Orion ha respondido a mi mensaje en el grupos yahoo de Orion Optics Uk en los siguientes términos, adjunto los mensajes del más antiguo al último:
Hello all:
This analysis has appeared in the principal forum of debate on
astronomic material of Spain:
http://www.asociacionhubble.org/portal/ ... /foro.html?
wrap=dmlld3RvcGljLnBocD90PTMxOTEy
It is a question of the analysis with Foulcaut of a mirror Orion
Optics UK 1/10 PV and Hilux.
Translation of the essential of the principal message, excuse my
english:
The image that offers the surface of its optics is that of the
lamentable polished one that has left almost the whole surface with a
painful appearance, which gives more impression of a carved(tooled)
field that what really should offer this mirror that would be an
exquisite delicacy. At all beyond(farther,further) of the reality, it
is the polished mediocre one that to caused what optically we call
(Mamelonage) and very severely. The examination with the mask of
couder does not deny that the parameters are correct, but this stays
in the second plane because the appearance of the polished one is
loaded any positive information of the optics. The differences caused
by the atrocious polished one will have to affect necessarily the
great yield supposedly granted to this mirror. As the only positive
information to say that at least the edge of the mirror is intact and
the most external zone is saved a bit from the aggressivness of the
polished one of the rest of the mirror.
Each one who extracts his own conclusions.
Regards
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From: Orion Optics
To:
oriontelescopes@yahoogroups.com Sent: Thursday, March 05, 2009 1:01 PM
Subject: [oriontelescopes] Re: Orion Optics UK 1/10 PV mirror analysis Foucault
Hello Group,
In response to the recent email below we investigated the complaint and replied to the friend of the gentleman. The Zygo report is here in the files section
http://groups.yahoo.com/group/oriontele ... servar.bmpBest Regards
Barry
Hi,
I have just looked at the mirror on our Zygo reports.
Here is the data
PV 0.099
RMS 0.016
Astigmatism 0.022
Strehl 99.0%
The Strehl shows you how 'lumpy' the mirror is. It is giving you a number which shows you what amount of error the mirror has overall, not PV which shows you just the highest and lowest error.
If you check with other suppliers of mirrors you will find the relationship of RMS to PV is roughly 1/4 or 25% of the value. The lower you can make this value, the better the mirror's surface.
Your friends has an RMS of 0.016 and a PV of 0.99. The RMS value here is almost exactly 1/6 or 17%, much better than normal.
One of the reasons he will be able to see small amplitude bumps on his mirror, most of which are less than 1/20PV high, is because he has Hilux coatings. This meanss that when tested on a Foucault test, a much narrower slit lightsource is used, and a far more sensitive test is performed which will see much smaller errors easier.
Unless something has happened to this mirror since it left us in terms of the surface changing shape, the mirror is an exceptionally good mirror. If he wishes to return the mirror we can of course re-test it and issue a report. If the mirror has gone faulty (would be exceptionally rare) we would of course, replace it at our cost, even though it is 2 years old.
I feel that since you sent a message to the Oriontelescope group with this complaint of your friends, it is fitting I post this reply to the group and also upload the Zygo file for them to see also.
Regards
Barry
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John, how could this value be wrong unless input manually?
I thought these were generated automatically. If they are input manually
then what the point?
If not, then this does raise some interesting questions.
John
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Hi John,
If you notice I deleted that last corrective mail. I thought I had put the decimal in the wrong place in the email, but hadn't.
The Zygo actual report is automatic, it was me misreading the decimal place wrong in the mail I sent.
Regards
Barry
Un saludo.
alucino....
