cameras all over the place at these places and who knows who's watching you watch others. :-) vmax84 Last edited by Damn Brit; 08-17-2009 at 03:38 PM. Reason: Added imgwide tags

08-15-2009, 10:18 AM	#14
vmax84 Veteran Member Join Date: Feb 2008 Location: Michigan Posts: 307 Original Poster	Droning along at 4000 feet to stay out of the headwinds. vmax84 Last edited by Damn Brit; 08-17-2009 at 03:38 PM. Reason: Added imgwide tags

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08-14-2009, 03:00 AM	#2
LeDave Veteran Member Join Date: Jun 2009 Location: Minneapolis - St. Paul Photos: Gallery Posts: 3,067	Think those are called hot pixels, it usually happens for longer shutter speeds. "Hot pixels are individual sensors on the CCD with higher than normal rates of charge leakage. They can appear as small pixel sized bright points of light on longer exposures. Every pixel on the CCD has some charge leakage, and if you expose long enough, any pixel would light up." Hot Pixels

08-14-2009, 11:04 AM	#3
MJB DIGITAL Veteran Member Join Date: Jul 2007 Location: st. louis Posts: 1,170	not possible that it could be ghosting or a reflection?

08-14-2009, 12:25 PM	#4
Jester_rm Senior Member Join Date: Jun 2007 Location: Redmond, Oregon Photos: Gallery Posts: 228	How many dots? Any chance of posting the image?

08-14-2009, 01:05 PM	#5
cyy47 Senior Member Join Date: Jun 2009 Location: Boston, MA Photos: Gallery \| Albums Posts: 157	I read it somewhere that you can use sensor cleanup mode to remap the sensor and fix the hot pixels. Or send the camera back for remapping if it is still under warranty. But eventually they will reappear, just a fact of life with digital sensors.

08-14-2009, 02:54 PM	#6
GerryL Veteran Member Join Date: Jan 2009 Location: CA Posts: 2,731	If you posted the photo then it would have been easier to identify.

08-14-2009, 04:19 PM	#7
Marc Sabatella Veteran Member Join Date: Sep 2006 Location: Denver, CO Photos: Gallery Posts: 10,685	Originally posted by cyy47 I read it somewhere that you can use sensor cleanup mode to remap the sensor and fix the hot pixels. You wouldn't want to do that with hot pixels that only show up on long exposures, though - it's very normal for otherwise good pixels to go bad when the sensor overheats o a long exposure. Presumably the pixel mapping function takes this into account. Not sure how it actually identifies bad pixels, but it probably wouldn't notice ones that only show up on long exposures.

08-14-2009, 05:20 PM	#8
vmax84 Veteran Member Join Date: Feb 2008 Location: Michigan Posts: 307 Original Poster	Those aren't stars or the Milky Way above the plane, but something else!! I did have the shutter open for a long time, though. vmax84

08-14-2009, 06:34 PM	#9
Barnster Veteran Member Join Date: Jun 2009 Location: Mid North Coast,Australia Photos: Gallery Posts: 1,016	Originally posted by LeDave Think those are called hot pixels, it usually happens for longer shutter speeds. "Hot pixels are individual sensors on the CCD with higher than normal rates of charge leakage. They can appear as small pixel sized bright points of light on longer exposures. Every pixel on the CCD has some charge leakage, and if you expose long enough, any pixel would light up." Hot Pixels I agree with LeDave,it sounds like 'Hot Pixals'.You can use your cloning tool on a photo editing program to remove them.

08-14-2009, 07:10 PM	#10
Marc Sabatella Veteran Member Join Date: Sep 2006 Location: Denver, CO Photos: Gallery Posts: 10,685	If thaty's a 100% crop, or clsoe to it, those are hot pixels. They'd be largely invisible in the original picture at full screne size or on a 4x6 print. If that's not a crop, they are probably cluster of hot pixels, and that would be most unfortunate if it happens often.

08-14-2009, 07:22 PM	#11
vmax84 Veteran Member Join Date: Feb 2008 Location: Michigan Posts: 307 Original Poster	Originally posted by Marc Sabatella If thaty's a 100% crop, or clsoe to it, those are hot pixels. They'd be largely invisible in the original picture at full screne size or on a 4x6 print. If that's not a crop, they are probably cluster of hot pixels, and that would be most unfortunate if it happens often. You're right, I took the picture, shot at it's largest setting, and cropped it, or took a "chunk" of the picture. I never noticed "the pretty dots" until I looked at the picture at its largest setting. I guess I shouldn't sweat it, then. Thanks a lot. vmax84

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08-15-2009, 09:53 AM	#12
MJB DIGITAL Veteran Member Join Date: Jul 2007 Location: st. louis Posts: 1,170	In a world where camera=terrorist, how did you manage to lug a tripod and do a long exposure of an airplane? Ninja?

08-15-2009, 10:51 AM	#15
LeDave Veteran Member Join Date: Jun 2009 Location: Minneapolis - St. Paul Photos: Gallery Posts: 3,067	Wow that's awesome vmax84, so you work for FedEx as a pilot I suppose?