Steve'sDigicams

Bloodstrike · Feb 23, 2004, 6:09 PM

My Powershot A40 also had spots, but I think it was the lens. Because when I cleaned the lens I didn't saw the spots in my pictures anymore. This picture I took in Bali.

pedro nuno · Mar 17, 2004, 5:59 PM

The problem we are discussing here is rather well described with photos above , I think you can forget lens problems , and it also those not seem “noise” to me. I have got many photos in many different conditions with it , they have got only one thing in common : the using of flash , so the cold air explanation is also improbable for me. Any way it does not worries me a very much , let me tell you that, one night i made 90 flahs photos with a nikon 5700 (that is a great digi-cam ) and 7 of them had those spots , so it seems that is a universal problem of digital photo, and probably few people knows the true reasons for it.

Here goes another sample token by “Nikon 5700”

Regards

CowboySlim · Mar 17, 2004, 9:39 PM

Slim
Who knows a UFO when he sees one.

Oleg · Mar 19, 2004, 3:37 AM

I showed this pic to a friend and he suggested it might be a diffraction pattern. Usually you don't get such a structured picture because most of dust we deal with is of soft kind - fibres, fluffs, etc., which give smooth spots. If by chance you run into hard dust particles with flat sides, they work as a point light source, and the light wave properties might become essential. Not sure if it's true - it would be interesting to experiment with different kinds of dust. I'm surprised there so many guesses about that, and so few professional reviews.

jrobert · Mar 26, 2004, 12:30 PM

It seems to be a feature of built-in flashes on small cameras that these spots appear in flash pictures. It's due to the flash being nearly on-axis, so reflections off off dust particles come directly back the lens. Larger cameras usually have the flash further from the lens axis so the dust is illuminated more from the side.

-jeff-

Oleg · Mar 30, 2004, 2:04 AM

Yes, most likely it's dust reflecting the flash beam. The question was about the spots' structure. Here is the link again (click the pics to enlarge them):

http://hommie.narod.ru/spots.htm

If you take a closer look at pedro nuno's pic, you'll see it too - a sort of kernel surrounded by circles. The question was what is this structure?

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Feb 23, 2004, 6:09 PM	#11
Bloodstrike Member Join Date: Jan 2004 Posts: 62	My Powershot A40 also had spots, but I think it was the lens. Because when I cleaned the lens I didn't saw the spots in my pictures anymore. This picture I took in Bali.

Mar 17, 2004, 5:59 PM	#12
pedro nuno Junior Member Join Date: Feb 2004 Posts: 14	The problem we are discussing here is rather well described with photos above , I think you can forget lens problems , and it also those not seem “noise” to me. I have got many photos in many different conditions with it , they have got only one thing in common : the using of flash , so the cold air explanation is also improbable for me. Any way it does not worries me a very much , let me tell you that, one night i made 90 flahs photos with a nikon 5700 (that is a great digi-cam ) and 7 of them had those spots , so it seems that is a universal problem of digital photo, and probably few people knows the true reasons for it. Here goes another sample token by “Nikon 5700” Regards

Mar 17, 2004, 9:39 PM	#13
CowboySlim Junior Member Join Date: Mar 2004 Posts: 15	Slim Who knows a UFO when he sees one.

Mar 19, 2004, 3:37 AM	#14
Oleg Member Join Date: Oct 2003 Posts: 98	I showed this pic to a friend and he suggested it might be a diffraction pattern. Usually you don't get such a structured picture because most of dust we deal with is of soft kind - fibres, fluffs, etc., which give smooth spots. If by chance you run into hard dust particles with flat sides, they work as a point light source, and the light wave properties might become essential. Not sure if it's true - it would be interesting to experiment with different kinds of dust. I'm surprised there so many guesses about that, and so few professional reviews.

Mar 26, 2004, 12:30 PM	#15
jrobert Junior Member Join Date: Feb 2004 Posts: 11	It seems to be a feature of built-in flashes on small cameras that these spots appear in flash pictures. It's due to the flash being nearly on-axis, so reflections off off dust particles come directly back the lens. Larger cameras usually have the flash further from the lens axis so the dust is illuminated more from the side. -jeff-

Mar 30, 2004, 2:04 AM	#16
Oleg Member Join Date: Oct 2003 Posts: 98	Yes, most likely it's dust reflecting the flash beam. The question was about the spots' structure. Here is the link again (click the pics to enlarge them): http://hommie.narod.ru/spots.htm If you take a closer look at pedro nuno's pic, you'll see it too - a sort of kernel surrounded by circles. The question was what is this structure?