Re: Horseman SW 612

["Mitchell P. Warner" <indepth@xxxxxxxxxxxxxxxx>]

Ellis:   You are, of course, correct about the difference between angle of
view and the Coverage, or lens circle.  The following is from the B&H page:

http://www.bhphotovideo.com/photo/large/lenses/lensintro.html#lens

Angle of Coverage

This is a measure of the entire image circle of the lens. Do not confuse
this with the angle of view. The angle of coverage simply refers to the
image-forming cone of a lens. This tends to be similar for a number of
different focal lengths that are made from the same basic lens design.
Take, for example, the Schneider Super Angulon series. Almost every lens in
this group has an angle of coverage of either 100° or 105° and focal
lengths ranging from 65mm to 210mm. All of these lenses are considered
wide-angle, and each focal length is designed for a specific format. The
65mm lens is intended for use with 4x5" film; the 210mm lens, with 8x10"
film. These lens-and-film format combinations provide wide angles of view
of approximately 86° and 61°, respectively.

As mentioned earlier, the image circle refers to the area that produces
sharp images. Once again, the size of the image circle is determined by the
specific lens design. Furthermore, each film format has its own minimum
requirement for coverage. For example, 4x5" film needs 161mm, and,
fittingly enough, 8x10" calls for twice as much, or 323mm. But these are
just minimal figures, required when the lens axis is aligned with the
center of the film, as with 35mm and medium-format cameras.



Further, you said: 

	"I believe Mitchell may have inadvertently made a mistake
>when he was typing up the specs."

	NOT.   The specs were cut and paste directly from 

http://www.bhphotovideo.com/photo/large/lenses/navigation.html

The 45mm ApoGrandagon 

specifications of RODENSTOCK GRANDAGON N series lenses 
                Lens 				45mm 
Aperture Range 				4.5-32
Shutter Type 					Copal 0 
Maximum Recommended Film Format (In.) 	4x5"
Angle of Coverage at f/22: 			110° 
Image Circle at f/22: 				131mm 
Filter Size Ø 					58mm 


And here the spec's for the SCHNEIDERSuper Angulon 47XL

specifications of SCHENIDER SUPER ANGULON XL lenses 
Lens 						47mm 
Aperture Range 				f/ 5.6-32 
Shutter Type 					Copal 0
Maximum Recommended Film Format (In.) 	4x5" 
Angle of Coverage at f/22: 			120°
Image Circle at f/22: 				166mm 
Filter Size Ø 					67mm 


I have NOT had the opportunity to work with any of the APO--Grandagon
lenses  or the Schenider SA 47XL in large format configurations so "I"
cannot comment on them from first hand, subjective,  experience.  
The tables above are Technical, objective,  Specifications from the
manufacturers, not an analysis of light transmission or esthetic
performance.  Lenses vary in their performance, just as cars do.
Individual, anecdotal claims aside, the spec's speak for themselves. 

>From the Schenider page: 

http://www.schneideroptics.com/large/super_angulon/xl47/daten.html



Super-Angulon XL 5.6/47mm
120° 
 

OPTO-MECHANICAL DATA
Filter Thread (front) M 67 X 0.75 
Front Outer Diameter 70mm 
Rear Outer Diameter 63.5mm 
Shutter Size # 0 
Minimum Aperture (Copal) 32 
Flange Focal Distance (Copal) 59.1mm 
Mounting Thread (Copal) M 32.5 X 0.5 
Weight (with Copal shutter) 310 grams 
Overall Length 60.8mm 

IMAGE DATA
(with lens focused at infinity)
Recommended Format (negative) Size 4 X 5 inches 
Image Circle Diameter at f/5.6 110mm 
Image Circle Diameter at f/22 166mm 
ANGLE OF VIEW at f/22 120 degrees 
Lens Displacement at f/22 (vertical/horizontal) 9/8mm 

>From Rodenstock page:

http://www.rodenstockoptics.com/viewcam_index.htm

Whenever small rooms, wide spaces or short taking distances (architecture)
make large field angles necessary, the lenses of first choice are the
Apo-Grandagon and the Grandagon-N with field angles of up to 110º. 

 
Lens: APO-GRANDAGON 

45mm f/4.5  

Image circle Ø at 1:¥ and f/22     131mm  

Max. recommended film size6 x 9cm/  6 x 12cm 

Shutters (smallest aperture) f32   

IE: 
Rodenstock Apo Grandgon 45mm f 4.5.  
Image circle at f/22     		131mm  
Angle of view:			110º


Schnider Super-Angulon XL 5.6/47mm
Image Circle at f/22 		166mm 
Angle of vies: 			120 degrees 

 



At Your Service, 


mitch warner