Lightning leaders over Léman Lake (CH)

[Ken Langford]

Originally Posted by Oscar van der Velde

I generally agree with Jeff, Dan and Mike.

1. If camera shake caused this, if there would be just 1 upward catching streamer it would appeared smeared like in those Boys camera photos. We don't see this. Why would such a streamer pulse?

3. The 4 do indeed not take the same path as each other.

4. The camera shake must be very fast at the exact moment of the strike (starting actually just before). This would seem impossible to do, so it appears that the movement was either before or after the flash, or both, but not all during the exact moment of the flash. The motion of the many lights in the distance was wiggly and also in vertical direction which would have displaced the leader over maximally the same angular distance. This may match horizontally indeed, but not vertically! Rather, the return stroke highlights the water surface, which is at equal level with the leaders. If the camera motion had any effect on the lightning this would have been impossible. So, the motion of the camera was too slow to cause an effect on the lightning itself.

5. Also the *downward* leader would have to be similarly displaced like in a Boys camera streak photograph. One cannot see it (the diffuse effect is coming from internal reflections in the lens). So again, the motion of the camera was too slow to cause an effect on the lightning itself.

Conclusion: The camera shake had too slow speed to separate the lightning processes: the 3 streamers are real and unique from each other.
It would have been perfect if the camera remained steady so that nobody would need a whole discussion to believe it.....

Oscar

Sorry for coming into the discussion so tardily!

I believe that this excellent photo shows three separate streamers (upward moving unconnected leaders, to quote the Uman/Rakov book).

In addition to the points cited by Oscar van der Velde, I should like to point out that the buoy is clear evidence of three streamers. If the image was of a single electrical discharge which was separated in time by camera motion, then the buoy would appear four times: once for each pulse represented in the frame. Each pulse is bright enough to illuminate the buoy, so the only conclusion I can draw from the single buoy is that the image depicts four discharges around a single buoy.

I'd also like to comment that this is only the third image I have seen which depicts any branching on a streamer, and it is certainly the clearest of the three (the others being lightning on a NJ beach and Autery's excellent tree image).

Finally, this is the only image I have seen in which more than two streamers are visible in close proximity to the main lightning flash.

Dan also mentioned the small projection which appears attached to the buoy. While I have nothing to support my opinion, I suspect that this is some non-electrical artifact. This hunch is based mostly on its magnitude of illumination, and the "L" shape just above the buoy. It just looks different than the others in a way that makes me think it is not related.

I hope this helps the discussion!

Ken

[Paul Austin]

Originally Posted by Ken Langford

...If the image was of a single electrical discharge which was separated in time by camera motion, then the buoy would appear four times: once for each pulse represented in the frame. Each pulse is bright enough to illuminate the buoy, so the only conclusion I can draw from the single buoy is that the image depicts four discharges around a single buoy.Ken

Exactly what I was thinking. The camera shake depicted by the lights along the shore looks to me to be either a bump at the end of the exposure with the lens traveling down and toward the right, or more likely, the camera quickly settling into its still position immediately after the shutter release (lens shifting up and to the left). This is difficult to avoid without the use of some type of remote release. Even on a tripod, pressure from a finger on the release can position the camera out of its angle of rest.

It also appears that the closest non-discharged leader has attracted a branch from the main channel of the discharge. In two dimensions it's impossible to be sure. It would appear, though, that the "choice" was very "difficult". That's the only way I could think of to put it.

Marvelous and extremely fortunate catch!

[Tomas Pucik]

Well, I have a similar photo to post that actually depicts lightning streamers or a returns strokes. Have a good look at the streamers rising upwards from the tree tops in close proximity to the actual bolt. I think it is very similar situation to the lighting leaders over Léman Lake posted some time ago. Just a note, it was taken this July in Czech republic.
Oops, the uploaded picture is too small to see details, so follow this link:
http://ukazy.astro.cz/gal/20070720Ma...ke_blesk2a.jpg

[Paul Austin]

Wow, Tomas!

Another marvelous catch! I don't think there's any question there.

[Dan Robinson]

Awesome shot, Tomas! Looks like FIVE definate leaders there - wow. It looks like you can see a little bit of the lightning channel traveling down a tree near the ground, showing through the trees.

There are only a handful of stills in existence showing CG-associated upward leaders, so this (and the original photo posted in this thread) are very remarkable.

[Jeff Miller]

Remarkable and rare footage - great shot and one you should be very, very proud of to say the least. It's amazing to watch those leaders charge upwards from the tree... Marvelous shot!!!!

[Ken Langford]

Originally Posted by Tomas Pucik

Well, I have a similar photo to post that actually depicts lightning streamers or a returns strokes. Just a note, it was taken this July in Czech republic.
follow this link:
http://ukazy.astro.cz/gal/20070720Ma...ke_blesk2a.jpg

Hi Tomas,

Fantastic! It's a great time to be a lightning enthusiast, with all these great shots surfacing!

Just to clarify, it looks like the shot was captured by Pecka Marek on 07-20-2007... is this correct? Can we get a full description of the event (location, time, circumstances)? Thanks for posting this!

Ken Langford

[Tomas Pucik]

Unfortunately, I do not have any detailed description how this guy shot the ligthning but obviously he was waiting actually to shoot stars! He did not get the shot of stars ( he is amateur astronomer) instead there was a storm and lightning hit approximately 300meters away from him. No need to say, you can see how unsafely was the guy acting ( did not have car or anything nearby to take cover in and seems to be standing or relatively high ground) He was using Canon EOS 20D with 15seconds exposure, ISO 200, f8.
I came across this photo only recently on webpage dedicated to amateur astronomers and was absolutely stunned. It reminded me of this topic and decided to post his picture ( I was really thinking a lot whether it actually can do such thing- well he does not seem to put copyright or anything on it - probably this picture does not seem important to him :-D) because it is a wonderful example of those streamers.
It is quite ironic, some of lightning photographers have to wait years and try hard to get such a shot and this man did not even intend to shoot storms.