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farmerjumperdon
2007-Oct-19, 12:09 PM
With the interest in aviation here I thought some light enjoy this snapshot.

I really dig being near a good low pass. I've bee close enough a couple times to have to duck the landing gear. Way cool.

Stuart van Onselen
2007-Oct-19, 12:29 PM
If that pic is for real, doesn't the pilot owe a couple of boat-owners the price of new glazing? Being that close to a sonic boom can not be pleasant for ear-drums, either!

Moose
2007-Oct-19, 12:45 PM
If that pic is for real, doesn't the pilot owe a couple of boat-owners the price of new glazing? Being that close to a sonic boom can not be pleasant for ear-drums, either!

That's not a sonic boom. It's humid air condensing very rapidly due to the compression wave. The F-18 is not going supersonic.

But yes, had the F-18 been supersonic at that moment, the boats would all be in the process of taking shock damage, having their glass shattered, etc. There'd be fish floating to the surface, stunned, too.

farmerjumperdon
2007-Oct-19, 01:02 PM
Yes, the pass was definitely subsonic, but my source did not give the speed.

A neat little detail is the condensation occuring around the cockpit bubble.

NEOWatcher
2007-Oct-19, 01:22 PM
A neat little detail is the condensation occuring around the cockpit bubble.
I just the the pilot was fuming. :shifty:

Larry Jacks
2007-Oct-19, 01:28 PM
That looks like a PhotoShop composite instead of a real photograph.

ozzmosis
2007-Oct-19, 03:26 PM
yep photoshop all over but nice pic never the less

farmerjumperdon
2007-Oct-19, 04:17 PM
yep photoshop all over but nice pic never the less

I wondered, but don't know how to tell. What gives it away?

NEOWatcher
2007-Oct-19, 04:27 PM
I wondered, but don't know how to tell. What gives it away?
Ditto;
My first thought was the symmetry of the condensation cone being so close to the surface.

Larry Jacks
2007-Oct-19, 04:44 PM
Here's the photo in a Daily Mail article (http://www.dailymail.co.uk/pages/live/articles/news/worldnews.html?in_article_id=486395&in_page_id=1811), so perhaps it's real.

What made me question the photo is that military teams rarely fly that low that close to spectators. It also looked too much like other photos I remember seeing.

Swift
2007-Oct-19, 04:49 PM
I wonder how close it really is to the boats and spectators. It looks like the photo was taken with a very long telephoto lense, which really change the depth perception.

NEOWatcher
2007-Oct-19, 04:58 PM
I wonder how close it really is to the boats and spectators. It looks like the photo was taken with a very long telephoto lense, which really change the depth perception.
I agree... especially looking at the scale of the foreground black boat and the background white boat.

Anyway; what is the SF layout of the air show? We have a similar situation with Cleveland's air show being at our lakefront airport. There is a buffer zone, but on approach and departure, they can be rather low to the water.

In fact, I was once at a Brown's game at the old stadium during an air show, and the entire game stopped when a B52 came in. (at least it wasn't the middle of a play)

hhEb09'1
2007-Oct-19, 05:28 PM
I wondered, but don't know how to tell. What gives it away?The shadows are wrong :)

ozzmosis
2007-Oct-19, 05:34 PM
first of the pic should be all in focus, why is the plane in focus and the rest out of focus, if anything the plane should be out of focus couse its moving that fast, i taken a few pics while moving in a car and what ever i took a pic of was in focus and what ever was around was too

hhEb09'1
2007-Oct-19, 05:36 PM
first of the pic should be all in focus, why is the plane in focus and the rest out of focus, if anything the plane should be out of focus couse its moving that fast, i taken a few pics while moving in a car and what ever i took a pic of was in focus and what ever was around was tooThe depth of field could be centered on the plane, which would make everything else out of focus, but it looks more like the camera was supposed to be tracking the plane--which means the plane would have been in focus, but the rest would have shown blur from movement.

Looking at the photo, it does look like there are two distinct copies of the masts/vertical lines. That could easily have been photoshopped as well though.

PS: the official Blue Angel website (http://www.blueangels.navy.mil/index.htm) lists a show on Oct. 6/7 in San Francisco. That matches the Daily Mail article (http://www.dailymail.co.uk/pages/live/articles/news/worldnews.html?in_article_id=486395&in_page_id=1811).

NEOWatcher
2007-Oct-19, 05:39 PM
...i taken a few pics while moving in a car and what ever i took a pic of was in focus and what ever was around was too
I seem to be under the impression that an F-18 is a bit faster than a car. :think:
Besides; picture from a moving object is different than a picture of a moving object because from means that all objects (at depth) are tracking at the same speed.
I can see the effect if the cameraman is extremely skilled at tracking the object (like a hunter leading the prey). But; I don't know if this particular effect is possible.

The_Radiation_Specialist
2007-Oct-19, 06:10 PM
Opening the file with notepad gives:


JFIF  d d Ducky   < Adobe d 

I'm not sure what it would mean but the word Adobe there is suspicious.

Could've been enhanced with Photoshop though..

NEOWatcher
2007-Oct-19, 06:28 PM
I'm not sure what it would mean but the word Adobe there is suspicious.
Well, if that ain't just ducky. http://www.cosgan.de/images/smilie/tiere/g080.gif

SeanF
2007-Oct-19, 06:31 PM
Here (http://jumpcut.com/view?id=C009AF72755211DC9F89000423CF037A&u_id=&them=1) is some video of a similar (the same?) flight.

Larry Jacks
2007-Oct-19, 06:36 PM
Smoking!

Moose
2007-Oct-19, 06:46 PM
It's pretty clear from the aspect that the image was either cropped from more typical resolutions, compressed (jpged) from a non-lossy format in order to make it web-convenient, or scanned from a wide-angle film print. The Adobe reference in the jpeg does not, on its own, indicate shenanigans.

To dismiss this as a 'chop based on nothing more than a casual glance commits the same logical fallacy (personal incredulity) that HBers display when dismissing Apollo photos because they don't understand how photography works.

I have seen tracking shots where the foreground object was sharply focussed while background objects were motion-blurred, much like this one. (A good equivalent for a GIS might be stills of F1, NASCAR, or drag racing events. Aviation.net is also a good place to look for equivalents.)

Remember, the camera is tracking the F-18, and is probably using fast film and has the F-stop set for this sort of shot. The F-18 is motionless (in a relative sense). The other objects are moving rapidly (from the reference of the F-18).

I can't reproduce the shot with any camera I own (one film, one digital, both of which are cheapy low-end dummy-proof layperson cameras.) And I'm not familiar enough with camera settings to describe what might have been done.

But I have seen analogous shots. I think the evidence currently presented (virtually none) does not support rejecting the photo as faked.

hhEb09'1
2007-Oct-19, 06:50 PM
Here (http://jumpcut.com/view?id=C009AF72755211DC9F89000423CF037A&u_id=&them=1) is some video of a similar (the same?) flight.I couldn't find the same surrounding ships, but it would've been the same Fleet Week in SF.

Notice how, when you pause the video, you see a doubling up of the ship images. :)

Trebuchet
2007-Oct-19, 07:20 PM
I couldn't find the same surrounding ships, but it would've been the same Fleet Week in SF.

Notice how, when you pause the video, you see a doubling up of the ship images. :)

I think I see the same red/white fireboat (?) about half way through. The vantage point of the photo would appear to be further to the right than that of the video.

Slightly OT, but what causes that doubling up? My friend froze some frames out of a video of our trebuchet hurling a pumpkin. Each shows two slings & pumpkins. It's as if the camera was operating at 60fps but combining pairs of frames into single ones to get 30 fps. Does that make sense?

NEOWatcher
2007-Oct-19, 07:26 PM
I think I see the same red/white fireboat (?) about half way through. The vantage point of the photo would appear to be further to the right than that of the video.
I think its from the other shore. The foreground sailboats in the picture could be the two that are right of the fireboat at about the same distance in the opening shot of the video.
And the boats in the background could be off camera to the left in the same frame(s)
It looks like the front of the fireboat in the picture, and the rear in the video.

SeanF
2007-Oct-19, 07:28 PM
It's as if the camera was operating at 60fps but combining pairs of frames into single ones to get 30 fps. Does that make sense?
Not only does it make sense, it's exactly what happens. NTSC standard is 60 fields per second, interlaced. That is, each "frame" is 480 scanlines tall, but the system scans all the odd-numbered lines in the first 60th of a second, and then all the even-numbered lines in the next 60th of a second.

So if there's a lot of motion in that 60th of a second, alternating lines can be quite different.


I think its from the other shore.
If that were the case, the plane would be going right-to-left in one of them.

Moose
2007-Oct-19, 07:28 PM
Slightly OT, but what causes that doubling up? My friend froze some frames out of a video of our trebuchet hurling a pumpkin. Each shows two slings & pumpkins. It's as if the camera was operating at 60fps but combining pairs of frames into single ones to get 30 fps. Does that make sense?

Yes. It's called interlacing (http://en.wikipedia.org/wiki/Interlacing).

SeanF
2007-Oct-19, 07:30 PM
Yes. It's called interlacing (http://en.wikipedia.org/wiki/Interlacing).
Beat ya. ;)

NEOWatcher
2007-Oct-19, 07:34 PM
...interlaced....
Simple enough for me...

If that were the case, the plane would be going right-to-left in one of them.
Interesting...So is that what would happen if I could see my image in a mirror? :doh:

Moose
2007-Oct-19, 07:34 PM
You did indeed, SeanF. Once again, I am forced to choose between donning the Kirkian Toupe of Shame or the Kirkian Man-Girdle of Woe.

Decisions, decisions.

hhEb09'1
2007-Oct-19, 07:58 PM
I think I see the same red/white fireboat (?) about half way through. I noticed that, and looked into SF fireboats. It looks like there are only two, the one in the OP photo looks like the Guardian (http://www.answers.com/topic/fireboat), the one in the video I'm not so sure about. It doesn't seem to have the same tower, but it's not exactly the Phoenix either. Maybe a police boat??

Trebuchet
2007-Oct-19, 09:32 PM
Thanks for the interlace explanation guys, I should have thought of that. Now I can pull out those trebuchet pictures and calculate the velocity of the pumpkin with some reasonable degree of accuracy!

The fireboat and plane are pointing the same direction (to the right) in both the movie and still. I'd guess the still may have been taken from the one of the two docks off to the right of the movie photographer.

The fireboat does look consistent to me. Red hull and lower superstructure, white pilot house and tower, red firefighting position on top of the tower. I'd say the Guardian looks correct.

hhEb09'1
2007-Oct-19, 10:17 PM
If that were the case, the plane would be going right-to-left in one of them.If it were the same flight of the same plane :)

But I'm pretty sure the opposite shore visible in the OP photo can be seen in the movie

red firefighting position on top of the tower. I'd say the Guardian looks correct.The red position on top just looks too skinny in the video, that's all. I dunno

Trebuchet
2007-Oct-19, 10:37 PM
I think the firefighting position may look skinny due to an interlace effect. You're basically seeing half of it in two different places. Or not. I dunno either!

I looked in Google Earth and think I found the curving pier. The next one beyond it appears to be just a breakwater. I'd bet the still was taken from the curving one.

01101001
2007-Oct-19, 11:10 PM
I looked in Google Earth and think I found the curving pier.

Looked like Aquatic Park (Google Map Satellite (http://maps.google.com/maps?f=q&hl=en&geocode=&time=&date=&ttype=&sll=37.296247,-122.015104&sspn=0.029975,0.06403&ie=UTF8&ll=37.80858,-122.42413&spn=0.014885,0.032015&t=k&z=15&om=1)) to me.

Trebuchet
2007-Oct-20, 12:04 AM
Yes, that's the one I was looking at.

hhEb09'1
2007-Oct-20, 03:01 AM
YouTube:

video one (http://www.youtube.com/watch?v=JbcDhh3OYVg&mode=related&search=Blue%20Angels%20Fleet%20Week%202007%20San%2 0Francisco
) under the bridge, maybe the first part of the pass

video two (http://www.youtube.com/watch?v=iRGacDGUGtE&mode=related&search=Blue%20Angels%20Fleet%20Week%202007%20San%2 0Francisco) reverse angle flyby

video three (http://www.youtube.com/watch?v=9OxRb9jvOSo) lengthy comilation of many different passes, from deck of a boat

The_Radiation_Specialist
2007-Oct-22, 04:38 PM
Some more cool passes.

http://www.metacafe.com/watch/879584/the_craziest_low_passes_ever/

jumbo
2007-Oct-23, 12:26 AM
Very nice pic of a low pass. Definitely subsonic though as mentioned. Ive seen an F16 do similar at very very close to Mach 1 and there was more of a delay between the pass and the sound of the pass than in the youtube clips.
The original picture is showing a nice Prandtl-Glauert singularity (i think!). They are often very symmetric and one thing for me that says its real is the prescense of the vapour around the cockpit which is common on the F18 flying like this. Its something i think a photoshopper could easily miss.