strange optical effect

Can someone, please, explain how this strange effect was achieved: I
saw it in the videoclip
"Air Rings" (at rent-a-cloud.com). It is a large illuminated ring which
changes shape as the sun moves down. It doesn't look like done via
filter, and I can't think of any lens that could do it. I emailed their
site, but their cameraman is not available at present.
Grateful for answer.

xelob wrote:
Can someone, please, explain how this strange effect was achieved: I
saw it in the videoclip
"Air Rings" (at rent-a-cloud.com). It is a large illuminated ring which
changes shape as the sun moves down. It doesn't look like done via
filter, and I can't think of any lens that could do it. I emailed their
site, but their cameraman is not available at present.
Grateful for answer.

I dont know the answer but it sure looks like the focal length is
changing.

A long video for such a minor effect.

On 27 Sep 2006 21:25:44 -0700, "xelob" wrote:

It is a large illuminated ring which
changes shape as the sun moves down.

It looks like a reflection onto a curved lens surface. I think the
size changes because the sun is getting closer to the center of the
FOV.

Cheers,
DuncanC

In article , Duncan Chesley wrote:
On 27 Sep 2006 21:25:44 -0700, "xelob" wrote:

It is a large illuminated ring which
changes shape as the sun moves down.

It looks like a reflection onto a curved lens surface. I think the
size changes because the sun is getting closer to the center of the
FOV.

I can't see the video, it does not work. Video lenses are typically cheaper
than camera lens and not coated as well, if thats the problem or effect.

greg

xelob wrote:
Can someone, please, explain how this strange effect was achieved: I
saw it in the videoclip
"Air Rings" (at rent-a-cloud.com). It is a large illuminated ring which
changes shape as the sun moves down. It doesn't look like done via
filter, and I can't think of any lens that could do it. I emailed their
site, but their cameraman is not available at present.
Grateful for answer.

Part of the image looks like a sun dog
(http://en.wikipedia.org/wiki/Sun_dog). I've never seen a
circular sun dog, but it may be a related effect. Circular
rainbows aresometimes seen, but there is no color dispersion
in that image.

Duncan Chesley wrote:
On 27 Sep 2006 21:25:44 -0700, "xelob" wrote:

It is a large illuminated ring which
changes shape as the sun moves down.

It looks like a reflection onto a curved lens surface. I think the
size changes because the sun is getting closer to the center of the
FOV.

Cheers,
DuncanC

Thanks for your reply. You could be right
Cheers

Marvin wrote:
xelob wrote:
Can someone, please, explain how this strange effect was achieved: I
saw it in the videoclip
"Air Rings" (at rent-a-cloud.com). It is a large illuminated ring which
changes shape as the sun moves down. It doesn't look like done via
filter, and I can't think of any lens that could do it. I emailed their
site, but their cameraman is not available at present.
Grateful for answer.

Part of the image looks like a sun dog
(http://en.wikipedia.org/wiki/Sun_dog). I've never seen a
circular sun dog, but it may be a related effect. Circular
rainbows aresometimes seen, but there is no color dispersion
in that image.

Many thanks for your reply.
Cheers -