---
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED]]On Behalf Of Rodger Whitlock
Sent: Tuesday, November 27, 2001 11:55 AM
To: [EMAIL PROTECTED]
Subject: Re: APO Lenses
On Mon, 26 Nov 2001 at 19:12:30 -0500, "Isaac Crawford"
<[EMAIL PROTECTED]> wrote:
> You mean down to the
On Mon, 26 Nov 2001 at 19:12:30 -0500, "Isaac Crawford"
<[EMAIL PROTECTED]> wrote:
> You mean down to the photon!? Who's BSing now? We aren't
> talking about a machine shop, we're talking about light. It is
> literally impossible to grind lenses to within a photon's breadth
> of correction.
D]
[mailto:[EMAIL PROTECTED]]On Behalf Of Tom Rittenhouse
Sent: Friday, November 23, 2001 4:55 PM
To: [EMAIL PROTECTED]
Subject: Re: APO Lenses (was Re: Layers, Sharp Focus, and New-Fangled
Color Film)
Yes, but. Whether that common focus is within a tenth of an inch, a
hundredth of an inch, or a
Gittings
-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED]]On Behalf Of Rob Brigham
Sent: Thursday, November 22, 2001 6:39 AM
To: [EMAIL PROTECTED]
Subject: RE: APO Lenses (was Re: Layers, Sharp Focus, and
New-FangledColor Film)
I think you are confusing this with
EMAIL PROTECTED]]On Behalf Of Martin Trucco
Sent: Wednesday, November 21, 2001 8:01 PM
To: [EMAIL PROTECTED]
Subject: Re: APO Lenses.
>Now this I'd like to hear more about. Can you elaborate on this point,
specifically, how do manufacturers get away with labeling a lens as
Apochromatic
- Original Message -
From: Shel Belinkoff <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Wednesday, November 21, 2001 12:57 PM
Subject: APO Lenses (was Re: Layers, Sharp Focus, and New-Fangled Color
Film)
> Now this I'd like to hear more about. Can you elaborate on this point,
> spec
Lon wrote:
> Maybe not. As I understand it, APO elements, like any other element,
> may be a) plastic, b) molded glass, or c) ground glass, with cost
> escalating from a (cheapest) to c (pricey).
No, you're confusing apochromatic with aspherics, which are made in the
types you ennumerate above
Rob Brigham wrote:
>
> I think you are confusing this with 'Aspherical' - shape of lenses to
> correct aberrations.
> The Sigma APO refers to a lens coating rather than lens design.
You're probably right about the aspherical, but Sigma identifies
the number of APO elements in their lenses, so I'
I suspect that they only approach perfection, as a goal, but never actually
achieve it. The real world does have to be considered, ya know what I mean?
In other words, when you get close enough, you can claim victory.
To hold them to having to be perfect because they use the term APO is not
reali
9 matches
Mail list logo
