IS this Sensor Dust? [Sitemap] - Digital Grin Photography Forum

View Full Version : IS this Sensor Dust?

toadlet

Dec-02-2007, 02:57 AM

I think I have that annoying digital thing called sensor dust. BUT I have not seen the specs that appear in some of my images when I type in searches.

There is the usual 'dust bunny' sensor dust but the 'UFOS' that appear on my images happen at all f stops and a random (sometimes not there other times there) and are noticeable in sky/cloud photos. I thought if it was dust it would only appear say at f8 and above?

I have tried cleaning with a bulb blower and I think this has helped to a degree, but some specs are still there. Could it be maybe bits of metal when changing lenses that dislodge into the chamber?

Anyone else have the kind of stuff I've been seeing?
Cheers

http://thomasryan.smugmug.com/photos/227738685-L.jpg

Skippy

Dec-02-2007, 03:28 AM

I think I have that annoying digital thing called sensor dust. BUT I have not seen the specs that appear in some of my images when I type in searches.

There is the usual 'dust bunny' sensor dust but the 'UFOS' that appear on my images happen at all f stops and a random (sometimes not there other times there) and are noticeable in sky/cloud photos. I thought if it was dust it would only appear say at f8 and above?

I have tried cleaning with a bulb blower and I think this has helped to a degree, but some specs are still there. Could it be maybe bits of metal when changing lenses that dislodge into the chamber?

Anyone else have the kind of stuff I've been seeing?
Cheers

Hi toadlet,
You may need something more than just a blower to clean it with.
If it appears at all FStops as you said, it actually looks like tiny particles rather than dust.

.... Skippy :D
.

Glenn NK

Dec-02-2007, 01:54 PM

If it appears at ALL f/stops, then it's not likely on the sensor. At least that's my view. It also seems to me that spots that well defined would be visible if on the sensor - try looking at it under a bright light (I wouldn't suggest direct sun). I have some small halogen lights in my kitchen under which I've been able to detectd some spots.

I'm not recommending this as general practise, but to check a lens for cleaniness, I breathe gently on the surface - moisture has a knack for collecting on smudges and thereby showing non-visible smudges quite well. I've done this on the sensor too, but left the shutter open for a few minutes to ensure all moisture escaped.

The other (somewhat remote) possibility is in/on the lens. Have you examined the front and rear elements of the lens?

There is a lens that in addition to its reputation for being fast and sharp has "occasionally" sucked in a "bit" of dust. But no one with one of these has actually reported dust in the lens showing up on images.

As you can see, I'm fishing here, but perhaps something on the rear element. I've had some pretty ugly crap on a UV filter that never showed up on the images.

Incidentally, if they are on the sensor, I'd be extremely careful with wet cleaning as anything this well defined could be abrasive. I have had a bad experience - had to replace the sensor filter because I scratched it.:cry :cry

My first step in removing anything like this would be to use a Q-tip that is almost wet with sensor cleaning fluid, and I'd gently touch the spot to see if it loosened - certainly don't drag it across the whole surface (that's what I did).:cry

toadlet

Dec-02-2007, 11:40 PM

Thanks for your advice and replies. The thing is that these spots appear no matter what lens I use (have tried up to 3 different lenses) so I think it would have to be on the sensor. At least these dots seems to move around and are not in all shots, as planning a trip away and would be annoying to have to clean up these marks in images on PP.

If it appears at ALL f/stops, then it's not likely on the sensor. At least that's my view. It also seems to me that spots that well defined would be visible if on the sensor - try looking at it under a bright light (I wouldn't suggest direct sun). I have some small halogen lights in my kitchen under which I've been able to detectd some spots.

I'm not recommending this as general practise, but to check a lens for cleaniness, I breathe gently on the surface - moisture has a knack for collecting on smudges and thereby showing non-visible smudges quite well. I've done this on the sensor too, but left the shutter open for a few minutes to ensure all moisture escaped.

The other (somewhat remote) possibility is in/on the lens. Have you examined the front and rear elements of the lens?

There is a lens that in addition to its reputation for being fast and sharp has "occasionally" sucked in a "bit" of dust. But no one with one of these has actually reported dust in the lens showing up on images.

As you can see, I'm fishing here, but perhaps something on the rear element. I've had some pretty ugly crap on a UV filter that never showed up on the images.

Incidentally, if they are on the sensor, I'd be extremely careful with wet cleaning as anything this well defined could be abrasive. I have had a bad experience - had to replace the sensor filter because I scratched it.:cry :cry

My first step in removing anything like this would be to use a Q-tip that is almost wet with sensor cleaning fluid, and I'd gently touch the spot to see if it loosened - certainly don't drag it across the whole surface (that's what I did).:cry

Glenn NK

Dec-03-2007, 08:53 AM