what the hell is it ??, and how do i avoid it ..

[rowdy23]

hello again.
below is a pan i stitched of the gallery in melbourne library.
i noticed that it has what i think is called banding around the centre 3rd of the image.
just want to know what it is and how to avoid in the future .
http://i55.tinypic.com/2z5uetw.jpg


any help would be great.
exif is-
f4.5
iso200 ( i wanted to make the light illuminate rather than camera settings )
taken at 18mm
at 1/50th
canon 550d
18-135mm lens

regards
josh

[Adrian Fischer]

Do you mean on the floor?

[rowdy23]

hi adrian....
i mean the ghosting in the top half of centre 3rd.
it actually looks like some weird reflection of the floor...

not sure how that could be.

[OzzieTraveller]

G'day josh

When I enlarge my screen image to about 300% I can now see what you're referring to - at about the 11 o'clock to 2 o'clock position to the central white bit

It is a plain ole case of "light refraction" ... every lens will respond to an extremely bright -but small- light source, esp where that light source is off-centre to the direction of the lens itself
As I see it, your lens has picked up the very bright reflections from the floor and has "hazed" them diagonally across the internals of the lens to become visible on the other side of the image ~ all pretty normal for a lens

What to do about it?
In this context - maybe not much, tho a pro 'tog in a commissioned job would arrange for the doors to the other room to be closed to prevent it occuring

Hope this helps a bit ...
Regards, Phil

[rowdy23]

gday ozzie...
that helps alot,
thanks heaps for your post, great info.

josh