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Old Mar 12, 2003, 11:44 PM   #11
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That's exactly what dust in the air look like with internal flash. If your camera's flash was on (check the EXIF) then you have found the culprit. In a dusty environment with flash, it's common to see dozens of these in some images.

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Old Mar 13, 2003, 3:49 AM   #12
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From close examination i noticed a few hot pixels even at 1/32 exposures
Well I'm no expert in 'hot pixels', but if I increase brightness and contrast on the black pic I see clearly defined blocks of pixels with aligned straight edges. Which seems too geometric to resemble a random, single pixel effect. If your lens was capped, this must be produced by processing. Don't think you can shoot uncompressed with this cam to eliminate JPEG. Also try black test with different sharpening settings - do you get the same thing?

Hey, how come on a black test pic your cam flash fires? Can't you turn it off? I mean black should be capped, no extraneous light, light leakage from the internal flash internally, or voltage pickup effects from the flash fire - to make this test mean anything.

Look, all your pics with this problem have flash fired according to the EXIF data. Have you taken a night scene yet with flash turned off? For these type of shots you need to have total control, not let the auto aliens in the cam get their own way!
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Old Mar 13, 2003, 5:35 PM   #13
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hi, I know on that picture it says flash was on and it was. I took 20 pictures with the flash on and off with different expose time of 1/32 to 16 sec. My hot pixels show up in my black pics in all the same location. I know this camera does not do tiff or raw pics just jpg so there will always be more hot pixels. I was close to area 51 last week so who knows? thanks for the comments, i will do some more testing...
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Old Mar 14, 2003, 1:37 PM   #14
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Regarding
http://www.pbase.com/image/14133454

This keeps coming up on many forums...I don't know how to keep users advised all over the Web, but here goes again...


http://home.fujifilm.com/products/di...ing/flash.html
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Old Mar 14, 2003, 1:52 PM   #15
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Originally Posted by MentorRon
Regarding
http://www.pbase.com/image/14133454

This keeps coming up on many forums...I don't know how to keep users advised all over the Web, but here goes again...

http://home.fujifilm.com/products/di...ing/flash.html
To be honest, I've never seen such an artifact caused by dust in any of my pictures...sunspots, yes...and I've been taking pictures for decades. Maybe it's a quirk of cheaper cameras?
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Old Mar 14, 2003, 2:04 PM   #16
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To be honest, I've never seen such an artifact caused by dust in any of my pictures...sunspots, yes...and I've been taking pictures for decades. Maybe it's a quirk of cheaper cameras?
Hi Mike,
It actually is not that uncommon when using a built-in flash with a digital camera in a dusty environment. I assure you it has absolutely "nothing" to do with the "quality" of a camera.

Lin
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Old Mar 14, 2003, 4:07 PM   #17
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Lin...Why is this a problem with digicams? I've never heard of it with small film cams and built in flash. What's so different that causes the problem in a digicam, the resolution isn't so good so I can't understand this unique phenomena. What happens if you shoot pics with flash on a foggy day, or does this become impossible?

I've seen spots caused by light reflection via the lens optics, and have experienced it when just catching the sun, without a shade. I also got something similar once, shooting across water.
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Old Mar 14, 2003, 4:42 PM   #18
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I have seen that with a 35mm point-and-shoot chemical camera that had a built-in flash. It is not common - I think it shows up more with digital simply because people shoot more pictures with digital. Don't know how it shows in fog (ask the Brits about that :-), but it shows with falling snow real seriously.

Do the experiment: do a few shots of a dark/far wall with flash in a dusty cloud. Go outside at night, kick up some dust, and shoot away against the distance. Don't take people's word for it -
do the experiment yourself!!!!
And even when you find out that dust will produce something like that, your problem could still be something else. But I'd sure bet on the flash/dust explaination.
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Old Mar 14, 2003, 6:22 PM   #19
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Quote:
Lin...Why is this a problem with digicams? I've never heard of it with small film cams and built in flash. What's so different that causes the problem in a digicam, the resolution isn't so good so I can't understand this unique phenomena. What happens if you shoot pics with flash on a foggy day, or does this become impossible?
It's really not specific to digita, but had to do with the position of the flash in relation to the lens. It's most common on cameras which also produce frequent red-eye.

Dust being illuminated in out-of-focus areas appears as small globes. To produce the phenomena, the dust must be relatively close to the camera. Most frequently it's seen when shooting at wide angle so that the point of focus is beyond macro limits. It's more common indoors than out, sometimes when there are numerous people in a dusty environment (rodeo, field, etc.) it shows up. I was the photographer for the 10th annual UFO congress in Laughlin, Nevada a few years ago and a crop-circle researcher had this appear in some of his pictures made when a group was doing research in a field in England. They though they were on to some really strange phenomena until I had to demonstrate that I could easily reproduce the effect by simply smacking a hotel pillow and immediately shooting a flash shot wide angle with one of my Nikon (CP990) digicams. I could do the same experiment with my D30 and an external flash and it would never appear. The essence is that the flash on the Nikon is very closely aligned with the lens (thus causing lots of red-eye) and the reflected light from the out-of-focus dust causes the mysterious "orbs" - nothing out-of-this-world in this case, just simple physics.

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Old Mar 14, 2003, 6:43 PM   #20
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Lin..., I'll try and experiment to create the effect as the Fuji602 does easily produce redeye, then I'll try an external flash and change its angle.

I suppose the problem is not always appreciated in daylight on some cams, where the flash is enabled in the menu. Also as digicams get smaller, the flash is getting so close to the lens, you don't need a ring flash! On a 602 you have to release the hinged flash before it will operate. Thanks - VOX
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