[LargeFormat] Elgeet Update

[Les Newcomer]

On Tuesday, March 4, 2003, at 02:31 AM, Clive Warren wrote:

> Alan,
>
> Richard may have mentioned this earlier, but in1962 the Elgeet 'firm=20=

> acquired ownership of the ancient establishment of Steinheil in =
Munich'=20
> (from Kingslake).

> The only mention of large format lenses I can find is the Elgeet=20
> Anastigmat f4.5 250mm which is of course your lens. Be wary that the=20=

> circle of illumination is probably larger than the useful image =
circle.
>
> Cheers,
>            Clive
>
>

Looking up Steinheil in  my '39 ed of "Handbook of Photography"  I find=20=

they made a 250mm f4.5 Unofocal lens.  This was similar to the Celor and=20=

Aviar, and later the Artar.  It has 4 symetrical air spaced elements  =
with=20
an angle of view of 60=B0, and is the basis of most process lenses.

If we let a=3D the radius of the coverage angle, then 2a=3D 2[focal =
length x=20
Tan (half the angle of view)]  will give us the circle of coverage.  =
Thus

2a=3D2(10 x Tan 30=B0)

2a=3D 2 x 5.7735"

2a=3D11.54"