[LargeFormat] Kodak 7 1/2" Ektar Coverage?

[Clive Warren]

At 7:58 am -0800 5/1/01, Les Newcomer wrote:
>The only 190 I show in my 1954 booklet is the Wide Field Ektar.
>Kodak says it covers 8x10 without swings and has an angle of view of 56=B0x=
68=B0*
>*At maxiumum aperture, for larest recommended neg size, no swings.
>(I've never been able to define their use of "maximum" here, wide open
>or stopped down?)
>
>filter size is 63mm or Series VIII. These should drop in the front and
>held in with a series VIII shade or filter ring, no press-on adapter needed=
=2E
>
>From the 40s through the early 60s, the date of manufacture can be
>decoded by using the two letter part of the serial and the following rule
>
>
>C A M E R O S I T Y
>1 2 3 4 5 6 7 8 9 0
>
>  Thus an RO serial number was made in '56
>
>I use mine on my 8x10 with great results. Best to use it at f16 or greater.
>
>Les
>
>Clive Warren wrote:
>>
>>  Just picked up a 7 1/2" Ektar in the continuing search for a standard le=
ns
>  > for my 5x7 field outfit. The glass has cleaned up well and the shutter =
has
snip

Thanks for the information Les. The lens is not a 190 WF Ektar, 
rather it is the 7 1/2" Ektar f4.5 dating from 1948. Why didn't other 
manufacturers use a similar dating method for their lens serial 
numbers? Makes life a lot easier :-) The 7 1/2" lens has the usual 
luminized coating of the Ektars and is mounted in an Ilex #4 shutter. 
This makes the lens rather heavy as it also has fairly large elements 
to give the large aperture of f4.5. Focussing should however be an 
easy process :-)

The 190mm WF Ektar has a lot more coverage but probably is not as 
sharp in the edges as a "normal" coverage lens. The 190mm also tends 
to be rather expensive and is probably overkill for a 5x7 outfit. 
=46rom the large format lens specification table on the f32 web site 
the 190mm WF Ektar has an image circle of 318mm:

http://www.f32.net/Services/Equipment/Lenses/lensspecs.html0


I am interested in finding out the image circle of the 7 1/2" f 4.5 
lens. Working out the circle of illumination is relatively easy by 
inspection.
-- 
All the best,

             Clive Warren   http://www.f32.net
                            Large Format travel and stock photography