[LargeFormat] Keep the list alive! - Off Topic - 6x6cm

[Jim Hemenway]

Hi Richard:

Thanks, that's what I wanted to know.

Does spherical aberration manifest itself in the corners/edges as well?

Jim - http://www.hemenway.com



Richard Knoppow wrote:

> 
> -----Original Message-----
> From: Jim Hemenway <Jim@Hemenway.com>
> Sent: May 6, 2004 1:51 PM
> To: largeformat@f32.net
> Subject: [LargeFormat] Keep the list alive! - Off Topic  - 6x6cm
> 
> Hi Folks:
> 
> Some of you folks know a lot about optics, so I'm wondering if anyone 
> can tell me if chromatic aberration is the name for the green and red 
> stripes on the sides of the lighthouse in the first picture in the set 
> below.  Look for the blow-up under the Boston Harbor photo on the left 
> side of the pair.
> 
> If it is chromatic aberration, why does it show up one one fisheye lens 
> and not the other?  Is there a missing element?
> 
> These are some side-by-side fisheye photos taken with the Arsat 30mm on 
> a Kiev 60, and the Zeiss F-Distagon 30mm on a Rollei 6008i.
> 
> When you click on any of them you'll be presented with large photos. If 
> you press your right mouse button, (in Netscape 7.1) and choose view 
> image, the photo(s) will be reduced in size to fit your screen. I think 
> that something similar is available in IE.
> 
> Astia 100
> 
> Most at f8 - f16
> 
> No sharpening
> 
> No PS work except for spotting.
> 
> http://www.hemenway.com/ArsatDistagon
> 
> Thanks,
> 
> Jim Hemenway
> 
> 
>    I am assuming that you can see the same thing on the film. If so, its chromatic. 
>     Chromatic aberration takes two forms: one is lateral, one longitudinal. Longitudinal is the kind most of us are familar with; its the reason a magnifying glass shows color fringes. The focal length of the lens varies with the color so different colors come to focus at different distances from the lens. Lateral color is also known as chromatic difference of magnification. Lateral color can exist in lenses which are corrected for longitudinal chromatic aberration. It produces images which all focus at the same distance but where the size varies with the color. There are other aberrations which can vary with color, for instance spherical aberration. These can also produce color fringes but they may vary in different ways from simple chromatic aberration. 
> 
> 
> 
> Richard Knoppow
> dickburk@ix.netcom.com
> Los Angeles, CA, USA