BuyantUkhaa From Mongolia, joined May 2004, 2781 posts, RR: 3 Posted (7 years 2 months 4 weeks 6 hours ago) and read 2160 times:
Recently I took some pics at night and I realised they all have the same dot (2x2 pixels) that shows up 1009 pixels East and 1485 pixels South of the upper left corner of the pic (when in landscape), or at the bottom of the pic slightly left of the middle. I use an Olympus C765UZ.
Let me show what I mean:
http://dacabeca.com.sapo.pt/KGDhotel.JPG
This pic is blurred and that's why I chose it: the dot is sharp and not blurred, unlike everything else on the pic. The dot is on the pavement, below the right end of the wall. You'll need to zoom to at least 100% to see it.
DC10Tim From United Kingdom, joined Jan 2005, 1405 posts, RR: 16 Reply 1, posted (7 years 2 months 4 weeks 6 hours ago) and read 2148 times:
It looks almost like a dead pixel on the sensor. There is another about 1/4 of the way across and about half way up on all 3 too, though it is not noticable. I haven't seen that before unfortunately, so have no idea how to go about getting rid of it. When editing photos though, you could simply clone it out and no-one would ever know it has been there.
BuyantUkhaa From Mongolia, joined May 2004, 2781 posts, RR: 3 Reply 2, posted (7 years 2 months 4 weeks 6 hours ago) and read 2129 times:
You're right about the other, I hadn't seen that before. Yes I can edit out this pixel, but it obviously wouldn't be very convenient... The only upside of it is that pics taken in daylight do not seem to suffer as much from this dead pixel...
JeffM From United States of America, joined May 2005, 3266 posts, RR: 53 Reply 3, posted (7 years 2 months 4 weeks 6 hours ago) and read 2129 times:
Quoting DC10Tim (Reply 1): I haven't seen that before unfortunately, so have no idea how to go about getting rid of it.
You can't. Those pixels are stuck "on". It's not uncommon, I had on on my D100 after a week. Took it back. Have not had one show up on my Canon, but they are almost inevitable.
BuyantUkhaa From Mongolia, joined May 2004, 2781 posts, RR: 3 Reply 7, posted (7 years 2 months 3 weeks 6 days 14 hours ago) and read 2024 times:
Quoting Mikephotos (Reply 5): For other wanting to test their cameras for dead/hot-pixels, here's a good link:
Thanks for the program! I just did some test shots:
So now I know they're not dead pixels, bot hot pixels, so they should mean trouble only at night or other strange circumstances. They're clustered in blocks.
TIFF JPG
ISO 64 28(8) 33(10)
ISO100 12(3) 12(3)
ISO200 12(3) 12(3)
ISO400 10(3) 10(3) Number of pixels (number of distinct areas)
The strange thing is that at ISO400, several pics give different results, even though the settings are identical. The number varies from 28 to 45 in TIFF and from 9 to 10 in JPEG.
Tonimr From Spain, joined Jan 2001, 325 posts, RR: 25 Reply 8, posted (7 years 2 months 3 weeks 6 days 10 hours ago) and read 1992 times:
Quoting JeffM (Reply 3): You can't. Those pixels are stuck "on". It's not uncommon, I had on on my D100 after a week. Took it back. Have not had one show up on my Canon, but they are almost inevitable.
There's an utility to remove them, at least on the D100. I had one and was succesfully removed following some steps. I could send it to anyone who asks, but at his own risk...
Toni
There is a very fine line between 'hobby' and 'mental illness'.
BuyantUkhaa From Mongolia, joined May 2004, 2781 posts, RR: 3 Reply 9, posted (7 years 2 months 3 weeks 6 days 10 hours ago) and read 1983 times:
Quoting Tonimr (Reply 8): There's an utility to remove them, at least on the D100. I had one and was succesfully removed following some steps. I could send it to anyone who asks, but at his own risk...
Interesting! How does that work? Is it software or hardware?
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