[LargeFormat] Seneca 5x7

[Richard Knoppow]

At 07:00 PM 08/15/2002 -0700, you wrote:
>Hi Les!
>
>     And thanks for the suggestion about the extention box with the
>packard shutter.
>My first lens will probably be about 7 inch or 180mm.  I'll look for
>something older.
>I need to pull all this together soon.  Did Kodak make a 7 inch Ektar
>and would this
>cover 5x7 with some movements?
  There are no 7" Ektars. 
  There is a Wide Field Ektar of 7.5 inch focal length, f/6.3. This lens
has about an 85 degree coverage at small stops enough to cover 5x7 with
movements and 8x10 without movements.  
  The longest of the f/4.5 series Ektars was 152mm (actually, there was
also a 12", f/4.5 lens made for a short time) and the shortest Commercial
Ektar was 8-1/2 inches. The 8-1/2" lens covers 5x7 with some movement.
Commercial Ektars are capable of about 65 degree coverage.
  A better choice, especially where a shorter lens is required would be
something like a Schneider f/5.6 Symmar or a Dagor. The Symmar is capable
of around 80degree coverage, depending on the version, the Dagor of 87
degrees at f/45, though probably 80deg is more reallistic. Convertible
Protars have about 80 degree coverage, the greatest being when front and
rear cells are the same focal length. 
  The 203mm (8 inches), f/7.7 Ektar is a dialyte type with rather narrow
coverage. It was sold as an economy lens for 5x7 but is really more
suitable as a 4x5 lens. This type does not increase coverage significantly
as it is stopped down. 
----
Richard Knoppow
Los Angeles, CA, USA
dickburk@ix.netcom.com