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DPChallenge Forums >> Hardware and Software >> Unusual white specks
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Showing posts 1 - 25 of 27, (reverse)
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 07/25/2005 03:24:57 AM · #1
I'm seeing strange white specks on the pictures I take after about my 530th image... all in the same exact spot... does anyone know what they could be from? how would you get rid of them? they're about 5-10 or so pixels in diameter...
 07/25/2005 03:27:56 AM · #2
Can you show us an example? A full-sized crop of the affected area would be best.

David
 07/25/2005 03:33:26 AM · #3
sure kinda like that... although they change in color slightly, every now and again.... and one of those disappeared... at least I can't find it anymore.... but that's what they look like
 07/25/2005 03:40:53 AM · #4
Is it showing up on all photos? Try a differen tlens and see if they show. That will help narrow it down to lens or sensor needs cleaned.
 07/25/2005 03:44:27 AM · #5
Regretably, I don't own a second lens at this time...... I'll probably go to the local photo place... might try a seperate lens there...

And yep, it's showing up on all the pictures after a certain one....
 07/25/2005 03:45:35 AM · #6
Sensor or mirror dust.
 07/25/2005 04:29:45 AM · #7
Originally posted by faidoi:
Sensor or mirror dust.


Sensor dust typically shows up as dark spots, and mirror dust has no effect on the captured image, just the viewfinder..

This could be a couple of 'hot pixels'..

sukuriant, what settings is this photo taken under? ie: iso & shutter speed..

Cheers, Me.
 07/25/2005 04:40:32 AM · #8
the collection of pictures that have the dots have been under varying ISO speeds, apertures, and shutters... that particular image is...

ISO400
shutter: 15 seconds (it was a night-ish picture)
aperture: f/9

And for a random check, I dropped the ISO to 100 and the spots are more defined... more circular, etc

Message edited by author 2005-07-25 04:47:03.
 07/25/2005 04:47:55 AM · #9
Originally posted by KiwiChris:

This could be a couple of 'hot pixels'..


Doesn't sound like it if they are "about 5-10 or so pixels in diameter". sukuriant is the photo you posted a 1 to 1 crop?
 07/25/2005 04:49:21 AM · #10
I had a similiar problem once a while back and found it to be the CF card. It only occured after a certain number of images on the CF card - then every one after that had the spots. I switched cards and never had the problem again. Have you tried a different card?
 07/25/2005 04:57:42 AM · #11
where the dots in the same, exact location? and did they change purity with different ISOs?
 07/25/2005 05:41:01 AM · #12
they were always in the saem spot - but I can't remember whether or not they changed opacity with different ISO speeds or not
 07/25/2005 06:09:59 AM · #13
Interesting.. If you're shooting raw it's possible that a CF card error would show up in the same place in some images all the time. With JPEG I would expect it to be a little random, as the file sizes are different the data would be written to a different spot on the card.


07/25/2005 12:47:44 PM · #14
Originally posted by tomlewis1980:
Originally posted by KiwiChris:

This could be a couple of 'hot pixels'..


Doesn't sound like it if they are "about 5-10 or so pixels in diameter". sukuriant is the photo you posted a 1 to 1 crop?


Yes, it's a 1->1 crop (assuming 1->1 means a crop with no resize)

The files are JPEGs... They're a little easier to slideshow than RAWs and I've not done anything for the contests yet, so *shrugs*

Also, something interesting, when I have the lens cap on, the dots still appear, in the same location still

Message edited by author 2005-07-25 12:49:36.
 07/25/2005 12:51:45 PM · #15
ya i think every camera has a few hot pixels, it's normal
 07/25/2005 12:53:03 PM · #16
That the spots show up in the same location with the lens cap on is no surprise at all, since they are in some way integral to the system. It doesn't sound like they can be artifacts of the CF card if they are that consistent. Otherwise Ihave no clue, they seem too big to be hot pixels but I am just guessing anyway...

I'll leave it to the tech geeks.

Robt.
 07/25/2005 12:59:43 PM · #17
I had the same problem - i thought they were hot pixels, but my bro said they were to big to be hot pixels. I cleaned the sensor - and they seemed to be gone, so i would suggest trying that.

Message edited by author 2005-07-25 12:59:56.
 07/25/2005 02:06:56 PM · #18


Here are a few examples of what I believe to be hot pixels on my 10D, hope this helps in way of comparison.
These were copied from a photo taken with the lens cap on and the following settings: 30 sec, ISO 100, F32.
 07/25/2005 02:13:03 PM · #19
Originally posted by tomlewis1980:
...These were copied from a photo taken with the lens cap on and the following settings: 30 sec, ISO 100, F32.


Have you tried this to see what you get? This may help.
 07/25/2005 02:17:04 PM · #20
Originally posted by sabphoto:
Originally posted by tomlewis1980:
...These were copied from a photo taken with the lens cap on and the following settings: 30 sec, ISO 100, F32.

Have you tried this to see what you get? This may help.

Eh?
 07/25/2005 02:17:50 PM · #21
Originally posted by tomlewis1980:


Here are a few examples of what I believe to be hot pixels on my 10D, hope this helps in way of comparison.
These were copied from a photo taken with the lens cap on and the following settings: 30 sec, ISO 100, F32.


Weird how it is in a pattern like that. I sure wish canon had the re-mapping function available without having to send the camera in.
 07/25/2005 02:20:17 PM · #22
Originally posted by louddog:
Weird how it is in a pattern like that. I sure wish canon had the re-mapping function available without having to send the camera in.


Not so weird actually I cut and pasted them from across a full image, sorry I should have made that clear :-)
 07/25/2005 04:43:37 PM · #23
Originally posted by louddog:
Originally posted by tomlewis1980:


Here are a few examples of what I believe to be hot pixels on my 10D, hope this helps in way of comparison.
These were copied from a photo taken with the lens cap on and the following settings: 30 sec, ISO 100, F32.


I just did this and counted, I think, 7 'hot pixels' of varying colors, white, blue, etc....... If I had it sent to Canon (year warranty) can they get rid of them? or?
Weird how it is in a pattern like that. I sure wish canon had the re-mapping function available without having to send the camera in.

Message edited by author 2005-07-25 16:44:28.
 07/25/2005 04:43:46 PM · #24
clean your sensor first. If it's still there then cosider hot pixels and the less common stuff.
 07/25/2005 04:45:51 PM · #25
Originally posted by yido:
clean your sensor first. If it's still there then cosider hot pixels and the less common stuff.


I'm a bit worried about cleaning my sensor... a took it to a place I trust (not Circuit City, a local photo shop), and they said they were afraid to do it, as it might hurt it more... if it had been a larger spot, they would have done it...
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