[LargeFormat] Double checking.

[Les Newcomer]

> From: "philip.lambert" <philip.lambert@ntlworld.com>
> Reply-To: largeformat@f32.net
> Date: Tue, 19 Mar 2002 07:24:48 -0000
> To: <largeformat@f32.net>
> Subject: Re: [LargeFormat] Double checking.
> 
> 
> ----- Original Message -----
> From: "Les Newcomer" <lnphoto@twmi.rr.com>
> 
> 
>> A common focal lenght for diffused focus is 14-15" for 6x8 (tho they
> usually
>> cover 8x10) and 16-18" for 8x10.  An 18" f4.5 lens is a damn heavy piece
> of
>> glass, which is why portrait cameras were built with mimimal movements and
>> maximum strenght in the front end.  If seen an 18" f 2.8 lens.  it's the
>> size of a small waste basket and pretty much destroys any camera it's on.
>> 
> I'm always impressed by your contributions.  You clearly lead an interesting
> if muscular photographic life.
> Could one attach a minus lens to a standard lens and thus extend the focal
> length and soften the image, assuming the added minus glass brought some
> abberations with it? Philip
> 
ABSOLUTELY!!!   Thus the 10"  and 15" tele-optar of Speed Graphic fame, the
Adon lens, and the earlier tele-attachments. Although not only does the
latter suffer from distortion (barrel and pincushion) the light lost in
spreading the image negates any advantage is softening.

It's always fun to tell somebody that in order to 'magnify' the image of a
lens you need a negative element, then I watch their face as their brain
wraps around the concept, of "yeah, image spread out, keep the format, thus
larger magnification, But only positive lenses magnify! neg lenses make
things smaller I've seen it with my own eyes!!

It's a lot of fun to watch their hair curl and smoke come out their ears!