[LargeFormat] Some simple lens coverage tests with paper negatives

[Les Newcomer]

On Saturday, March 22, 2003, at 10:32  PM, Richard Knoppow wrote:

>
> ----- Original Message -----
> From: "Jim Hemenway" <Jim@hemenway.com>
> To: "Large Format Group" <largeformat@f32.net>
> Sent: Saturday, March 22, 2003 6:39 PM
> Subject: [LargeFormat] Some simple lens coverage tests with
> paper negatives
>
>
>>>
>> The 23 1/4 Protar used with both cells focuses at about
> 340mm.
>>
>> The Protarlinse which came with my 8x10 and which focuses
> at about 310mm
>> with both cells, vignettes. I didn't test it with the 41cm
> or 59cm
>> cells.
>>
>> http://www.hemenway.com/lens_coverage
>>
>> --
>>
>> Jim - http://www.hemenway.com
>>
>   I am curios about the 23-1/4 Protar, is this the marked
> focal length of each cell? I can not find this focal length
> listed as either a Zeiss or Bausch & Lomb lens.
>   <snip>
>   Bausch & Lomb; 23-1/8" Combined FL for two identical
> cells; 13-1/4, f/6.3
>   B&L states coverage at full aperture is sufficient for an
> 8x10 plate.
>   ---
> Richard Knoppow
> Los Angeles, CA, USA

I have an undated B&L "Anastigmatics"  catalog that  That shows (as you 
said) a No. 19  covering 8x10 as a pair of 23 1/8"  However I also have 
a 1914 B&L Lens catalog shows the same number 19 as being 23 1/4" and 
covers 12 x 16 at smaller stops.  It cost 179.00 in a Compound shutter 
the same year Henry Ford doubled the factory worker's wage to $5.00 a 
day