Strange streak discussion: 2004 Dec 7 APOD

[Richard H]

Actually, this is most likely not debris from space... rather, debris from within the atmosphere. This is what happens when two 'rods' engage in a dog fight. You are seeing the loser plummet to the ground, in a blazing death dive. Small enough, fast enough... this explains it all. The loser of the dogfight is probably vaporized and so you won't find any real debris on the wharf. This is a common thing... these 'rods' come from the opposite side of Mars that the face is on. We call it, the butt of mars. These rods fly out of the mars butt and clog our atmosphere while enaged in making crop circles. I'm glad to see we're 'one less rod'... they're such a nuisance. Those, and the orbs. I hate them.

[quasar]

when you don't have a decent http place to post pics for inclusion in these types of forums ... regrets

[guest]

Rodman... this is obviously one of your miniature bricks aka airball

[FastArtCeeToo]

Very nice image! What program... photoshop?

I've been loose in my language. Yes, the flash is not centered on the body of water (I never meant that it was), and, yes, the line of reflection seems to extend to just above the far shore. But the bottom end of the line appears to end at the wharf... exactly where a reflection in the water would end.

Overall -- as shown in the small images in post that follows your post -- the position of the reflection phenomenon *almost* corresponds exactly to the extent of the body of water. This would be quite a coincidence if it's a bug.

The 'wings' of the bug would also have had to be caught when they were aligned, because the reflection line, on either side of the flash, is in a straight line. *Another* coincidence if it's a bug.

If it's a four-winged bug, either the two sets of wings would have had to be exactly aligned, because there is only one reflection line. *Another* coincidence?

I don't offhand know why the top end of the reflection line appears to extend above the far edge of water... but it's NOT a bug. Too many coincidences.

One last point (maybe in your favour): In your image, there *seems* to be a very faint, lighter, line above and parallel to the dark streak. Any ideas? (Too bad these are jpegs; I take it there are no uncompressed versions?)

By the way, can you tell me the time/date/orientation of the photo of the streak phenomenon? Thanks.

[Bob Peterson]

Here's the camera: http://www.dpreview.com/reviews/canong3/. It's time for a diagonal streak produced by a BUG. Go to it boys and girls. Don't forget to wear your bee suit. Do your best to duplicate the variables.

[FastArtCeeToo]

The hint of a faint lighter line is *below* the streak, not above, as I mis-said in my previous post.

[guest]

DANDRUFF

[victorengel]

Overall -- as shown in the small images in post that follows your post -- the position of the reflection phenomenon *almost* corresponds exactly to the extent of the body of water. This would be quite a coincidence if it's a bug.

And it would be impossible if it were a reflection in the water.

The 'wings' of the bug would also have had to be caught when they were aligned, because the reflection line, on either side of the flash, is in a straight line. *Another* coincidence if it's a bug.

First, the two "reflections" are NOT aligned. They're close, but a couple degrees apart. Second, and I don't think this is getting through to people, although the strobe of a camera is brief, it is not instantaneous. The exposure records a period of time. If this period of time is long enough, relative to the event, substantial motion blur can result. If we're talking about insect wings, part of a wing stroke up to several wing strokes could be recorded. How much of a wing stroke is recorded depends upon the flash duration (we don't know that yet) and the flapping frequency (we don't know that either). Camera flash is typically in the range from 1/1000 to 1/10000 second. Insect wingbeats can be from 1/10 second to 1/60000 second. The consensus speculation here is that the flash was 1/1000 second and the wingbeet 1/200 second. That would mean 1/5 of a full wingflap cycle is recorded. That is plenty of time for the two wings to have been recorded at different time points in the flapping cycle.

If it's a four-winged bug, either the two sets of wings would have had to be exactly aligned, because there is only one reflection line. *Another* coincidence?

If it's a four winged bug, it's likely that the top wing on one side was roughly aligned with the bottom wing on the other side. That actually happens a lot.

By the way, can you tell me the time/date/orientation of the photo of the streak phenomenon? Thanks.

I'm not sure what you mean by orientation. It's landscape, but that's obvious, so I suspect you mean something else. The EXIF data shows the picture was taken at 11/22/2004 18:52:52/. This, of course, rules out any coincidence with the December meteor.

[Guest]

Here's the camera: http://www.dpreview.com/reviews/canong3/. It's time for a diagonal streak produced by a BUG. Go to it boys and girls. Don't forget to wear your bee suit. Do your best to duplicate the variables.

Easiest would be for the original photographer to provide access to the images either side of the 3 we have access to - I bet we'd find a few trails on at least some of them.

[deviante]

wtf are you people looking at? i don't even see anything in the picture worth talking about. it's a bad picture of nothing.

[Guest]

wtf are you people looking at? i don't even see anything in the picture worth talking about. it's a bad picture of nothing.

You are either using AOL or are colour blind

[redxeth]

All right!

Everyone say their peace now-- can we resolve this before the end of page 100?

I think not 8)

I can't wait to see APOD update.

Been enjoying watching the flexing of so much intellectual muscle (and some flab too).

Dan

[Bob Peterson]

And speaking of all the variables we'll never know, take a look at the tech info on the Canon PowerShot G3. I'm putting this URL up again:http://www.dpreview.com/reviews/canong3/. The other thing is that I just wanted to be on page 100.

[victorengel]

And speaking of all the variables we'll never know, take a look at the tech info on the Canon PowerShot G3. I'm putting this URL up again:http://www.dpreview.com/reviews/canong3/. The other thing is that I just wanted to be on page 100.

I've sent an email to a Canon tech who used to post regularly at dpreview. I hope he weighs in on the technical details of the flash issues.

[Jimmy Jet]

are we so sure that it is/or was the light pole? to me it looks like it hit in the distance, out in the water some where. but i have no idea what it could be. lets think out side the box and get off the pole.

[Guest]

The experimental apparatus:



The subject (I would have asked consent, but it was dead already (the geographical location was approximately under the sofa in the front room).



At this point, trial runs were performed on the apparatus using a cheap digital camera focused on infinity and flash set to 'synchro' (a flash and a slow exposure, as per the original image).

During one of these trial runs, the experimental setup suffered a gravitional catastrophe following a particular inept attempt by the experimenter to get some serious RPM onto the Mavic 519 bicycle rim with Shimano XT hub (silver, not shown). As a result, the subject suffered total disintegration (well, it had been under the sofa since last summer - dust to dust, and all that).

Fortunately, a portion of yellow cardboard was available (from the experimenters frozen dinner packet) and was willing to stand in (at least, it didn't actually object when I skewered it with an old bicycle spoke).

Experiment duration was approximately 15 minutes and was curtailed by the smoke alarm (due to unplanned combustion of the experimentalist's dinner). The results were later examined, and the following image selected as representative.

[J Joy]

And speaking of all the variables we'll never know, take a look at the tech info on the Canon PowerShot G3. I'm putting this URL up again:http://www.dpreview.com/reviews/canong3/.

I've found someone at Canon Support who might be able to answer questions about the PowerShot G3 and the EXIF data. By policy, Canon Support can't participate directly in the discussion group. If anyone has specific questions on the G3 and EXIF, please post them - and please be concise - I'll compile and send them on to this guy (Anthony), and we'll see what we get back. I'll give it 24 hours to collect questions.

Thanks,

JJ

[victorengel]

The subject (I would have asked consent, but it was dead already (the geographical location was approximately under the sofa in the front room).

I was ROFL as I read your post. If you are serious about this line of experimentation I have a major change to suggest: try to set up your apparatus so that something at infinity is in the background. That may mean taking your bicycle parts to the top of a hill or something. If you find another suitable subject, you might try rotating him or changing camera position to get different perspectives of the wings....

[Guest]

If you are serious about this line of experimentation I have a major change to suggest: try to set up your apparatus so that something at infinity is in the background.

Note I did set the focus at infinity (it's a cheap camera, but it's got a manual focus setting and I used it); I'd have put an image at infinity to prove it, but my front room isn't *that* big.

[victorengel]

I've found someone at Canon Support who might be able to answer questions about the PowerShot G3 and the EXIF data. By policy, Canon Support can't participate directly in the discussion group. If anyone has specific questions on the G3 and EXIF, please post them - and please be concise - I'll compile and send them on to this guy (Anthony), and we'll see what we get back. I'll give it 24 hours to collect questions.

Did the flash indeed fire during exposure?
Was it 1st curtain or 2nd curtain sync?
What was the duration of the flash?
What distance would the subject have to be to get a proper exposure for this flash duration?
What distance was the lens set to?
What was the ISO used?

And one final one if someone with a G3 wants to do experimentation:
What settings need to be made on the camera in order to duplicate the exposure?

[victorengel]

If you are serious about this line of experimentation I have a major change to suggest: try to set up your apparatus so that something at infinity is in the background.

Note I did set the focus at infinity (it's a cheap camera, but it's got a manual focus setting and I used it); I'd have put an image at infinity to prove it, but my front room isn't *that* big.

Yes, I saw that you stated that. My point about infinity had more to do with the effect of the flash than on focus. In your example, the background is being illuminated by the flash. In the study picture that is not the case (at least not significantly).

[Guest]

My point about infinity had more to do with the effect of the flash than on focus. In your example, the background is being illuminated by the flash. In the study picture that is not the case (at least not significantly).

Sure, there's some backscatter, particularly off the rim (but if I'd used a longer support it would have hit the brace on the bicycle fork). Anyway, it's not a quantitative experiment; just a proof of principle.

By the way, the wheel rotation was anticlockwise - so on the camera I used, the flash evidently occurs at the start of the exposure (rather than the end).

[H0meAl0ne]

My point about infinity had more to do with the effect of the flash than on focus. In your example, the background is being illuminated by the flash. In the study picture that is not the case (at least not significantly).

Sure, there's some backscatter, particularly off the rim ... it's not a quantitative experiment; just a proof of principle.

We are interested in a situation where you have a small object close to the lens and the rest of the scene being photographed at what is effectively infinity for a flash.

The overall brightness of the picture will hardly be affected by the flash, so the shutter speed and aperture will not be changed much (if at all) and the picture will be correctly exposed. The small object close to the flash will then be overexposed, as it reflects so much light.

This is true both of cheap cameras (no monitoring of the exposure and no control over the power of the flash) and to a lesser extent of expensive ones (where the total amount of reflected light is monitored and the output of the flash is controlled). Maybe on an expensive camera with the flash output monitored it may actually result in a longer flash, as the camera allows more light to be collected. That would allow the close subject to blur even more.

Maybe if you had a darker, non-reflective backdrop and took your exposure from that.

[Chroe Magnonn]

Overall -- as shown in the small images in post that follows your post -- the position of the reflection phenomenon *almost* corresponds exactly to the extent of the body of water. This would be quite a coincidence if it's a bug.

And it would be impossible if it were a reflection in the water.


First, the two "reflections" are NOT aligned. They're close, but a couple degrees apart. Second, and I don't think this is getting through to people,
.

Well, that's exactly what I said when I proposed this was a photoshopped image... duh!!!

[Rocky Jones]

Dad said I should fess up here. It was me. I shot a hobby rocket, with Estes engines, from the wharf. I had to run off, the harbor patrol started chasing me. Sorry.