Show your shots - Photography

[Hennie]

I'm in Pretoria unfortunately, but I'll look a few Wikipedia links up and post them. They are better at explanations that I am...

[Hennie]

Chromatic aberration:

http://en.wikipedia.org/wiki/Chromatic_Abberation
http://images.google.co.za/images?um=1&hl=en&q=chromatic+aberration&btnG=Search+Images

Achromatic lens:

http://en.wikipedia.org/wiki/Achromat

An achromatic lens usually brings red and blue in focus, but leaves green uncorrected. That's why achromats still give green fringes (and other colours like purple to a lesser extent) on high contrast transitions. This is what made me think that the green fringes on your photo are caused  by chromatic aberration.

Apochromatic lens:

http://en.wikipedia.org/wiki/Apochromat

Corrects for three primary colours and as a consequence overall uncorrected errors are significantly reduced. Green fringes would be absent.

Coma aberration:

http://en.wikipedia.org/wiki/Coma_(optics)
http://images.google.co.za/images?hl=en&q=Coma%20Aberration&um=1&ie=UTF-8&sa=N&tab=wi

Lens flare:

http://en.wikipedia.org/wiki/Lens_flare
http://images.google.co.za/images?um=1&hl=en&q=lens+flare&btnG=Search+Images

Lens flare is seldom green. It usually shows the colour of your lens coating.

Most lens aberrations are reduced by smaller apertures, making the lens sharper. But there's a trade-off, as a smaller aperture increases diffraction which also reduces sharpness. In practice most achromats are sharpest at around f5.6 to f8, or if it is a slow zoom, 2 - 3 full stops down. When you stop down, sharpness increases due to a reduction in aberrations, then somewhere in the middle the lens reaches max sharpness before sharpness starts to degrade due to diffraction. Apochromats are sharpest closer to max aperture, perhaps a stop down from max aperture.

BTW nice pics.

[abrie]

Gatskop

do you go to Namibia quite often - when did you take the pic of dune7?

[Gatskop]

Gatskop

do you go to Namibia quite often - when did you take the pic of dune7?

Every second December. My wifes parents stay in Oshakati, but Decembers they go to the sea and desert.
This year we are going to Torrabay, nice fishing!

[abrie]

daai is my wereld. I was born in Walvisbaai and have familly in Walvis and Swakopmund.

so I just had to ask. 

[Hein]

AG NEE K@K!!!

I was going to post some (what I thought were) pretty pics...

You guys are just TOO intimidating!!! 

[Willi]

kom nou hein, wys ons.

[Dolby]

Um. I dunno how to delete ...

[Dolby]

Anyway

I know this old, but thought I'd post a few as well.


Watershed by Dolby2000, on Flickr


Prime Circle by Dolby2000, on Flickr


Farryl Purkiss by Dolby2000, on Flickr


Arno Carstens and Albert Frost by Dolby2000, on Flickr

[mahleu]

Some of mine...

[guido]

[guido]

[guido]

[kamikazi]

[kamikazi]