Blue ring around moon

[kbreit]

I was taking your fairly standard picture of the moon tonight and was noticing that at larger apatures, the moon had a blue ring around it. What causes this?

[FlyingPete]

I was taking your fairly standard picture of the moon tonight and was noticing that at larger apatures, the moon had a blue ring around it. What causes this?

That would be the new atmosphere that is secretly being made up there :D

Really though sounds like 'Purple Fringing' (I think the technical term is Chromic Aberration) which is often seen a wider apertures in high contrast areas. Lower quality lenses seem to be particularly prone to this.

It wouldn't have happened to be your 28-200 that this was happening on? Those lenses have awesome zoom, but make many design compromises to get there.

[kb244]

The thin halo you sometimes see around the moon is actually ice crystals refracting the light bounced off the moon. Most of the crystals refract the light at a 22degree angle ( thus 22° halo ).

More information here : http://www.gsfc.nasa.gov/scienceques2002/20030124.htm

[kb244]

Btw talking bout imperfections of lens.

if anything, canon should be correcting our atmosphere to give us cleaner pictures, maybe put a DO (Diffractive Optics) dome up there

[kbreit]

That would be the new atmosphere that is secretly being made up there :D

Really though sounds like 'Purple Fringing' (I think the technical term is Chromic Aberration) which is often seen a wider apertures in high contrast areas. Lower quality lenses seem to be particularly prone to this.

It wouldn't have happened to be your 28-200 that this was happening on? Those lenses have awesome zoom, but make many design compromises to get there.

Yeah it was the 28-200 that I was using. To be honest, it's either that for me or the kit lens that comes with the 350D.

[FlyingPete]

The thin halo you sometimes see around the moon is actually ice crystals refracting the light bounced off the moon. Most of the crystals refract the light at a 22degree angle ( thus 22° halo ).

More information here : http://www.gsfc.nasa.gov/scienceques2002/20030124.htm

I would think you would see that at all apertures? I nearly always get it to some degree through my telescope when taking photos, I put that down to moisture in the atmosphere.

[kb244]

I would think you would see that at all apertures? I nearly always get it to some degree through my telescope when taking photos, I put that down to moisture in the atmosphere.

Not with the kind of lens you normally put on a camera further more filters that typically block out IR light, and chromatic abberations and such. Telescopes and such usally let in all possible kind of light in, where as more lens they have coast of this and that to help against stray light to make the image "cleaner"