[LargeFormat] a nice lens for 11x14

[Richard Knoppow]

----- Original Message ----- 
From: "philip lambert" <philip.lambert@ntlworld.com>
To: <largeformat@f32.net>
Sent: Tuesday, January 20, 2004 7:48 AM
Subject: Re: [LargeFormat] a nice lens for 11x14


> Is it a practical alternative to take several photos with
a more
> realistically priced wide angle lens and stitch them
together digitally?  PL
> ----- Original Message ----- 
> From: "LNPhoto" <LNPhoto@twmi.rr.com>
> To: "f32" <largeformat@f32.net>
> Sent: Tuesday, January 20, 2004 4:23 AM
> Subject: [LargeFormat] a nice lens for 11x14
>
>
> > I thought this might interest Jim Hemenway
> >
> >
http://www.cliveruss.com/classiclns/hypergon150/hypergon.html
> >
>
  The Hypergon is a very interesting lens. Despite its
simplicity, just two elements, it covers 140 degrees. Since
it is not corrected for spherical aberration it must be used
at very small stops, around f/45. There is a propeller
shaped stop in the front for equalizing the edge fall off.
This equalizer is operated by air and is in place for about
the first half of the exposure falling away for the second
half.
  While one can make a panoramic picture of even greater
coverage it isn't quite the same as the extreme wide angle
effect of this lens.
  The well known Zeiss Topogon and Bausch & Lomb Metrogon
wide angle aerial mapping lenses are derived from this lens
although they are also double Gauss lenses. The Hypergon was
invented by Emil von Hoegh, the inventor of the Dagor.
  As far as cost, Hypergons are fairly rare and are as much
collector's items as usable lenses. I suspect the equalizing
device is missing from a lot of them.

---
Richard Knoppow
Los Angeles, CA, USA
dickburk@ix.netcom.com