RE: [Utah-astronomy] Lasers and collimation questions
Don et al., I highly suggest that people read and spend some serious time at the Mel Bartels website. It will clear up a lot of misconceptions, and get you well on your way to a properly collimated scope. http://zebu.uoregon.edu/~mbartels/kolli/kolli.html It's best to use a sight tube to get you very close on the diagonal orientation. Then a simple (non-holographic) laser can be used to fine tune diagonal orientation and for adjusting the tilt of the primary. Perhaps once or twice in six years that we've tried, has the seeing been good enough to tweak the collimation of our 16" scope at adequately high power; and never good enough for the 24". Lasers are great for collimation because they can be used at night; but the assumption is made that the mechanical center of the mirror is the optical center. A Cheshire is a great tool, but not convenient if you want to tweak collimation after dark. A laser is a worthwhile addition to your toolkit. I hate to see people leaving with the idea that lasers can't do the job, they can do an excellent job. Jo Grahn
--- Josephine Grahn <bsi@xmission.com> wrote:
Perhaps once or twice in six years that we've tried, has the seeing been good enough to tweak the collimation of our 16" scope at adequately high power; and never good enough for the 24".
Jo, try stopping-down the aperture. It won't affect the accuracy of the collimation job, and will allow a star-test on a night not good enough to support a huge aperture at high magnifications. This will have the secondary benefit of increasing the obstruction in relation to the aperture, making the diffraction rings even easier to see. C. __________________________________ Do you Yahoo!? Yahoo! SiteBuilder - Free, easy-to-use web site design software http://sitebuilder.yahoo.com
Someone earlier in this thread mentioned a secondary mirror template for center-dotting purposes. Remember that if you have a fast system, the diagonal will not be centered. It must be off-centered slightly in order to provide an evenly illuminated focal plane. Hopefully the template will take this into account, I'm not familiar with the book mentioned. C. __________________________________ Do you Yahoo!? Yahoo! SiteBuilder - Free, easy-to-use web site design software http://sitebuilder.yahoo.com
Chuck Dave Kriege's book contains a wealth of information and yes the table that goes with the template gives the proper offset for many different configurations. The template has a line drawn precisely done the major axis and one down the minor axis so it is easy to mark the offset. Clear Skies Don Colton -----Original Message----- From: utah-astronomy-bounces@mailman.xmission.com [mailto:utah-astronomy-bounces@mailman.xmission.com]On Behalf Of Chuck Hards Sent: Tuesday, August 12, 2003 9:00 PM To: Visit http://www.utahastronomy.com for the photo gallery. Subject: RE: [Utah-astronomy] Lasers and collimation questions Someone earlier in this thread mentioned a secondary mirror template for center-dotting purposes. Remember that if you have a fast system, the diagonal will not be centered. It must be off-centered slightly in order to provide an evenly illuminated focal plane. Hopefully the template will take this into account, I'm not familiar with the book mentioned. C. __________________________________ Do you Yahoo!? Yahoo! SiteBuilder - Free, easy-to-use web site design software http://sitebuilder.yahoo.com _______________________________________________ Utah-Astronomy mailing list Utah-Astronomy@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy
Thanks, Don. I leafed-through it years ago, will pick up a copy and read it in detail. My editor at S&T recommeded it too, for some reason I didn't buy it at the time. For those interested in the star-test, both for mirror evaluation & collimation, I suggest Dick Suiter's book "Star-Testing Astronomical Telescopes". Might be a bit "long-haired" for the casual observer, but contains a wealth of information. C. --- "Don J. Colton" <djcolton@piol.com> wrote:
Chuck Dave Kriege's book contains a wealth of information and yes the table that goes with the template gives the proper offset for many different configurations. The template has a line drawn precisely done the major axis and one down the minor axis so it is easy to mark the offset. Clear Skies Don Colton
-----Original Message----- From: utah-astronomy-bounces@mailman.xmission.com
[mailto:utah-astronomy-bounces@mailman.xmission.com]On
Behalf Of Chuck Hards Sent: Tuesday, August 12, 2003 9:00 PM To: Visit http://www.utahastronomy.com for the photo gallery. Subject: RE: [Utah-astronomy] Lasers and collimation questions
Someone earlier in this thread mentioned a secondary mirror template for center-dotting purposes. Remember that if you have a fast system, the diagonal will not be centered. It must be off-centered slightly in order to provide an evenly illuminated focal plane. Hopefully the template will take this into account, I'm not familiar with the book mentioned.
C.
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The book is not currently available at Barns & Nobel. There are 2 book available from Amazon.com (sort of). One Used book listed for $46.00 but it is gone (I tried to get it), the othere one available from Amazon is $121.00 Jim Chuck Hards <chuckhards@yahoo.com> wrote: Thanks, Don. I leafed-through it years ago, will pick up a copy and read it in detail. My editor at S&T recommeded it too, for some reason I didn't buy it at the time. For those interested in the star-test, both for mirror evaluation & collimation, I suggest Dick Suiter's book "Star-Testing Astronomical Telescopes". Might be a bit "long-haired" for the casual observer, but contains a wealth of information. C. --- "Don J. Colton" wrote:
Chuck Dave Kriege's book contains a wealth of information and yes the table that goes with the template gives the proper offset for many different configurations. The template has a line drawn precisely done the major axis and one down the minor axis so it is easy to mark the offset. Clear Skies Don Colton
-----Original Message----- From: utah-astronomy-bounces@mailman.xmission.com
[mailto:utah-astronomy-bounces@mailman.xmission.com]On
Behalf Of Chuck Hards Sent: Tuesday, August 12, 2003 9:00 PM To: Visit http://www.utahastronomy.com for the photo gallery. Subject: RE: [Utah-astronomy] Lasers and collimation questions
Someone earlier in this thread mentioned a secondary mirror template for center-dotting purposes. Remember that if you have a fast system, the diagonal will not be centered. It must be off-centered slightly in order to provide an evenly illuminated focal plane. Hopefully the template will take this into account, I'm not familiar with the book mentioned.
C.
__________________________________ Do you Yahoo!? Yahoo! SiteBuilder - Free, easy-to-use web site design software http://sitebuilder.yahoo.com _______________________________________________ Utah-Astronomy mailing list Utah-Astronomy@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy --------------------------------- Do you Yahoo!? Yahoo! SiteBuilder - Free, easy-to-use web site design software
I just ordered a copy from Sky Publishing for $29.95 + S&H. --- Jim Gibson <xajax99@yahoo.com> wrote:
The book is not currently available at Barns & Nobel. There are 2 book available from Amazon.com (sort of). One Used book listed for $46.00 but it is gone (I tried to get it), the othere one available from Amazon is $121.00
Jim
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Jim Here is the link to buy the book the Dave Kriege or Suiter book for $29.95 : http://www.willbell.com/tm/index.htm Clear Skies Don Colton -----Original Message----- From: utah-astronomy-bounces@mailman.xmission.com [mailto:utah-astronomy-bounces@mailman.xmission.com]On Behalf Of Jim Gibson Sent: Wednesday, August 13, 2003 10:05 AM To: Visit http://www.utahastronomy.com for the photo gallery. Subject: RE: [Utah-astronomy] Lasers and collimation questions The book is not currently available at Barns & Nobel. There are 2 book available from Amazon.com (sort of). One Used book listed for $46.00 but it is gone (I tried to get it), the othere one available from Amazon is $121.00 Jim Chuck Hards <chuckhards@yahoo.com> wrote: Thanks, Don. I leafed-through it years ago, will pick up a copy and read it in detail. My editor at S&T recommeded it too, for some reason I didn't buy it at the time. For those interested in the star-test, both for mirror evaluation & collimation, I suggest Dick Suiter's book "Star-Testing Astronomical Telescopes". Might be a bit "long-haired" for the casual observer, but contains a wealth of information. C. --- "Don J. Colton" wrote: > Chuck > Dave Kriege's book contains a wealth of information > and yes the table that > goes with the template gives the proper offset for > many different configurations. The template has a > line drawn precisely done > the major axis and one down the minor axis so it is > easy to mark the offset. > Clear Skies > Don Colton > > -----Original Message----- > From: utah-astronomy-bounces@mailman.xmission.com > [mailto:utah-astronomy-bounces@mailman.xmission.com]On > Behalf Of Chuck > Hards > Sent: Tuesday, August 12, 2003 9:00 PM > To: Visit http://www.utahastronomy.com for the photo > gallery. > Subject: RE: [Utah-astronomy] Lasers and collimation > questions > > > > Someone earlier in this thread mentioned a secondary > mirror template for center-dotting purposes. > Remember > that if you have a fast system, the diagonal will > not > be centered. It must be off-centered slightly in > order to provide an evenly illuminated focal plane. > Hopefully the template will take this into account, > I'm not familiar with the book mentioned. > > C. __________________________________ Do you Yahoo!? Yahoo! SiteBuilder - Free, easy-to-use web site design software http://sitebuilder.yahoo.com _______________________________________________ Utah-Astronomy mailing list Utah-Astronomy@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy ---------------------------------------------------------------------------- -- Do you Yahoo!? Yahoo! SiteBuilder - Free, easy-to-use web site design software
Thanks Don Jim "Don J. Colton" <djcolton@piol.com> wrote: Jim Here is the link to buy the book the Dave Kriege or Suiter book for $29.95 : http://www.willbell.com/tm/index.htm Clear Skies Don Colton -----Original Message----- From: utah-astronomy-bounces@mailman.xmission.com [mailto:utah-astronomy-bounces@mailman.xmission.com]On Behalf Of Jim Gibson Sent: Wednesday, August 13, 2003 10:05 AM To: Visit http://www.utahastronomy.com for the photo gallery. Subject: RE: [Utah-astronomy] Lasers and collimation questions The book is not currently available at Barns & Nobel. There are 2 book available from Amazon.com (sort of). One Used book listed for $46.00 but it is gone (I tried to get it), the othere one available from Amazon is $121.00 Jim Chuck Hards <chuckhards@yahoo.com> wrote: Thanks, Don. I leafed-through it years ago, will pick up a copy and read it in detail. My editor at S&T recommeded it too, for some reason I didn't buy it at the time. For those interested in the star-test, both for mirror evaluation & collimation, I suggest Dick Suiter's book "Star-Testing Astronomical Telescopes". Might be a bit "long-haired" for the casual observer, but contains a wealth of information. C. --- "Don J. Colton" wrote:
Chuck Dave Kriege's book contains a wealth of information and yes the table that goes with the template gives the proper offset for many different configurations. The template has a line drawn precisely done the major axis and one down the minor axis so it is easy to mark the offset. Clear Skies Don Colton
-----Original Message----- From: utah-astronomy-bounces@mailman.xmission.com
[mailto:utah-astronomy-bounces@mailman.xmission.com]On
Behalf Of Chuck Hards Sent: Tuesday, August 12, 2003 9:00 PM To: Visit http://www.utahastronomy.com for the photo gallery. Subject: RE: [Utah-astronomy] Lasers and collimation questions
Someone earlier in this thread mentioned a secondary mirror template for center-dotting purposes. Remember that if you have a fast system, the diagonal will not be centered. It must be off-centered slightly in order to provide an evenly illuminated focal plane. Hopefully the template will take this into account, I'm not familiar with the book mentioned.
C.
__________________________________ Do you Yahoo!? Yahoo! SiteBuilder - Free, easy-to-use web site design software http://sitebuilder.yahoo.com _______________________________________________ Utah-Astronomy mailing list Utah-Astronomy@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy --------------------------------- Do you Yahoo!? Yahoo! SiteBuilder - Free, easy-to-use web site design software_______________________________________________ Utah-Astronomy mailing list Utah-Astronomy@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy --------------------------------- Do you Yahoo!? Yahoo! SiteBuilder - Free, easy-to-use web site design software
Fellow SLAS'ers I haven't had an opportunity to view Mars yet and I don't want to miss it! Will anyone be using SPOC2 this weekend and NOT mind it if I swung by for a peek? Thanks guys! Chris Russo __________________________________ Do you Yahoo!? Yahoo! SiteBuilder - Free, easy-to-use web site design software http://sitebuilder.yahoo.com
Chris: Tell Patrick that you will be there: paw@trilobyte.net. There is a Marswatch tentatively planned from 2 to 4am, weather permitting, but RSVP is requested. Chuck --- Chris Russo <crrjr70@yahoo.com> wrote:
Fellow SLAS'ers
I haven't had an opportunity to view Mars yet and I don't want to miss it! Will anyone be using SPOC2 this weekend and NOT mind it if I swung by for a peek? Thanks guys!
Chris Russo
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participants (5)
-
Chris Russo -
Chuck Hards -
Don J. Colton -
Jim Gibson -
Josephine Grahn