Unconvincing lens flare explanation

[Timothy]

Regarding the carpark "UFO" photo in the February 15, 2008 SWIFT:

Randi's explanation of lens flare and the precise nature of the light source causing it doesn't adequately explain the artifact in the image.

Lens flares are formed when internal components of the lens act as sources, either by scatter or by reflection. For this discussion we're talking about multiple reflections from lens surfaces.

Flares in an axially symmetrical lens caused by in-field sources will form on a line joining the source and the optical axis of the lens. They can be formed by reflections from the entire circular aperture of various lens elements ( http://www.luminous-landscape.com/tutorials/flare.shtml is an excellent and beautiful example ) or can be limited by the aperture stop of the system, in which case the flare will be a polygon with 5, 6, or 7 sides depending on the number of leaves the camera's iris has ( http://www.ghostresearch.org/ghostpics/fake/Lensfl.html ).

In the first case, the axis of symmetry of the flare points towards the source; in the second the orientation of the iris may be random, but there are often multiple images of the iris, a line through the centers of which point toward the source.

In the "UFO" photo, the axis of symmetry of the artifact does not point towards the bright streetlight at the left, it's vertical (tipped a couple degrees CCW). There's no significantly bright light source along the axis of symmetry to account for it. In addition, the edges look sharp with no characteristic comatic tail as would be expected.

I have seen instances where a dim reflection of bright lights in an image can appear flipped symmetrically across the center of the lens. (Note that this is different from a lens flare -- in a lens flare the lens itself is the source -- this is a reimaging of the object.) There is a famous 1950s photograph of UFOs in formation over the Capitol at night that turns out with a few seconds observation to be nothing more than a multiple reflection of an array of streetlamps in front of the Capitol. Most online pictures of this closely crop the photo to delete the streetlamps ( http://www.ufocasebook.com/washingtondc1952.jpg ). It may be that the artifact is a reflection of the streetlamp fixture itself, flipped about the origin, and only visible because the tiny amount of reflection has decreased the intensity so it's not highly saturated.

But it just doesn't look like a streetlamp to me. Photos of the same scene in daylight would be helpful.

The only other helpful clue is the text of the article. "The 28-year-old took the photograph near his home in Portsmouth while driving home from work in thick fog." If taken through a window of his vehicle, reflections from that surface could be responsible, since the unknown angle could have reflected sources from a variety of directions including behind the camera.

[rjh01]

It could have been dust on either the camera or the window.

[Timothy]

It could have been dust on either the camera or the window.

Ummm ... no. Read up on "depth of field."

[Brown]

But it just doesn't look like a streetlamp to me. Photos of the same scene in daylight would be helpful.I concur that photos of the lamp would be helpful. If indeed the lamps are the same shape as the "craft," this would be a pretty good indicator that we have some sort of lamp-related artifact generated by the optics, and not an actual flying object.

[robinson]

The Ministry of Defence said it could not check if there were any aircraft in the vicinity at the time.

Why do the Brits spell stuff funny?

[Terry]

Why do the Brits spell stuff funny?

They don't. Americans do.

[robinson]

What? No way.

The way those Brits act, you might think they invented the language.

[wahrheit]

That has got to be one tiny UFO hovering over Portsmouth. The Sun has published a slightly higher resolution image: http://img.thesun.co.uk/multimedia/archive/00435/UFO-solent682_435100a.jpg

With such thick fog, but the "UFO" being clearly visible, it can not be too far away from the photographer. This certainly is not a space ship, more like a one meter across whatever thingy.

And so came the day when the crew of a tiny disc-shaped UFO, from a civilization far far away, was bored to death hanging around in Earth's orbit. One said, "Hey, come on. Let's burn some gas and fly to South East England!"

"A great idea, let's go", and they blasted off. Portsmouth was reached within minutes, and then they saw it: the parking lot.

"That's it! That's where I want to go, look over there, a parking lot!"

"Yeah, I so love parking lots. And it's such a beautiful, foggy night — maybe someone takes a picture of us and publishes it!"

"That would be fantastic! And don't forget to turn on the position light, I want us to be seen this time. A pale red would fit the scenery, what do you think?"

"Done. Let it blink?"

"No, not today. We'll do that maybe next time."


Seriously, no matter how real or fake one of these alleged UFO photographs might be — how in the world could anybody even remotely consider that our alien friends would do such things as hang around over a Portsmouth parking lot in their shiny round little UFO, too stupid to avoid getting photographed, but smart enough to avoid a real close-up, high quality picture?

I just don't get it.

[jimbob]

What? No way.

The way those Brits act, you might think they invented the language.

No, we just moved on from the seventeenth century

[robinson]

Yeah, and invented the Internets!

[jimbob]

Yeah, and invented teh Internets!

Fixed it for you.

[korenyx]

It looks like bad Photoshop.

[Miss Whiplash]

Judging by the angle the UFO appears, I believe this is just a flaw in the lens. Normally it would not be visible, but this photo is a photographer's nightmare. Light from the overexposed streetlights is bouncing all around in the lens elements. I'd like to know what camera and lens the guy was using.

[Timothy]

It looks like bad Photoshop.
Can you explain precisely what makes it look like bad Photoshop? I see no evidence of an altered image, much less obvious alteration. The "Photoshop" explanation appears to be a common offhand response to any unusual image ... it's the skeptic's dogmatic response, often given without careful investigation of the image. (See http://forums.randi.org/showthread.php?t=56693 and http://forums.randi.org/showthread.php?t=55859 for threads in which "Photoshop" was immediately invoked, only to be shown later that the images were easily explained by the circumstances of the photograph.)

Judging by the angle the UFO appears, I believe this is just a flaw in the lens. Normally it would not be visible, but this photo is a photographer's nightmare. Light from the overexposed streetlights is bouncing all around in the lens elements. I'd like to know what camera and lens the guy was using.
Again, this canard comes up often with unexplained artifacts on images. Unless the camera has an intermediate focal plane near one of the lens surfaces (and I know of no commonly available commercial lenses for amateur photography that do) it is IMPOSSIBLE for a chip, fleck, speck, smudge, hair, dust mote, or the like on the surface of any lens to produce an in-focus, sharp edged artifact.

Please see previous discussion and http://forums.randi.org/showpost.php?p=2474838&postcount=80 and my challenge to actually produce a distinct image on a commercial camera with an object on the front surface of the lens.

Okay, I'll concede that there is one possible explanation ... a water droplet on the front surface of the lens could act as a small lens to produce a virtual source of the bright streetlamp that would then be involved in the multiple reflections from lens surfaces, but that falls into the category of the original explanation. But the water droplet itself is not imaged.

[Miss Whiplash]

[QUOTE=Timothy;3450954]
Again, this canard comes up often with unexplained artifacts on images. Unless the camera has an intermediate focal plane near one of the lens surfaces (and I know of no commonly available commercial lenses for amateur photography that do) it is IMPOSSIBLE for a chip, fleck, speck, smudge, hair, dust mote, or the like on the surface of any lens to produce an in-focus, sharp edged artifact.[QUOTE]

It's not sharp edged or in focus. When a photograph's size is reduced, fuzzy objects appear sharper.

These artifacts pop up depending upon the angle of light entering the lens, the focal plane of the lens and the quality of the lens surface. Here the object is off axis. As it appears at such an angle, it can also be "coma"- geometric shapes caused by the curvature of the lens. It's quite common in cheap digital cameras with short focal length lenses. It still arises from poor grinding of the lens.

I must ask if you are a pro photographer. I've been photographing for 20 years and, yes, at times I get odd things when light is at a certain angle. But everytime, it's an in camera problem and not something supernatural.

[LTC8K6]

I really don't think it looks much like a lens flare, either.

I think it has navigation lights, and we probably have a longish exposure time, so I think it's a blurred aircraft.

[LTC8K6]

http://www.youtube.com/watch?v=brTfr35f7FY

Kinda reminds me of the diamond UFO's caused by the camera's aperture curtain and a point light source.

[Miss Whiplash]

http://www.youtube.com/watch?v=brTfr35f7FY

Kinda reminds me of the diamond UFO's caused by the camera's aperture curtain and a point light source.

After looking at it again, yes it does. A Sony Cybershot has a diamond shaped aperture. I remember Orbs by the Beans (http://www.orbsbybeans.com/)hailed this as some new interdimensional wonder until the camera died.

[Timothy]

It's not sharp edged or in focus. When a photograph's size is reduced, fuzzy objects appear sharper.

We disagree. I contend that this artifact, ( http://img.metro.co.uk/i/pix/2008/02/UFOCloseSOLENT_450x300.jpg ) approximately 1/40 the extent of the larger image shown has relatively sharp edges -- sharper than would be caused by aberration or lens flare.

These artifacts pop up depending upon the angle of light entering the lens, the focal plane of the lens and the quality of the lens surface. Here the object is off axis. As it appears at such an angle, it can also be "coma"- geometric shapes caused by the curvature of the lens. It's quite common in cheap digital cameras with short focal length lenses. It still arises from poor grinding of the lens.
Coma isn't simply "shapes caused by the curvature of the lens." It's an aberration that varies as the cube of the pupil causing a change in magnification for different zones of the pupil. It has a distinct form as shown in this spot diagram ( http://www.scopecraft.com/Technical%20Discussions/Coma%20Correction_files/Coma%20Correction_files/image001.jpg ) and the ends of the comatic tail fade and blur ( http://www.bma2.org/Constellation/img/2_01_5.jpg is the closest online image I could find ... in this star test image the coma is convoluted with the Airy diffraction pattern. I couldn't find a good image of large scale coma. )
I must ask if you are a pro photographer. I've been photographing for 20 years and, yes, at times I get odd things when light is at a certain angle. But everytime, it's an in camera problem and not something supernatural.
My profession for 25 years has been lens design, optical systems analysis, assembling and troubleshooting spaceflight optical systems (where you tend to deal with imaging dim objects with very bright sources just out of the field).

I treat skepticism with skepticism. I'll gladly adopt the Million Dollar Challenge mentality. Demonstrate a counterexample. Show me a single example of an image on which there's a comparable artifact (some similarity in size, sharpness, symmetry, orientation with respect to the center of the lens) whose source you've tracked to something on or in the lens and I'll be happy to concede. Or at least continue the discussion of causes.

[bignickel]

"(Conventional explanation) is impossible! Therefore, it could only be (Extraordinary explanation that has never happened before in the history of mankind)!"

[Miss Whiplash]

We disagree. I contend that this artifact, ( http://img.metro.co.uk/i/pix/2008/02/UFOCloseSOLENT_450x300.jpg ) approximately 1/40 the extent of the larger image shown has relatively sharp edges -- sharper than would be caused by aberration or lens flare.

Coma isn't simply "shapes caused by the curvature of the lens." It's an aberration that varies as the cube of the pupil causing a change in magnification for different zones of the pupil. It has a distinct form as shown in this spot diagram ( http://www.scopecraft.com/Technical%20Discussions/Coma%20Correction_files/Coma%20Correction_files/image001.jpg ) and the ends of the comatic tail fade and blur ( http://www.bma2.org/Constellation/img/2_01_5.jpg is the closest online image I could find ... in this star test image the coma is convoluted with the Airy diffraction pattern. I couldn't find a good image of large scale coma. )

My profession for 25 years has been lens design, optical systems analysis, assembling and troubleshooting spaceflight optical systems (where you tend to deal with imaging dim objects with very bright sources just out of the field).

I treat skepticism with skepticism. I'll gladly adopt the Million Dollar Challenge mentality. Demonstrate a counterexample. Show me a single example of an image on which there's a comparable artifact (some similarity in size, sharpness, symmetry, orientation with respect to the center of the lens) whose source you've tracked to something on or in the lens and I'll be happy to concede. Or at least continue the discussion of causes.

Ok, I concede. The Beans are right. That is an interdimensional space creature called a Shield. My only regret is I could have spun tales about those bad snaps I tossed out all those years and made a bundle.

Edit: Before we can replicate this photo, first we must have the camera. What was it? A D-SLR? A pocket digital? A frame from a video? What was the ISO? What was the shutter speed? What was the aperture? Of course if we replicate it and the thingie is red, that's a Red Guy (http://www.orbsbybeans.com/redguy.html).

[wahrheit]

Edit: Before we can replicate this photo, first we must have the camera. What was it? A D-SLR? A pocket digital? A frame from a video?

Look here and scroll down:
http://www.thesun.co.uk/sol/homepage/news/article793327.ece

Looks like a fancy DSLR with the usual zoom lens to me.

[Timothy]

"(Conventional explanation) is impossible! Therefore, it could only be (Extraordinary explanation that has never happened before in the history of mankind)!"

Ok, I concede. The Beans are right. That is an interdimensional space creature called a Shield. My only regret is I could have spun tales about those bad snaps I tossed out all those years and made a bundle.


The sarcastic tones seem to point to a gross misunderstanding of my argument.

Randi discussed in detail a certain type of lens flare, linked to photos of it, and described how you could with certainty tell which light source was responsible for the artifact in the image by tracing a (mostly) horizontal line.

I point out the discrepancies in that argument, and reasons why I believe it is not that type of lens flare, nor dust or smudgies on the lens, nor a Photoshopped alteration. At no time whatsoever have I said I believe it is an actual object of any kind, much less the fantasy story the photographer has concocted.

I fully believe it to be an optical phenomenon caused during the taking of the photo. But I am equally skeptical of "rational" explanations that do not appear to fit the observations, and none of the suggested solutions yet have the aura of truth. I'd like to find an explanation that fits all the available data and not be lazy and just toss in the dogmatic "dust on the lens" or "it's obviously fake."

[baron]

Sorry if I'm repeating anything (haven't read all the thread) but if I'd be hard pressed to point to an image that typifies lens flare more than this one does.

Invasion! http://www.darkstar1.co.uk/plymouthlensflares.jpg

[Timothy]

Sorry if I'm repeating anything (haven't read all the thread) but if I'd be hard pressed to point to an image that typifies lens flare more than this one does.

Invasion! http://www.darkstar1.co.uk/plymouthlensflares.jpg

Spectacular example! Although the terminology is by no means standard, most people would not refer to these as lens flares. It is a secondary reflection of the entire scene (the spacing and orientation of the sources is the same, not flipped about the origin) with aberrations on each of the sources. The aberrations don't strictly conform to coma, but you'll notice that a line drawn through the axis of symmetry of each artifact converge on a point near the top of the image. I would *really* like to know if this is the full image, or whether it's cropped (and the point of convergence is the center of the original image.)

Any provenance or background on the photo or the photographer?

[LTC8K6]

Looks sort of like the effect you can get when a camera is in a housing or there is a filter on the lens and there is a reflection off the housing glass or the filter.

At any rate, the original pic is clearly the same effect and not any sort of alien craft.

[baron]

Any provenance or background on the photo or the photographer?

You mean for the image I linked to? I know the person by screen name on another forum and I can PM you a link but you'll need to register so you can contact them. Let me know if this is what you meant.

[Miss Whiplash]

Look here and scroll down:
http://www.thesun.co.uk/sol/homepage/news/article793327.ece

Looks like a fancy DSLR with the usual zoom lens to me.

Thanks! I can't make out the brand name. Looks like a standard "pro-sumer" digital with the usual zoom as you mentioned.

[Father Dagon]

They don't. Americans do.They do. "Atumnumm" instead of "fall". The pronunciation is even worse: "c-ah" instead of "car", "colu-oh" instead of "color" and "huymorous" instead of "humor".

[korenyx]

When I looked at it again it reminded me of an effect of taking a flash photo into a mirror. When I did this (with instant film, a long time ago)
I got a picture of the flash and part of the mirror but there was also a large white star-shaped mark on the photo. This "UFO" photo looks similar; it's as if not all of the information from the picture made it to the film.

[NobbyNobbs]

That has got to be one tiny UFO hovering over Portsmouth.

"For thousands more years the mighty ships tore across the empty wastes of space and finally dived screaming on to the first planet they came across - which happened to be the Earth - where due to a terrible miscalculation of scale the entire battle fleet was accidentally swallowed by a small dog."

--Douglas Adams
"The Hitch Hiker's Guide to the Galaxy"

[baron]

The pronunciation is even worse: "c-ah" instead of "car"

I guess you've not visited Maine then.

[Father Dagon]

I guess you've not visited Maine then.Nope.

And BTW, I would like to learn african french, beacuse the pronunciation is nicer.

[bignickel]

The sarcastic tones seem to point to a gross misunderstanding of my argument.
If I have been overhasty in my characterization, I do apologize.

I and many others have seen way too many people come to the places like the Conspiracy sub-forums, state "I have a few questions", and within 10 posts go into full "You are all a bunch of sheeple! Thermite! Faster than freefall!" mode. It gets a bit old.

[Minkster]

No, we just moved on from the seventeenth century

Actually, not 100% correct. If anything, its the other way around.

Shamelessly stolen from another forum I am on :

"I yield to no-one in my dislike of Americanisms (not content with being unable to pronounce the word "leverage" properly, they go on to insist it's really a verb - "to leverage something"..... I could go on), .... but the '..ize' vs '..ise' thing is not an Americanism. <geek> ..ize was once pretty much universal - not least when America split from the mother tongue. We're the ones who have moved on in that instance. The whole "harbor" / "harbour" debate is much the same; you won't find many, say, Elizabethan texts that (un-edited) spell it any way other than the American one. They also still use some old-fashioned words that have long since passed out of everyday English; anyone ever seen the word "apparel" (meaning clothes) used in a text that's under 200 years old on this side of the pond? They use it fairly routinely."