Re: OFF TOPIC QUICKIE

----- Original Message -----
From: "Bob Kiss" <bobkiss@caribsurf.com>
To: "ALT PHO PROC." <alt-photo-process-l@usask.ca>
Sent: Thursday, January 20, 2005 7:38 AM
Subject: OFF TOPIC QUICKIE

> DEAR LIST,
> I am about to buy a 300 mm enlarging lens for my 8X10
> enlarger. I just
> want to confirm my belief that a 300 mm lens will
> completely cover an 8X10
> negative without vignetting. Am I right?
> CHEERS FROM BARBADOS!
> BOB
>
> Please check my website: www.bobkiss.com
>
   Nearly any 300mm LF or process lens will cover 8x10 for
enlarging. Remember that the angle of coverage is ususally
given for infintity focus and that field of the lens becomes
larger for closer distances; at 1:1 the field is double the
diameter it is at infinity. At the sort of low magnification
likely to be used for 8x10 even narrow coverage process
lenses, like the Artar, will cover with ease. Modern
"Plasmat" type enlarging and process lenses generally have
greater coverage than the older four element type process
lenses.
   Before specialized enlarging lenses became available the
standard lens for high quality LF color work was the Goerz
Apochromatic Artar process lens.

---
Richard Knoppow
Los Angeles, CA, USA
dickburk@ix.netcom.com