Strange streak discussion: 2004 Dec 7 APOD

[sleepy]

bulb blowing - yes

streak = shadow cast of part of the pole, blowing light would act as a flash light back towards camera washing out the picture except for the masked off area created by the pole....

something like that....

[Guest]

Did any one notice that there is a very slight blue/green hue in the cloud at the end/origin of the streak. This could be the discharge origin of a lower voltage lightnig discharge

[Guest]

Hi people, dont panic its not something unexplainable, it happens quite often. All it was, was a hair or dust streak on the lens of the camera that took that photo. The wind probably blew it on and off, thats why there is only one photo with that 'streak'
It cant be anything else. Just doesnt make sense. I've heard contrails ? definitively not! for interest, i'll keep on reading this forum.

As my hair is about 3cm long, I doubt the hair theory. Has anyone stop to think that Darwin is one of the northern frontiers and has about 80% military influence. There are a lot of Airforce Joint Country Exercises that happen in the NT, so the sonic boom theory is an everyday part of life (a bit like edwards airforce base!!!) "Why would anyone up here turn around in amazement for a sonic boom, mmm... don't think so!!! either an F-111, FA-18, F-16 Falcon mostly FA-18's is buzzing the sky" and with some of the storms that we have had this year already, a piece of space junk, meteorite, FA-18a fuel pod, would not even raise an eyebrow!!!

[Guest]

do people not realise how crap digital cameras can be with largly contrasting light esp in lower light levels?

the camera has obviously captured the bulb blowing with a flash, causing it to artifact.

[Harry Law]

It can not be a burnt light or fuse. We all know, for a light bulb to burn, it have to be turned on first.

Neither the before or the after picture shows any signs of light being turned on on any of the street light. Geneerally speaking, street lights are usually grouped to be turns on together by one single light senor.

[Joker]

I've seen it before! it's a seagull that was struck by a big-ass lightning bolt in mid-air. That was its burning carcass falling to Earth. They make for good eatin'! Especially since this one's already been cooked. I know where I'm getting my Christmas dinner now!!!

[Rob Crouch]

Here is my "Theory"


Excuse the spelling of flash! Paint has no spellchecker!

I am not a physicist, just thinking as how to explain this amazing picture.

Of course the light from the "Flash" is not channelled or focused just on the lamp fitting per se but is used to illustrate the crude drawing. I did not want to fill the whole picture with yellow.

[Guest]

I live in Central Texas and as I was driving home from work yesterday, Dec. 7th, I saw a black streak across the sky. There was a jet flying the route of the black streak. I have no idea what the streak was or why a jet would have it's course set on it. Just thought it was odd.

[PrydeW]

Here is my "Theory"


Excuse the spelling of flash! Paint has no spellchecker!

I am not a physicist, just thinking as how to explain this amazing picture.

Of course the light from the "Flash" is not channelled or focused just on the lamp fitting per se but is used to illustrate the crude drawing. I did not want to fill the whole picture with yellow.

Sorry Rob,

But from any Omni or Directional light source the shadow would be none other than tapered!!!

Am I wrong here???

[Guest]

According to the exif headers in the parent post, the picture is JPEG, a compressed format. Without the RAW picture to analze it is hard to tell if the "tail" is something that was actually visible or an artifact created by the JPEG creation software inside the camera as it dealt with the bright spot.

It is my best guess that we're seeing the light at the top of the post failing and an artifact created by on-camera processing (to create JPEG) of the image.

Lights don't always burn out instantly, they can burn, which includes creating smoke. Depending on the conditions and that we're likely talking about a large filiment (like you see in the metal halide and similar industrial bulbs) it wouldn't surprise me if it burnt brightly for several seconds before (and into) when the picture was taken. This would explain seeing smoke and the bright light at the same time. Another possible explaination for the smoke is the transformer/ballist burning out (could also be cause of light), and I don't think there would be external damage visible because of this. There is also enough time between frames for the smoke to dissipate and not be seen in the next frame.

It also seems to be the appropriate time of day not just for the light to be on but to burn out (many bulbs burn out when started because of the stresses of warming up, etc). It looks like some of the lights are on, and that it's dusk/dawn. The exif headers corroborate that it is dusk (6:52pm). Dusk is when automatic lights turn on, either via light sensors (sensing dusk) or timers.

That seems a reasonable and highly-probable explanation for the smoke + light. Perfect conditions, this is what the picture appears to be of given nothing else like external damage to pole, ripples in water, etc.

I would like to see a picture from the night before and night after (they would likely show that that light is working the one day and not the next, unless the maintanance guys are quick). However, even without a working light the previous night, we could see this light/smoke from the transformer. But if the pictures show what I expect (light day before, no light next day), it would make my theory highly possible.

More on JPEG Artifacts...

"The photographer insists that the streak and flash on the above image has not been created digitally." I think it would be more correcto say that HE didn't manually create it digitally. Essentially cameras take information from the CCD and store it either in raw format, or they process it and store it in a processed format (like TIFF, JPEG, PNG, etc). JPEG is not only a processed image type, but it's a lossy image type.

Because you can get strange effects/artifacts from processing into lossy formats, camera makers try to put brains into the cameras to compensate for the artifacts. With all of this processing, strange things can happen to photos. Many professional digital photographers use special programs made by the camera manufacturers or companies like Adobe that are familiar with the propriatary RAW format produced by a given camera to convert process the picture outside of the camera so they can achieve better photographic results. Often you don't get accurate color saturation or sufficient contrast using in-camera processing...or you get additional artifacts because the camera's software people tried to make up for these shortcomings and introduced artifacts themselves.

Regardless, it is quite possible that the image captured by the CCD didn't have the "tail", but during the processing and correction the camera's algorithms added it.

This issue with the on-camera processing isn't some hair-brained idea of mine. It's such a common concern that Adobe is trying to standardize the raw format cameras use cause that will make making processing software easier as you won't have to figure out the propriatary format of each camera:
http://www.photoshopsupport.com/photosh ... e-dng.html

dpreview.com, a very respected camera review web site will compare JPEGs and such created on-camera with pictures they take raw and then process using external processing software. They're effectively reviewing/judging how good the on-camera processing is.

Regards,
Craig Latzke
http://www.latzke.us

[Brett]

Hi All,

I read a lot of repetitive stuff and finally gave up looking to see if there was someone else with this combination:

a) The light source appears to be either a run of the mill bulb explosion or, as has happened in my neighborhood on occasion, a pole-mounted transformer, arcing.
Since the series of poles of that height in the image don't have lights (as the shorter, already lit, poles do) and they lead toward an industrial-looking loading/offloading arrangement at the far right, it seems a reasonable guess to assume there might be power cables present. Additionally, the third set of poles (tallest) appear to have rectangular light fixtures aimed down. Would there be 3(!) sets of lights? Probably not. (Note that the resolution appears too low to discern for sure from this image).
A transformer arcing hypothesis also takes care of the problem of the lightsource being off-center as, if it is a transformer, it would be side-mounted on the pole. Also gone is the shadow-of-the-housing problem, as most pole-mounted lights are aimed at the ground in a 'suspended' arrangement and rarely these days are they housed in multi-panel fittings which would contain sufficiently thick 'bars' which might cast upward facing shadows into space.

b) Judging from the time-of-day and the presence of very impressive cumulo-nimbus thunderclouds in the distance, as well as cirrus formations, it also seems reasonable to assume the presence of a good deal of humidity. I checked the weather then with a google search of "darwin australia weather" and found this to be accurate. Warm and humid.

My conclusion (admittedly tenous, based on a lot of questions left unanswered): A brief, though powerful lightsource and humid air, lit by a low-angle sun all adds up to a very brief mini-rainbow. That the 'rainbow' is apparently straight is unimportant because the lens (according to earlier posts, is a ~46mm equiv.) which is quite narrow and would thus not represent a graceful arc, even if the 'rainbow' were powerful enough to project out that far.
Also, since the water is being barely tickled by a breeze in these 3 shots, the wind is all but calm, which allows for the smoke from an arcing transformer to hang around as a bit of haze in the later image as some others have pointed out.

Cheers,
Brett.

[Harry Law]

Here is my "Theory"


Excuse the spelling of flash! Paint has no spellchecker!

I am not a physicist, just thinking as how to explain this amazing picture.

Of course the light from the "Flash" is not channelled or focused just on the lamp fitting per se but is used to illustrate the crude drawing. I did not want to fill the whole picture with yellow.

It is highly unlikely what you described will cause the effect shown in the picture.

There are a few reasons. First, we will have to assume the air somehow able to absort some light to make a trail of shadow appear in mid air. Very difficult to do!

Second, we will have to assume the entire background are brighten from the flash if that happened. However, judging from the before and after picture. The picture were not brighten, only dimmed down on that trail of shadow.

[Guest]

Its a firefly zipping past very close to the lens. Perhaps caught in a gust of wind.

The firefly is too close to be in focus. It coincedently flashed its light while it was nearly inline with the little light pole. For the rest of its path ... from the upper left to the lower right, it was blocking some light, leaving what you think is a dark trail through the sky.

If it passed very close to the lens, say within a centimeter or 2, then in 1/20th of a second it could easily travel 2cm or so across the view at a speed of only 0.4m/s, appearing to streak across the sky.





Ken Lord
Vancouver BC
kenlord [at] gmail.com

I disagree , this is not a firefly . Fireflies only can be seen at night after the sun is gone down and begining just before it's totally dark . Heres my image of the Milkyway I took at Ft.Davis Tx and there are 2 fireflies at the bottom of the image . They are the projected round green glows of light . Notice there is no flares of light whatsoever from either of the 2 fireflies .
-Ron

[j2004nyc10018@yahoo.com]

Clearly there is a small ball of light in the bay closer to the photographer's perspective. In enhancement it also has it's on shadow on the water. WHAT IS THIS????????? That is the real question.

[Guest]

I like the insect theory because it fits the picture so well, but the straightness of the streak puts me off a bit. I adjusted contrast up and brightness down, then put this picture of a fly beside it...

This did it for me...I was big on the lamp theory but this photo with superimposed insect and the diff image that shows the distinct start and end of the "streak" has done it for me.. It's a bug....

[Guest]

Excellent diff picture. Certainly better than the one I did. One thing that immediately grabs me is that the "shadow" has both a beginning and an end, both within the frame. This is enough to convince me of the insect theory.

Since nobody has posted this here yet, my try at making a good diff of the pictures: http://images.isja.org/images/strange_diff_pryde_01.png

This is the diff that I spoke about in my earlier post with the bug superimposed on the darkened picture... The distinct start and end of the streak is pretty definitive that it's not a shadow..

[David K. Smith]

My guess: an insect flying close to the lens. Since the streak is dark, it suggests the shadow of a moving object that could not be "hot" (such as a meteor). The flash of light? I could envision the insect traveling in a path such that its body picked up a brief glint of sunlight just as the exposure ended.

[Dwight Thompson]

I agree with this kid in my class. He said that it could have been a plane flying by and something small just fell out the sky. But whatever fell out the sky it just lefted a diagonal streak in the sky from it falling.

[Guest]

Take the image into PhotoShop or some similar editing program, and zoom in. What I see (as others might) is:
1: the transitory shadow of a contrail (long dark streak), coindicentally appearing to end at the top of a light pole;
2: the light pole is just turning on, as dusk triggers the start up, via a light sensor; these often flare, and with a 1/20 sec. shutter speed, would leave a large bright image;
3: a utility truck is parked to the left of the light pole, and it's exhaust is trailing from it, diagonally up to the right, coincidentally near the top of the light pole.
Result: the accidental convergence of 3 unrelated phenomena.

Chris Sherman
shermanc@wustl.edu

[Guest]

It depends on what mode you are using. If you are using the normal flash mode (or flash sync) it will fire at the beginning. If you use the special nighttime assist mode (usually indicated by an icon with a person with a star behind them) it will open the shutter first and then flash at the end. This is probably because if you have motion blur, you want the blur to trail the object rather than making it look like everything moved backwards.

I tested this on a Canon Powershot S500.

Ok, that is a valid point. A night assist mode is something I never use; as it defeats the purpose of having manual settings If that is the case, then the camera would have good reason to set second-curtain sync.

[Rob Crouch]

Regardless, it is quite possible that the image captured by the CCD didn't have the "tail", but during the processing and correction the camera's algorithms added it.

I had this happen to me and it was not a double exposure, as you say digital cameras could have quirks?



I seem to have a Quantum Cat that can manupulate the space time continium and do hyperspace jumps, thereby becoming transparent.

I still lean to the idea of some bug and/or lightsource or bug on the camera processor now that it has been explained.

[phul]

I found two strange objects in the photo. 1) There is a bright white object floating just above the surface of the water in the lower left. I can also see what appears to be shadow just beneath it. 2) There is some kind of "orb" in the sky directly above the flash. I scaled up the pic and increased contrast to get a better look. See the enhanced detail pics at http://www.imageprosinc.com/dev/strange/index.html

Andy,

The small dot on the water shows up in all three photos. It is a hot pixel and is a defect in the CCD. Do a search on hot pixels in google and you will see that it is a non-starter of an issue.

[Guest]

I disagree , this is not a firefly . Fireflies only can be seen at night after the sun is gone down and begining just before it's totally dark . Heres my image of the Milkyway I took at Ft.Davis Tx and there are 2 fireflies at the bottom of the image . They are the projected round green glows of light . Notice there is no flares of light whatsoever from either of the 2 fireflies .
-Ron

But you are not firing a flash at the bug when you took the milkyway shot.

[Guest]

I had this happen to me and it was not a double exposure, as you say digital cameras could have quirks?

I seem to have a Quantum Cat that can manupulate the space time continium and do hyperspace jumps, thereby becoming transparent.

I think your picture shows something else, like that the cat's tail wasn't there for the full duration of the shutter/exposure, not an on-camera processing artifact.

Craig Latzke

[Rodmanuno@yahoo.com]

To me its seems that the Lens is more the culprit for the illusion.




Homer Castillo
Edcouch, Texas