Strange streak discussion: 2004 Dec 7 APOD

[mike the plumber]

Is it possible to be an "Orion" signal flare from a 12 guage signal gun? They will gain an altitude of 250 feet, glow with 15,000 candle power and come in white and red. There are other flares that will gain an altitued of 1000 feet.

[anon]

I think its a bug - with the light shining off its wings... flying past the lense, out of focus, just as the image was taken.

my $0.02

dave

lol - just saw that fly picture above - yep ... its a bug

dave:P

[twocents]

Usually, when a shadow is seen, such as this could be given a plausable explaination for the source, there is usually some haze, smog, or some other areosol in the air. You need something for the light, and shadow to show up against. Looks like the air is pretty clear as well here, so, I highly doubt it's any kind of shadow.

[Michael Covington]

The gentleman at http://www.dvdc.de/fly/ has done a good job of showing how it might be an insect, caught in the camera's flash and then leaving a dark streak during the rest of the exposure. Notice that unless this is an unusual camera, the flash fired at the beginning of the exposure. The EXIF data indicates that the flash did fire.

I'm also curious about CCD artifacts. Given a very overexposed spot - from the light bulb burning out explosively or from an object on the water reflecting the sun - does anybody know how a diagonal streak might result? I've seen CCD blooming, but it's always vertical or horizontal.

The image was JPEG-compressed, and that's another source of artifacts.

What we really need is for someone to use the same type of Canon camera to photograph a really overexposed spot against a medium-gray uniform background, and see what artifacts we get.

Michael Covington
Author, Astrophotography for the Amateur
http://www.covingtoninnovations.com/astro
(no, there is nothing on that site pertaining to this question)

[jeisberg]

We're told the light wasn't working after the strange streak. Do we know whether the light was working before?

[tomgoes]

It's a bottle rocket caught in the act of flight and explosion near the Lamp post, doing no damage but raising some confusion

[twocents]

Despite the photoshop filtering someone above did, I don't know too many flies that leave a dark trail behind them or manage to darken (dodge) the image along it's path, , travel fast enough to half-traverse the frame, show up glowing (ok, maybe flash was used), and, travel in a perfectly straight line, even of only a couple inches.

Image artifact.

[Guest]

It's one of the rarest types of lightning out there!

[bmcdonald]

Can anyone comfirm that a flash was used? Many comments refer to the camera's flash, but it doesn't make any sense to me to use a flash for timelaps photography of clouds.

[Jim]

Im inclined to agree wth several of the others that say that the flash was generated by the light bulb blowing while the line is a shadow.

This is based on the following logic: 1) the light is not working, 2) there was no apparent external damage to the pole or housing, 3) meteor experts say it's not a meteor, and 4) lighting experts say its not lightning. The contrail idea is interesting, but do contrails flash?

[lstrauss]

okay, it's a bug caught by the flash and revealed in Photoshop. Now we do still have to explain how did the bug leave a track?
(would new posters please read the thread before asking questions that have been answered..)

[Guest]

What that looks like to me is a engine trail from a dirty prop aircraft (something like a C-130-K) and the light, well it is roughly the right height for the top of a lampost. So my guess is this.

The Light is exacty that, a light that is flickering and just starting to turn it's self on, and the trail is the wash from a dirty prop driven aircraft.

[jorgen@qedata.se]

It is probably a shadow of a contrail, because when I did even more analysing in Photoshop, the straight "shadow" does not extend into the forest line and bright sea.

[Dave C]

Sometimes a jet contrail lines up with the sun. The shadow of the contrail looks like a dark streak. You can't the shadow of most contrails because the shadow forms a plane (one of those flat things from math, not an airplane) and you need to be located in that plane to see it. When you see a contrail cross the sun, you can often see a dark shadow on the sky like this one.
I don't know what the flash is. Maybe a reflection or an electric light. It is pure coincidence that the flash is located at one end of the contrail shadow.
Regards,
Dave C.

[decoder]

Despite the photoshop filtering someone above did, I don't know too many flies that leave a dark trail behind them or manage to darken (dodge) the image along it's path, , travel fast enough to half-traverse the frame, show up glowing (ok, maybe flash was used), and, travel in a perfectly straight line, even of only a couple inches.

Image artifact.

I'm not a professional photographer.

I have assumed that the trail is the result of the exposure...

The environment light was poor (see clouds) and flys are usual dark in a low light. The camera was most likelly in the Auto mode therefore the exposure time was low so that the picture gets more light.

Later the flash was activated and picture was taken.

The glow is maybe from a reflection on the fly wings and/or the abdomen.

The "smoke" around the glow are the wings. It is somehow perpendicular on the trajectory.

[gerald davis]

I have seen this only once that I can remember and to me it looked like and invershion of two different cloud or temperture layers. It is not ball lighining as I have seen this frist hand and dont want to see it again.

[Gnea]

Alright, the photographer says this picture was taken today, Tuesday December 7, 2004, but is the time on this forum 2 days in the past? Would the server admin please fix this?

Well, back to the original photo, what TIME was it taken at? It looks like it might've been taken around noontime, but only the date itself is given. Difficult to perform a proper analysis without the actual timeframe.

[alientro]

I havnt read all 23 pages of posts yet but if it hasnt been said. This is a picture of someone shooting a gun at the light. the gun being off to the left and above the camera.

[Guest]

I'm for the very small meteor theory. It appears that it doesn't strike the light pole but instead travels behind it. The "shadow" is the vapor/smoke trail, the "flash" is the meteor itself and the white "smoke" is the pressure wave of the meteor. The next picture isn't taken until 15 seconds later which would be enough time for the trail to dissipate.

[Bob]

We must know if the original is film or digital. If its film, can you verify there is no damage to the negative? The next possibility to consider is a flaw in processing, something on the surface of the film interfering with the chemical development process. If the dark streak were a shadow, it must be cast on something. Is it cast on haze? Why don’t we see more illuminated haze “around” the shadow? The only thing in this photo with direct sunlight hitting it is a cloud in the distance. If the dark streak were a shadow it would probably have to be cast by the light reflected off the cloud. If the cloud were the source of light creating the shadow on haze effect, we would be able to see what was casting the shadow too. The object casting the “shadow” cannot be too far away because the “shadow” is so narrow and the light reflecting off the cloud is diffused. The reason the “explosion” appears to be in the foreground is because there is no reflection of it on the water in the background. If it were an explosion, its reflection would be on land and you could argue there is too much clutter to see its reflection. If the dark streak is not a flaw on the negative/slide and is not a shadow on haze, it could be particles in the atmosphere. What would leave a trail of particles like this?

[Guest]

Consider that the occurance of a contrail and the burst of light are actually two separate occurances. It may actually be coincidental that the two Phenomena allign.

[Apollo]

I've inversed it, blown it up, and when you blow it up to 500 times it reveals more clearly what could be a cloud of smoke around the lamp post. seemingly eminating from the bottom but more consistant with an explosion given the amount of the substance around where the bulb should be located and thinning as it "shoots or trails out" from the source .something definitely is there dust or smoke my guess would be smoke, this is not to say it has anything to do with the "line"- perhaps this "line" some one shooting off a bottle rocket ( this might explain the "smoke") or even a hair passing through the frame at the same time the lamp went , if it went at all.

[Guest]

1) This can not be a bug. That is just silly. Get a copy of the full picture and look at how small this "bug" would need to be. It would have to be VERY close to the lens to make the trail that long in 1/20th of a second and would have to be impossibly small to create the thin shadow line and the pinpoint flash on the picture. A gnat going Mach 10 couldn't do this.

Let's see, a bug going 1 m/s would cover 5 cm in 1/20 s. To cover that much distance in the picture, let's say it would have to be 10 cm in front of the lens. And it might have been very small. The wind blew from the right and behind I think, so it could easily have been carried on the wind. No need for the gnat to be going supersonic.

The particular photographic effect in question is very easy to duplicate. In fact, people purposefully create similar [url=http://brandon_liew.tripod.com/Gallery/various_light_painting.jpg]effects[/url] all the time. The concept is simple: you open the shutter for a longer exposure and shoot the flash at the end (or beginning) of the shot to freeze objects in motion with the flash. You can do pretty cool things with this:



Now in this case, the resulting image was different, but the cause was probably the same. Looking at the image data, we can tell two important things: The exposure was relatively long, and the flash was fired. Who knows why they were using a flash for this particular shot, but it doesn't matter.

So the camera shoots its shot and a bug flies by. For 1/20th of a sec, the bug shows up as a dim blur along its path. Then, the flash fires, and the bug is lit up -- but because it is so close, you only see a highly blurred ghost of the parts of the bug that were reflecting light back to the camera.

As for the straightness of the path, it doesn't even matter where the wind was. I would imagine that anybody tracing the path of a fast moving bug for merely 1/20 sec. would think it relatively straight. The line has a variable darkness and thickness, anyway -- who's to say that it is even perfectly straight?

I tested this out with my digital camera, swinging a pendulum around at close range. I couldn't duplicate the exact camera settings of that image because my camera doesn't allow precise exposure control, but even at 1/500 sec. exposures, the pendulum would leave a dark trail leading up to a light flare where the flash froze the pendulum in place. It's very believable that the same could happen in 1/20 sec., a much longer exposure.

A lot of people have made comments inferring that since the line didn't go through the water, this meant that this was a sky phenomenon. But this kind of blur-exposure effect is sensitive to whatever the moving object is blurring over. This is especially true with digital cameras that have different sensitivities to different light levels.

As a note, this wouldn't be the first time that an automated camera caught a bug.

[Guest]

This discussion reminds me of some Mars Face explanations I've seen.

My vote is for a contrail shadow and coincidental unrelated flash from the lamp.

[thecloth]

Unless there's human collaboration I'd dismiss it as digital abberation