Strange artifacts with Nikon CoolPix 2200

Two years ago I got some strange artifacts when I shot a couple of shots
when I was at the antiparos island:

On the first image it is most obvious as a circular feature above the
chairs:
http://misc.virtualcomposer2000.com/artifacts1.jpg

On the second image, there are around a dozen of them, but they don't show
too well. They can still be seen looking at the jpg at an angle:
http://misc.virtualcomposer2000.com/artifacts2.jpg

On the third image there are again around a dozen, this time better seen
against the wall and against the dark space:
http://misc.virtualcomposer2000.com/artifacts3.jpg

On the next one, a big one can be seen on the boundary between lower wall
and dark space, left of the chairs:
http://misc.virtualcomposer2000.com/artifacts4.jpg

Here's the daytime background, used as a reference, which shows that there's
nothing behind the dark space:
http://misc.virtualcomposer2000.com/background.jpg

To preclude the possibility that these were location dependent, I shot one
shot against the dark sky, where two of them are still visible:
http://misc.virtualcomposer2000.com/artifacts5.jpg

I extracted the most evident artifact from the first shot and processed it
with Photoshop, adjusting contrast and luminosity. Here's what it looks like
processed:
http://misc.virtualcomposer2000.com/artifact.jpg

I was at the time in a joking mood, so I showed them to my x, who
immediately freaked out :-))

If you also look at Stephen's mugshot, at Martin's s.a.a. mugshots page:
http://www.theastropost.com/S.A.A.%20MUGSHOTS.html

you'll undoubtedly notice two similar circular artifacts: One above his head
and one left of his right hand.

The artifacts on my photos seem to move, even though the shot location above
is fixed. I have been taking scientific photos for at least 20 years, but
have never seen such artifacts with regular film cameras. So the phenomenon
seems confined to digital cameras.

During the subsequent days, no matter how hard I tried, I could not
photograph any more of these, so these were present only on specific times,
indicated by the photo dates.

Does anyone have an exact scientific explanation for this sort of thing? In
particular, what exactly causes such a rich internal structure on the
circular artifact as seen on the last photo? It looks to me like the
flashlight is being refracted against something, but I have no idea what.

Thanks much,
--
Ioannis

"John Steinberg" wrote in message
...

Hey John,

I thought I was in your killfile!

Ioannis wrote:

On the first image it is most obvious as a circular feature above the
chairs:
http://misc.virtualcomposer2000.com/artifacts1.jpg

The infamous Nikon dandelion internal reflection problem. It's been
previously documented. What's new in that image is the auto selective
focus. See woman to the left of reflection.

This woman is no longer with me, so there was no reason to show her
publically, so I applied a Gaussian blur to her face.

[snip]

What breed of dog is that and what's up with his paws?

That's an Bobtail Sheepdog. It has the strange property of always looking 3
times larger than what it actually is:

http://images.google.com/images?svnu...btail+sheepdog

[snip]

Seriously, I've seen these kinds of artifacts in many of my own Nikon
digital cam shots. It's my belief -- untested and unsupported by
empirical documented evidence -- that they are internal reflections
attributable to the camera lens and stray reflections from external
lighting sources.

Well, if these artifacts were internal reflections, it seems to me that they
would be reproducible. No matter ho hard I tried, I could not get any new
ones the next day, same hour, same position, same photo settings.

Also, the lens of the Nikon Coolpix, is completely shielded when the camera
is off, so dirt on the lens doesn't seem to cut it either. The camera was
brand new when I took these shots.

What's causing this, appears to be an object located between camera and
scene, i.e., probably half way between the flash and the scene's main
objects. At least as much as I gather. So far, I haven't seen any viable
explanations. Do you remember where you have seen it documented?

Thanks,

Just a wag (wild ... guess)
--
-John Steinberg
--
Ioannis

Ioannis wrote:
Two years ago I got some strange artifacts when I shot a couple of shots
when I was at the antiparos island:

On the first image it is most obvious as a circular feature above the
chairs:
http://misc.virtualcomposer2000.com/artifacts1.jpg

On the second image, there are around a dozen of them, but they don't show
too well. They can still be seen looking at the jpg at an angle:
http://misc.virtualcomposer2000.com/artifacts2.jpg

On the third image there are again around a dozen, this time better seen
against the wall and against the dark space:
http://misc.virtualcomposer2000.com/artifacts3.jpg

I'm not sure if you are joking or genuinely want to know the cause.

Typically you get this problem on night time flash photographs where
there is dust and/or small flying insects in the air. At full aperture
and maximum flash power the reflection off anything close to the camera
shows very strange out of focus effects from Fresnel diffraction
patterns. You can get the same sort of visual effect by holding your
eye close to a rainy window and looking at a distant street light.

I have a whole host of similar ones taken at a shin-dig where the
dancers were disturbing dust from the rafters. It wasn't obvious at the
time, but the images were rendered mostly unusable by circular dust
blats across the dancers faces.

Snow flakes are usually big enough to be obvious and atmospheric - but
close in dust with the flash on full whack are really damaging if they
line up with something you care about.

Regards,
Martin Brown

"Martin Brown" wrote in message
oups.com...


Ioannis wrote:
Two years ago I got some strange artifacts when I shot a couple of shots
when I was at the antiparos island:

On the first image it is most obvious as a circular feature above the
chairs:
http://misc.virtualcomposer2000.com/artifacts1.jpg

On the second image, there are around a dozen of them, but they don't
show
too well. They can still be seen looking at the jpg at an angle:
http://misc.virtualcomposer2000.com/artifacts2.jpg

On the third image there are again around a dozen, this time better seen
against the wall and against the dark space:
http://misc.virtualcomposer2000.com/artifacts3.jpg

I'm not sure if you are joking or genuinely want to know the cause.

No, I am not joking. It was one of those rare times when I was caught
scientifically unawares. My x gf freaked out, thinking those were some sort
of divine apparition, and I (who had the reputation of being "Mr.
Knowitall"), failed miserably to quiet her down with a consistent scientific
explanation. Thus the quandry.

Typically you get this problem on night time flash photographs where
there is dust and/or small flying insects in the air. At full aperture
and maximum flash power the reflection off anything close to the camera
shows very strange out of focus effects from Fresnel diffraction
patterns. You can get the same sort of visual effect by holding your
eye close to a rainy window and looking at a distant street light.

Ok, I think that makes sense. The only thing that I recall from this
particular night when I took these shots, was that it was very windy during
the day, with strong northern breezes, which cleared the nighttime sky to
6.5+ skies.

Apparently the wind carried dust particles off the fields nearby and the air
was still saturated with them, at the time the shots were taken. This would
also explain the variable spot locations between the shots, because of
air/dust particle movement.

I have a whole host of similar ones taken at a shin-dig where the
dancers were disturbing dust from the rafters. It wasn't obvious at the
time, but the images were rendered mostly unusable by circular dust
blats across the dancers faces.

Snow flakes are usually big enough to be obvious and atmospheric - but
close in dust with the flash on full whack are really damaging if they
line up with something you care about.

Thanks much,

Regards,
Martin Brown
--
Ioannis

"John Steinberg" wrote in message
...
[snip]
That's an Bobtail Sheepdog. It has the strange property of always
looking 3
times larger than what it actually is:

http://images.google.com/images?svnu...btail+sheepdog

It's huge, at least to me. In January of this year I had to put our
18-year-old cat down. He was less than 5lbs. at that time. I suspect
that dog *eats* close to 5lbs. a day. [Note: For the greater good I
opted not to go with a reference to Jack Palance's line about Billy
Crystal.] Great looking pooch in any event.

I am surprized you didn't recognise the race. For the terminally qurious,
the bobtail sheepdog has been featured numerous times on Warner Brothers'
Coyote series. It's the same Coyote as the one with Meep-meep, but
occasionally wonders into sheep herds, where there is a quiet huge dog, with
eyes covered by hair, who guards the sheep. The Coyote tries all sorts of
tricks, but the sheepdog, although almost entirely blinded by its facial
hair, always anticipates the Coyote's moves. At the end of the day, the
daytime sheepdog stands up, picks up its suitcase, hits its punched card and
leaves, always greeting the next guardian sheepdog who comes in walking, by
"Hi George...", "Bye George..." :-)

[snip]

Clearly, objects like dust, gnats, flying goats, and other air born
objects could also be implicated. It doesn't take but a tiny speck of
something out of focus in the foreground to leave a big fingerprint on
the background.

Yes. See also Martin's reply.

--
-John Steinberg
--
Ioannis

"Ioannis" wrote in news:1153418883.305568@athnrd02:

Two years ago I got some strange artifacts when I shot a couple of shots
when I was at the antiparos island:
Snipola

Dust illuminated by the flash, close to the camera, thus out
of focus.

Or....it's spiritual orbs, often seen in photographs of
haunted houses and cemetaries. Or at least that's what
they say on C2C.

Brian
--
http://www.skywise711.com - Lasers, Seismology, Astronomy, Skepticism
Seismic FAQ: http://www.skywise711.com/SeismicFAQ/SeismicFAQ.html
Quake "predictions": http://www.skywise711.com/quakes/EQDB/index.html
Sed quis custodiet ipsos Custodes?

On 20 Jul 2006 13:50:52 -0700, "Martin Brown"
wrote:

Typically you get this problem on night time flash photographs where
there is dust and/or small flying insects in the air...

The scary thing is that there are whole websites devoted to these sorts
of images, complete with long discussions about whether these are
aliens, angels, or something else. (And, of course, yet more sites
devoted to "rods", which have a similar cause but are usually daytime
artifacts.)

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

(And, of course, yet more sites
devoted to "rods", which have a similar cause but are usually daytime
artifacts.)


Chris, what are rods?

-Florian

On Fri, 21 Jul 2006 01:38:28 GMT, Florian
wrote:

Chris, what are rods?

Little rods or strands that sometimes show up on outdoor images,
especially those taken into the Sun. If you are rational, they are out
of focus insects, otherwise, they are little alien lifeforms that live
amongst us, or maybe spirits. Probably related to chemtrails g.

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

Florian wrote:
(And, of course, yet more sites
devoted to "rods", which have a similar cause but are usually daytime
artifacts.)


Chris, what are rods?

-Florian



Google turned up this, among others...

http://www.amsky.com/ufos/rods/