[LargeFormat] Double Protar Lens

[LNphoto]

On Sunday, August 31, 2003, at 01:19  PM, Clive Warren wrote:

> Have just picked up a Bausch and Lomb Series VII Protar for a 5x7 
> camera that appears to be a double convertible rather than a triple. 
> Without looking at the books, I thought they were all triple 
> convertibles. Does anyone have one or used one?
>
> Cheers,
>            Clive
>
>
>
>
If you bought to cells of different focal lengths you gained a third 
focal length at the cost of speed as most combined were either f 7.0 or 
7.7.   If you combined two of the same lenght your combined focal 
length was f6.3....modestly fast for those days.