Re: Re[2]: [ATM] over&under correction.

["Bob May" <bobmay@nethere.com>]

Richard, would you kindly use the correct scheme for posting a reply to the
list?  A "Re[2]" isn't a valid reply prefix to the subject line for a start.
This kicks you out of the threading system and makes it a lot more difficult
to follow what you are talking about.  Without following threading rules,
you are just saying things without anybody knowing where you are coming
from, thus the need of several here to have quotes from previous posts so
that they can understand something of what it is being discussed.
Next, you didn't use any quote character (the > character at the beginning
of each line) when doing your quote and thus it becomes a bit difficult to
understand where your comments start and stop and the other person's
comments exist.
My, aren't we getting into a royal pissing contest on this subject!  Let's
all vote to crawl back to where we came from on this and follow the rulse
for posting??
Bob May
bobmay@nethere.com
http://nav.to/bobmay
http://bobmay.astronomy.net
----- Original Message -----
From: Richard <cnc@cncservo.co.uk>
To: Scott Milligan <atm@atmlist.net>
Sent: Monday, July 11, 2005 10:01 AM
Subject: Re[2]: [ATM] over&under correction.


> Hi Scott,
>
> Monday, July 11, 2005, 5:41:38 PM, you wrote:
>
>
>
> SM> Not only is there no difference in summary quality measures, the in
focus
> SM> diffraction patterns are exactly the same. Also, the extrafocal
diffraction
> SM> pattern in one case exactly matches the infrafocal diffraction pattern
in
> SM> the other for the same amount of focus travel. So, based solely on
optical
> SM> theory there's no difference at all between the two cases.
>
> SM> Of course I defer to others on which condition is easier to fix.
>
> SM> Mike Peck
>
>
> SM> Extending this discussion to ask the question "which is worse, a tenth
wave
> SM> edge rolled down or up" I would conclude that either of these defects,
> SM> occupying otherwise equal areas, position and magnitude on the mirror,
will
> SM> have the same impact on contrast transfer.  I make this observation
only
> SM> because over the years I have heard much commentary regarding the need
to
> SM> avoid even the slightest amount of turned edge, but relatively little
energy
> SM> spent warning against residual turned up edge.  In my (perhaps overly
> SM> simplistic understanding), a zonal error of slope Y and amplitude X
has the
> SM> same impact on MTF regardless of sign, even if for other reasons, one
is
> SM> more easily detected via the star test than the other.  Comments?
>
> SM> Scott Milligan
>
>
> SM> _________________
>
> SM> Michael Peck
> SM> email mpeck1@ix.netcom.com
> SM> Wildlife photoblog! http://wildlife-pix.com
> SM> Amateur telescope making
> SM> http://home.earthlink.net/~mlpeck54/astro/astro.html
>
> SM> _______________________________________________
> SM> ATM mailing list http://www.atmlist.net/
>
> SM> _______________________________________________
> SM> ATM mailing list http://www.atmlist.net/
>
>
> Scott, can you please use the normal > quote symbol when
> quoting. What with lack of quote marking and digest replies
> containing unmarked excerpts from several messages, many
> messages on this list are getting impossible to follow or place
> in thread. Sorry for quoting the whole message here but I
> thought it was needed.
>
> --
>
> Best regards,
>   Richard in the UK
>
>
>
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
>

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