Re: [Utah-astronomy] Laser collimator
In addition to Glatter's collimator, I also recommend Glatter's blug, if you are collimating a fast Newt. It greatly simplifies the laser collimation process for planar holographic alignment. http://www.greatredspot.com/collimator.htm The 2003 S&T article is good, but dated. Carlin and the collimator makers have moved on from what Carlin wrote there. Although I am tempermentally anti-gear, this is one of few times I recommend shelling out the bucks for the current high-end Glatter collimator and blug, if you own a fast Newt. Spending a couple of hundred on the collimator and blug is justified. It saves endless hours of headaches down the road and improves pointing accuracy for target acquistion. The cheaper laser collimators are not machined well-enough to accurately collimate a fast Newt. Design-wise, Glatter collimator designs also have a larger the battery segregated from the laser. Every time you change the battery on a low-end laser colliminator, the collimator tool itself goes out of the alignment. For Newts, the holographic or planar collimator changes the workflow focus (no pun intended) away from collimation adjustments at the primary mirror towards making most of the adjustments to the secondary with only a final fine-tune tweak on primary mirror knobs. - Kurt P.S. - If anyone knows an upgrade for a secondary mirror holder, please let me know. I'd like to get away from Allen wrenches and screwdrivers towards a secondary mirror holder that is rock solid and adjusts with some kind of locking knobs. There was an interesting advanced secondary mirror holder design in the April or May S&T. Blug review (not favorable) http://www.cloudynights.com/item.php?item_id=1480 ____________________________________________________________________________________ Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try it now. http://mobile.yahoo.com/;_ylt=Ahu06i62sR8HDtDypao8Wcj9tAcJ
Kurt, Bryan Greer (Protostar) may have the secondary holder you are looking for. http://www.fpi-protostar.com/ Daniel's V-block method for checking laser co-axialism with the barrel is simple and sound. I must add that when I use a laser for collimation, I still base my final, critical adjustments (if needed) with a star-test- now there's a dirty word for you. I've been recommending Dick Suiter's book for years (Star-testing Astronomical Telescopes) and still do. Judging a diffraction pattern can be a difficult thing to do for many people, but if you can, you will possess a powerful tool, independant of commercial gadgetry.
Seems like a lot of hard core collimaters use the Star-Test to check their work. Accuracy of your dots, on secondary and primary, can affect colimation. The Star Test does not require dots. I think f5 and f6, for sure,collimation is rather straight forward and I would not bother with laser. F4 it gets a little trickier.
A refractor cures the collimation issues. Erik Kurt, Bryan Greer (Protostar) may have the secondary holder you are
looking for. http://www.fpi-protostar.com/
Daniel's V-block method for checking laser co-axialism with the barrel is simple and sound.
I must add that when I use a laser for collimation, I still base my final, critical adjustments (if needed) with a star-test- now there's a dirty word for you. I've been recommending Dick Suiter's book for years (Star-testing Astronomical Telescopes) and still do. Judging a diffraction pattern can be a difficult thing to do for many people, but if you can, you will possess a powerful tool, independant of commercial gadgetry. _______________________________________________ Utah-Astronomy mailing list Utah-Astronomy@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Visit the Photo Gallery: http://gallery.utahastronomy.com Visit the Wiki: http://www.utahastronomy.com
Kurt, it seems to me that you can't use the Blug on a closed-tube Newtonian, since you can't see it. Am I off the mark here? On Mon, Apr 21, 2008 at 1:33 PM, Canopus56 <canopus56@yahoo.com> wrote:
In addition to Glatter's collimator, I also recommend Glatter's blug, if you are collimating a fast Newt. It greatly simplifies the laser collimation process for planar holographic alignment.
I use one all the time on my closed tube Dobs. I can see the collimator in the focuser from the front of the tube. My Glatter collimator is about 4 inches long so it comes all the way to the end of the focus tube. Dave -----Original Message----- From: utah-astronomy-bounces@mailman.xmission.com [mailto:utah-astronomy-bounces@mailman.xmission.com] On Behalf Of Chuck Hards Sent: Tuesday, April 22, 2008 8:50 AM To: Utah Astronomy Subject: Re: [Utah-astronomy] Laser collimator Kurt, it seems to me that you can't use the Blug on a closed-tube Newtonian, since you can't see it. Am I off the mark here? On Mon, Apr 21, 2008 at 1:33 PM, Canopus56 <canopus56@yahoo.com> wrote:
In addition to Glatter's collimator, I also recommend Glatter's blug, if you are collimating a fast Newt. It greatly simplifies the laser collimation process for planar holographic alignment.
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I'm somewhat embarrassed to admit that I own a laser more expensive than Glatter's (LaserMax), but I bought it back when it was just over $200 (it's at least double that now), but it has also saved me countless hours and grief setting up my truss dob, and I actually like the "target" pattern it projects much better than the grid on the Glatter laser, FWIW. I've not had to center-dot my mirror, and the results are consistently very good. I bought this thing in 2000, have no idea what the battery in it is, but the beam is still super bright 8 years later. ____________________________________________________________________________________ Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try it now. http://mobile.yahoo.com/;_ylt=Ahu06i62sR8HDtDypao8Wcj9tAcJ
So, Dave, are you watching the reflection in the primary? On Tue, Apr 22, 2008 at 9:26 AM, Dunn, Dave <David.Dunn@supervalu.com> wrote:
I use one all the time on my closed tube Dobs. I can see the collimator in the focuser from the front of the tube. My Glatter collimator is about 4 inches long so it comes all the way to the end of the focus tube.
No not with the Barlow. The laser passing through the Barlow makes a large red glow that is hard to see through. What I do is first center the dot on the primary and back into the laser watching the primary mirror (with someone turning the knobs). Then I put the Barlow on and watch from the side. I can see the end of the collimator in the focus tube directly on my 10 and 16 inch scopes. I watch until the center circle is centered around the laser. I will take a look and see if I can see it on the 8" at the star party that I have this Thursday. It is an f/7 so I don't normally need to be that precise. The Glatter model that I have was bought in around 2000 and is the model that works in both 2" and 1.25" focusers. The 1.25" part of it makes it longer. I think that if it didn't have the part, it would be hard to see. Dave -----Original Message----- From: utah-astronomy-bounces@mailman.xmission.com [mailto:utah-astronomy-bounces@mailman.xmission.com] On Behalf Of Chuck Hards Sent: Tuesday, April 22, 2008 12:03 PM To: Utah Astronomy Subject: Re: [Utah-astronomy] Laser collimator So, Dave, are you watching the reflection in the primary? On Tue, Apr 22, 2008 at 9:26 AM, Dunn, Dave <David.Dunn@supervalu.com> wrote:
I use one all the time on my closed tube Dobs. I can see the collimator in the focuser from the front of the tube. My Glatter collimator is about 4 inches long so it comes all the way to the end of the focus tube.
_______________________________________________ Utah-Astronomy mailing list Utah-Astronomy@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Visit the Photo Gallery: http://gallery.utahastronomy.com Visit the Wiki: http://www.utahastronomy.com
Thanks, Dave. I'm thinking of the Blug, which is installed on the inside of the focuser. With that arraingement, you can't see it in a closed tube unless looking at it's reflection in the primary. I do like Glatter's green laser option, for collimating in daylight. Even more pricey, however. Also I can't wait to try a laser collimator on my binocular viewer attachment- see just how parallel those two optical trains actually are. On Tue, Apr 22, 2008 at 1:02 PM, Dunn, Dave <David.Dunn@supervalu.com> wrote:
No not with the Barlow. The laser passing through the Barlow makes a large red glow that is hard to see through. What I do is first center the dot on the primary and back into the laser watching the primary mirror (with someone turning the knobs). Then I put the Barlow on and watch from the side. I can see the end of the collimator in the focus tube directly on my 10 and 16 inch scopes. I watch until the center circle is centered around the laser. I will take a look and see if I can see it on the 8" at the star party that I have this Thursday. It is an f/7 so I don't normally need to be that precise.
The Glatter model that I have was bought in around 2000 and is the model that works in both 2" and 1.25" focusers. The 1.25" part of it makes it longer. I think that if it didn't have the part, it would be hard to see.
The Blug points toward opening of the scope not toward the mirror, so you can easily see it. But to be safe it is best to have it screw into the Barlow so it doesn't fall into the tube and land on the mirror see http://www.kendrickastro.com/astro/laser.html#BarlowedCollimator -----Original Message----- From: utah-astronomy-bounces@mailman.xmission.com [mailto:utah-astronomy-bounces@mailman.xmission.com] On Behalf Of Chuck Hards Sent: Tuesday, April 22, 2008 2:12 PM To: Utah Astronomy Subject: Re: [Utah-astronomy] Laser collimator Thanks, Dave. I'm thinking of the Blug, which is installed on the inside of the focuser. With that arraingement, you can't see it in a closed tube unless looking at it's reflection in the primary. I do like Glatter's green laser option, for collimating in daylight. Even more pricey, however. Also I can't wait to try a laser collimator on my binocular viewer attachment- see just how parallel those two optical trains actually are. On Tue, Apr 22, 2008 at 1:02 PM, Dunn, Dave <David.Dunn@supervalu.com> wrote:
No not with the Barlow. The laser passing through the Barlow makes a large red glow that is hard to see through. What I do is first center the dot on the primary and back into the laser watching the primary mirror (with someone turning the knobs). Then I put the Barlow on and watch from the side. I can see the end of the collimator in the focus tube directly on my 10 and 16 inch scopes. I watch until the center circle is centered around the laser. I will take a look and see if I can see it on the 8" at the star party that I have this Thursday. It is an f/7 so I don't normally need to be that precise.
The Glatter model that I have was bought in around 2000 and is the model that works in both 2" and 1.25" focusers. The 1.25" part of it makes it longer. I think that if it didn't have the part, it would be hard to see.
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participants (6)
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Canopus56 -
Chuck Hards -
Don J. Colton -
Dunn, Dave -
erikhansen＠TheBlueZone.net -
Richard Tenney