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Small red dot on night pictures

 
 
Joshua Beall
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Posts: n/a
 
      07-06-2004
Hi everyone,

I have noticed a small red dot on pretty much all the night pictures I have
shot. It happens with both my 28-80 and my 75-300 lenses, so I do not think
it is a lense problem. Also, I do not notice this shot except during night
or dark shooting conditions. Even indoor lighting with no flash does not
reveal this dot.

I am shooting a Canon EOS 10D. Any ideas on what could cause this? What
are the chances that there is a problem with the sensor? Could it be dust
on the sensor? I have thought about opening the shutter and shining a
flashlight on the sensor to see if I can see anything, but I do not want to
damage the sensor by shining a bright light on it for an extended period of
time. Should I be worried about this, or is a flashlight not bright enough
to cause any harm?

Here is a crop of an image that shows the dot:
http://joshbeall.com/personal/redDot.jpg (41k)

Here is the original shot. The dot is at (2093,1472):
http://joshbeall.com/personal/moon.jpg (1.1m)

Thoughts?

Sincerely,
-Josh


 
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Ed Ruf
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Posts: n/a
 
      07-06-2004
On Tue, 06 Jul 2004 15:16:50 GMT, in rec.photo.digital "Joshua Beall"
<(E-Mail Removed)> wrote:

>Hi everyone,
>
>I have noticed a small red dot on pretty much all the night pictures I have
>shot. It happens with both my 28-80 and my 75-300 lenses, so I do not think
>it is a lense problem. Also, I do not notice this shot except during night
>or dark shooting conditions. Even indoor lighting with no flash does not
>reveal this dot.
>
>I am shooting a Canon EOS 10D. Any ideas on what could cause this? What
>are the chances that there is a problem with the sensor? Could it be dust
>on the sensor? I have thought about opening the shutter and shining a
>flashlight on the sensor to see if I can see anything, but I do not want to
>damage the sensor by shining a bright light on it for an extended period of
>time. Should I be worried about this, or is a flashlight not bright enough
>to cause any harm?
>
>Here is a crop of an image that shows the dot:
>http://joshbeall.com/personal/redDot.jpg (41k)
>
>Here is the original shot. The dot is at (2093,1472):
>http://joshbeall.com/personal/moon.jpg (1.1m)


Stuck pixel. If still under warranty send it in to have it mapped out.
Maybe someone else can point to a user utility to do such as is
available for some other makes/models.
__________________________________________________ ______
Ed Ruf Lifetime AMA# 344007 ((E-Mail Removed))
See images taken with my CP-990 and 5700 at
http://EdwardGRuf.com
 
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Joshua Beall
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Posts: n/a
 
      07-06-2004
"Ed Ruf" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> Stuck pixel. If still under warranty send it in to have it mapped out.
> Maybe someone else can point to a user utility to do such as is
> available for some other makes/models.


Any idea why it would only show up on night shots?


 
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marlin
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      07-06-2004
You have a hot pixel. This happens when a CCD is exposed for a long time.
Some pixels (in your case 1) expose fast, so when you select a slow shutter
speed, they show up as red dots. I'm kinda surprised about this in an E10D.
How old is the camera? If it's within 1 year of purchasing (i.e. under
warranty) you can send it to canon to remap the CCD.
Richard
"Joshua Beall" <(E-Mail Removed)> wrote in message
news:CnzGc.24984$(E-Mail Removed)...
> Hi everyone,
>
> I have noticed a small red dot on pretty much all the night pictures I

have
> shot. It happens with both my 28-80 and my 75-300 lenses, so I do not

think
> it is a lense problem. Also, I do not notice this shot except during

night
> or dark shooting conditions. Even indoor lighting with no flash does not
> reveal this dot.
>
> I am shooting a Canon EOS 10D. Any ideas on what could cause this? What
> are the chances that there is a problem with the sensor? Could it be dust
> on the sensor? I have thought about opening the shutter and shining a
> flashlight on the sensor to see if I can see anything, but I do not want

to
> damage the sensor by shining a bright light on it for an extended period

of
> time. Should I be worried about this, or is a flashlight not bright

enough
> to cause any harm?
>
> Here is a crop of an image that shows the dot:
> http://joshbeall.com/personal/redDot.jpg (41k)
>
> Here is the original shot. The dot is at (2093,1472):
> http://joshbeall.com/personal/moon.jpg (1.1m)
>
> Thoughts?
>
> Sincerely,
> -Josh
>
>



 
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HooDooWitch
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Posts: n/a
 
      07-06-2004
"Joshua Beall" <(E-Mail Removed)> somehow
managed to post:

>"Ed Ruf" <(E-Mail Removed)> wrote in message
>news:(E-Mail Removed).. .
>> Stuck pixel. If still under warranty send it in to have it mapped out.
>> Maybe someone else can point to a user utility to do such as is
>> available for some other makes/models.

>
>Any idea why it would only show up on night shots?
>

It's probably there on all your shots, it's just that a longer
exposure time makes it more prominent.

To check, set camera to full manual, man.focus and 30 second exposure.
Shoot in RAW format. Leave the lens cap on and take a picture. The red
dot should be there.

--
HooDooWitch (NaCl - Gratis)

http://www.usefilm.com/photographer/51251.html
 
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Joshua Beall
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Posts: n/a
 
      07-06-2004
"marlin" <(E-Mail Removed)> wrote in message
news:l_zGc.27254$(E-Mail Removed)...
> You have a hot pixel. This happens when a CCD is exposed for a long time.
> Some pixels (in your case 1) expose fast, so when you select a slow

shutter
> speed, they show up as red dots. I'm kinda surprised about this in an

E10D.
> How old is the camera? If it's within 1 year of purchasing (i.e. under
> warranty) you can send it to canon to remap the CCD.


It is less than a year old. I can still get it taken care of under warranty
if need be. I think I will check with some local camera shops to see if
they can get it repaired for me quickly, though, as I would rather not have
to ship my camera off. I would be so lonesome without it...


 
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Mark Spacey
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Posts: n/a
 
      07-06-2004
It is whats called in the trade as a HOT PIXLE, a pixle that registers
hot under long exposores, no cure and they move around ! and usually
appear on all black areas of the picture, just use photoshop to remove
it, they all do it, canon 10 d is no bigger culprit than many other
dslrs, the eos 1ds is a classic for hot pixles, !
 
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Mark Spacey
Guest
Posts: n/a
 
      07-06-2004
It is a hot pixle, they appear on time exposures in black areas, all
canon slr do it, the eos 1ds is worst of all, it happens when a sensor
becomes confused and registers hot, very easy to remove from images ,
use the red eye tool in photoshop or similar,
Not worth worrying about
>

 
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Journalist-North
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Posts: n/a
 
      07-06-2004

"Joshua Beall" <(E-Mail Removed)> wrote in message
news:CnzGc.24984$(E-Mail Removed)...
>
> Here is a crop of an image that shows the dot:
> http://joshbeall.com/personal/redDot.jpg (41k)
>
> Here is the original shot. The dot is at (2093,1472):
> http://joshbeall.com/personal/moon.jpg (1.1m)
>
> Thoughts?
>
> Sincerely,
> Josh

--------------

Seems to be a reflection off something... [LOL]

Journalist
>


 
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Ryan Robbins
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Posts: n/a
 
      07-15-2004

"Joshua Beall" <(E-Mail Removed)> wrote in message
news:CnzGc.24984$(E-Mail Removed)...
> Hi everyone,
>
> I have noticed a small red dot on pretty much all the night pictures I

have
> shot. It happens with both my 28-80 and my 75-300 lenses, so I do not

think
> it is a lense problem. Also, I do not notice this shot except during

night
> or dark shooting conditions. Even indoor lighting with no flash does not
> reveal this dot.


It appears to be a hot pixel, which is common on long exposures or at high
ISO settings.


 
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