Approve the Cookies
This website uses cookies to improve your user experience. By using this site, you agree to our use of cookies and our Privacy Policy.
OK
Index  •   • New posts  •   • RTAT  •   • 'Best of'  •   • Gallery  •   • Gear  •   • Reviews
Guest
New posts  •   • RTAT  •   • 'Best of'  •   • Gallery  •   • Gear  •   • Reviews
Register to forums    Log in

 
FORUMS Post Processing, Marketing & Presenting Photos RAW, Post Processing & Printing 
Thread started 19 May 2012 (Saturday) 16:45
Search threadPrev/next
sponsored links
(this ad will go away when you log in as a registered member)

what is the white dot that appears on some images?

 
picard
Goldmember
Avatar
1,996 posts
Likes: 1
Joined Jan 2006
Location: Canada
     
May 19, 2012 16:45 |  #1

what is the white dot that appears on some images?

The white dot looks like a burn out pixel


Canon 1DM4,7D, Rebel XT
580 EX II, 430 EX II
Canon 70-200mm IS II L , Canon 85mm F1.2 L II, Canon macro 100mm F/2.8, 18-55mm kit
Sigma 18-200mm F/3.5-5.6, Sigma 10-22mm, Sigma 50mm F/1.4
Sigma 24-70mm F/2.8 EX DG HSM

  
  LOG IN TO REPLY
sponsored links
(this ad will go away when you log in as a registered member)
scs
Member
131 posts
Joined Dec 2005
     
May 19, 2012 16:47 |  #2

picard wrote in post #14456130 (external link)
what is the white dot that appears on some images?

The white dot looks like a burn out pixel

it's a hot/stuck pixel, usually masked out with software...




  
  LOG IN TO REPLY
picard
THREAD ­ STARTER
Goldmember
Avatar
1,996 posts
Likes: 1
Joined Jan 2006
Location: Canada
     
May 19, 2012 17:20 |  #3

scs wrote in post #14456135 (external link)
it's a hot/stuck pixel, usually masked out with software...

what is a hot / stuck pixel ?


Canon 1DM4,7D, Rebel XT
580 EX II, 430 EX II
Canon 70-200mm IS II L , Canon 85mm F1.2 L II, Canon macro 100mm F/2.8, 18-55mm kit
Sigma 18-200mm F/3.5-5.6, Sigma 10-22mm, Sigma 50mm F/1.4
Sigma 24-70mm F/2.8 EX DG HSM

  
  LOG IN TO REPLY
tzalman
Fatal attraction.
Avatar
13,482 posts
Likes: 199
Joined Apr 2005
Location: Gesher Haziv, Israel
     
May 19, 2012 17:27 |  #4

It is a pixel that becomes more excited than it should be and churns out many more electrons, thus acting as though it were being hit by a bright light.


Elie / אלי

  
  LOG IN TO REPLY
D ­ Thompson
Goldmember
Avatar
3,870 posts
Likes: 111
Joined Feb 2008
Location: Georgetown, Ky
     
May 19, 2012 21:15 |  #5

picard wrote in post #14456255 (external link)
what is a hot / stuck pixel ?

A white dot. ;)


Dennis
Canon 5D 20D
I have not yet begun to procrastinate!

  
  LOG IN TO REPLY
picard
THREAD ­ STARTER
Goldmember
Avatar
1,996 posts
Likes: 1
Joined Jan 2006
Location: Canada
     
May 19, 2012 21:29 |  #6

tzalman wrote in post #14456276 (external link)
It is a pixel that becomes more excited than it should be and churns out many more electrons, thus acting as though it were being hit by a bright light.

does it mean light overwhelm the sensor in those pixels ? does light problem cause damage to sensor ?


Canon 1DM4,7D, Rebel XT
580 EX II, 430 EX II
Canon 70-200mm IS II L , Canon 85mm F1.2 L II, Canon macro 100mm F/2.8, 18-55mm kit
Sigma 18-200mm F/3.5-5.6, Sigma 10-22mm, Sigma 50mm F/1.4
Sigma 24-70mm F/2.8 EX DG HSM

  
  LOG IN TO REPLY
imjason
Goldmember
1,667 posts
Likes: 3
Joined Nov 2010
Location: Bay Area, CA
     
May 20, 2012 00:07 |  #7

most likely a manufacturing defect. dont worry about it. most cameras have them. if you shoot jpg, usually you will not notice it due to noise reduction and compression. dead, stuck or defective pixels are easily spotted in unprocessed raws. if you use programs such as lightroom, its automatically removed during the de-mosaic process.


Canon gear: EOS M, Canonet QL17, SX230HS, S95, SD1200IS
Non-Canon gear: D600, D5000, D70, XG-2, U20
Flickr (external link)

  
  LOG IN TO REPLY
Skaperen
Member
232 posts
Joined Nov 2009
Location: Wheeling, WV, USA
     
May 20, 2012 00:41 as a reply to  @ imjason's post |  #8

There are various causes for them to exist on sensors, and they can result in values invariant of the light level, or invariant values added to the light level, or even modify the light level itself linearly or non-linearly. Shoot a dark frame (stop down, fast shutter, with lens cap on) and see what you get. In the RAW file, it should still be there. Processing should remove it if it knows or detects which are bad. Cameras record this and know. It can be added to computer post processing. It should get removed from non-RAW files.


7D, 450D, 18-135/3.5-5.6, 18-55/3.5-5.6, 60/2.8 macro
Wish List: 5DsR, 16-35/2.8L,100/2.8L macro, 135/2L, LC-E6E

  
  LOG IN TO REPLY
sponsored links
(this ad will go away when you log in as a registered member)

1,155 views & 0 likes for this thread
what is the white dot that appears on some images?
FORUMS Post Processing, Marketing & Presenting Photos RAW, Post Processing & Printing 
AAA
x 1600
y 1600

Jump to forum...   •  Rules   •  Index   •  New posts   •  RTAT   •  'Best of'   •  Gallery   •  Gear   •  Reviews   •  Member list   •  Polls   •  Image rules   •  Search   •  Password reset

Not a member yet?
Register to forums
Registered members may log in to forums and access all the features: full search, image upload, follow forums, own gear list and ratings, likes, more forums, private messaging, thread follow, notifications, own gallery, all settings, view hosted photos, own reviews, see more and do more... and all is free. Don't be a stranger - register now and start posting!


COOKIES DISCLAIMER: This website uses cookies to improve your user experience. By using this site, you agree to our use of cookies and to our privacy policy.
Privacy policy and cookie usage info.


POWERED BY AMASS forum software 2.1forum software
version 2.1 /
code and design
by Pekka Saarinen ©
for photography-on-the.net

Latest registered member is emmanwarren
907 guests, 238 members online
Simultaneous users record so far is 15144, that happened on Nov 22, 2018

Photography-on-the.net Digital Photography Forums is the website for photographers and all who love great photos, camera and post processing techniques, gear talk, discussion and sharing. Professionals, hobbyists, newbies and those who don't even own a camera -- all are welcome regardless of skill, favourite brand, gear, gender or age. Registering and usage is free.