Surplus Shed is currently offering a limited number of "new", old-stock objectives from A. Jaegers, up to 6" aperture. The clever ATM could build a really nice refractor for a small fraction of an equivalent commercial refractor. 3 pages of Jaegers listings, starting here: http://www.surplusshed.com/pages/category/jaegersobjectives_1.html They also have cells for some of them. I grabbed a few while the grabbing was good. Jaegers objectives are remarkably good for their price, even back in the old days. I would rate them a notch higher than the Chinese lenses currently flooding the market. Fred at Surplus Shed is testing the large ones, and making registration marks on the edges for rotational alignment of the elements. Most are not coated, but that is of minimal concern. You may even be able to find a local lab to coat them for you, for a fee, if you can't live without a coating. There is also an old-fashioned method that allows kitchen chemists to coat their own lenses. A vacuum chamber is not required. I grabbed the 6" f/5, f/10, & f/15, as well as several smaller sizes. The cells require 7" aluminum tubing. Harward Irrigation in Utah county sells it. I made the 3" finder on the Ealing at SPOC, using a Jaegers objective donated by Siegfried.
Hi, Thanks for the information. I ordered the 6" mirror cell and Objectives. I am assuming I only need 1 mirror cell? Mark ________________________________ From: Chuck Hards <chuck.hards@gmail.com> To: Utah Astronomy <utah-astronomy@mailman.xmission.com> Sent: Tuesday, September 20, 2011 9:03 AM Subject: [Utah-astronomy] Refractors on the cheap Surplus Shed is currently offering a limited number of "new", old-stock objectives from A. Jaegers, up to 6" aperture. The clever ATM could build a really nice refractor for a small fraction of an equivalent commercial refractor. 3 pages of Jaegers listings, starting here: http://www.surplusshed.com/pages/category/jaegersobjectives_1.html They also have cells for some of them. I grabbed a few while the grabbing was good. Jaegers objectives are remarkably good for their price, even back in the old days. I would rate them a notch higher than the Chinese lenses currently flooding the market. Fred at Surplus Shed is testing the large ones, and making registration marks on the edges for rotational alignment of the elements. Most are not coated, but that is of minimal concern. You may even be able to find a local lab to coat them for you, for a fee, if you can't live without a coating. There is also an old-fashioned method that allows kitchen chemists to coat their own lenses. A vacuum chamber is not required. I grabbed the 6" f/5, f/10, & f/15, as well as several smaller sizes. The cells require 7" aluminum tubing. Harward Irrigation in Utah county sells it. I made the 3" finder on the Ealing at SPOC, using a Jaegers objective donated by Siegfried. _______________________________________________ Utah-Astronomy mailing list Utah-Astronomy@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Visit the Photo Gallery: http://www.slas.us/gallery2/main.php
On 9/20/11, Mark Shelton <woodturninginc@yahoo.com> wrote:
Hi, Thanks for the information.
I ordered the 6" mirror cell and Objectives. I am assuming I only need 1 mirror cell?
Actually it's a lens cell, and both objective elements fit into it. You need one cell for each objective (each objective being one crown and one flint element). These are not push-pull cells, so getting your tubing precisely squared-on is almost a must- not a big deal in practice. It makes collimation much easier. Old-school, tried and true stuff. If you bought more than one objective, you'll need a cell for each. Which f/ratio(s) did you go for?
Chuck, I purchased the F10 60" focal length, 6" diameter. I am thinking long term of making a Wood Body for the scope. I have the capabilities of turning a 5 foot tube or so on the wood lathe. Just starting to think this project through. I will be making this most likely next summer or the summer after that. I think a wood turned telescope body would be fun and challenging to do. Mark ________________________________ From: Chuck Hards <chuck.hards@gmail.com> To: Utah Astronomy <utah-astronomy@mailman.xmission.com> Sent: Tuesday, September 20, 2011 10:48 AM Subject: Re: [Utah-astronomy] Refractors on the cheap On 9/20/11, Mark Shelton <woodturninginc@yahoo.com> wrote:
Hi, Thanks for the information.
I ordered the 6" mirror cell and Objectives. I am assuming I only need 1 mirror cell?
Actually it's a lens cell, and both objective elements fit into it. You need one cell for each objective (each objective being one crown and one flint element). These are not push-pull cells, so getting your tubing precisely squared-on is almost a must- not a big deal in practice. It makes collimation much easier. Old-school, tried and true stuff. If you bought more than one objective, you'll need a cell for each. Which f/ratio(s) did you go for? _______________________________________________ Utah-Astronomy mailing list Utah-Astronomy@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Visit the Photo Gallery: http://www.slas.us/gallery2/main.php
Great project Mark! A wood tubed refractor would be exceptionally cool. Not without challenges, but you are up to them. BTW, the octagonal wood tube for my 4" Newtonian finder turned out pretty good (at least for my woodworking abilities). It should be a working telescope before long. Mat -----Original Message----- From: utah-astronomy-bounces@mailman.xmission.com [mailto:utah-astronomy-bounces@mailman.xmission.com] On Behalf Of Mark Shelton Sent: Tuesday, September 20, 2011 1:09 PM To: Utah Astronomy Subject: Re: [Utah-astronomy] Refractors on the cheap Chuck, I purchased the F10 60" focal length, 6" diameter. I am thinking long term of making a Wood Body for the scope. I have the capabilities of turning a 5 foot tube or so on the wood lathe. Just starting to think this project through. I will be making this most likely next summer or the summer after that. I think a wood turned telescope body would be fun and challenging to do. Mark ________________________________ From: Chuck Hards <chuck.hards@gmail.com> To: Utah Astronomy <utah-astronomy@mailman.xmission.com> Sent: Tuesday, September 20, 2011 10:48 AM Subject: Re: [Utah-astronomy] Refractors on the cheap On 9/20/11, Mark Shelton <woodturninginc@yahoo.com> wrote:
Hi, Thanks for the information.
I ordered the 6" mirror cell and Objectives. I am assuming I only need 1 mirror cell?
Actually it's a lens cell, and both objective elements fit into it. You need one cell for each objective (each objective being one crown and one flint element). These are not push-pull cells, so getting your tubing precisely squared-on is almost a must- not a big deal in practice. It makes collimation much easier. Old-school, tried and true stuff. If you bought more than one objective, you'll need a cell for each. Which f/ratio(s) did you go for? _______________________________________________ Utah-Astronomy mailing list Utah-Astronomy@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Visit the Photo Gallery: http://www.slas.us/gallery2/main.php _______________________________________________ Utah-Astronomy mailing list Utah-Astronomy@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Visit the Photo Gallery: http://www.slas.us/gallery2/main.php ---------------------------------------------------------------------------- This message and any included attachments are from Siemens Medical Solutions and are intended only for the addressee(s). The information contained herein may include trade secrets or privileged or otherwise confidential information. Unauthorized review, forwarding, printing, copying, distributing, or using such information is strictly prohibited and may be unlawful. If you received this message in error, or have reason to believe you are not authorized to receive it, please promptly delete this message and notify the sender by e-mail with a copy to Central.SecurityOffice@siemens.com Thank you
Outstanding! Simply Outstanding! Mark Shelton headed down the Refractor Path. I cannot wait to see where this ends up in two or three years. :)
Date: Tue, 20 Sep 2011 10:09:10 -0700 From: woodturninginc@yahoo.com To: utah-astronomy@mailman.xmission.com Subject: Re: [Utah-astronomy] Refractors on the cheap
Chuck, I purchased the F10 60" focal length, 6" diameter. I am thinking long term of making a Wood Body for the scope. I have the capabilities of turning a 5 foot tube or so on the wood lathe. Just starting to think this project through. I will be making this most likely next summer or the summer after that. I think a wood turned telescope body would be fun and challenging to do.
Mark
________________________________ From: Chuck Hards <chuck.hards@gmail.com> To: Utah Astronomy <utah-astronomy@mailman.xmission.com> Sent: Tuesday, September 20, 2011 10:48 AM Subject: Re: [Utah-astronomy] Refractors on the cheap
On 9/20/11, Mark Shelton <woodturninginc@yahoo.com> wrote:
Hi, Thanks for the information.
I ordered the 6" mirror cell and Objectives. I am assuming I only need 1 mirror cell?
Actually it's a lens cell, and both objective elements fit into it. You need one cell for each objective (each objective being one crown and one flint element). These are not push-pull cells, so getting your tubing precisely squared-on is almost a must- not a big deal in practice. It makes collimation much easier. Old-school, tried and true stuff.
If you bought more than one objective, you'll need a cell for each. Which f/ratio(s) did you go for?
_______________________________________________ Utah-Astronomy mailing list Utah-Astronomy@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Visit the Photo Gallery: http://www.slas.us/gallery2/main.php _______________________________________________ Utah-Astronomy mailing list Utah-Astronomy@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Visit the Photo Gallery: http://www.slas.us/gallery2/main.php
On 9/20/11, Mark Shelton <woodturninginc@yahoo.com> wrote:
Chuck, I purchased the F10 60" focal length, 6" diameter. I am thinking long term of making a Wood Body for the scope. I have the capabilities of turning a 5 foot tube or so on the wood lathe. Just starting to think this project through. I will be making this most likely next summer or the summer after that. I think a wood turned telescope body would be fun and challenging to do.
Mark, you read my mind. I was going to suggest a wood tube. With your abilities and lathe, I'm sure it will be outstanding. I'll look up some wooden-tube telescopes soon, from the S&T archives.
Chuck, Thanks for looking wooden- tubes up for me. I do not have access to old S&T. Can you send me any info you find? It would be great to see more information on a telescope........ like I am thinks about. O BOY I AM GETTING EXCITED ALL READY. Mark ________________________________ From: Chuck Hards <chuck.hards@gmail.com> To: Utah Astronomy <utah-astronomy@mailman.xmission.com> Sent: Tuesday, September 20, 2011 11:29 AM Subject: Re: [Utah-astronomy] Refractors on the cheap On 9/20/11, Mark Shelton <woodturninginc@yahoo.com> wrote:
Chuck, I purchased the F10 60" focal length, 6" diameter. I am thinking long term of making a Wood Body for the scope. I have the capabilities of turning a 5 foot tube or so on the wood lathe. Just starting to think this project through. I will be making this most likely next summer or the summer after that. I think a wood turned telescope body would be fun and challenging to do.
Mark, you read my mind. I was going to suggest a wood tube. With your abilities and lathe, I'm sure it will be outstanding. I'll look up some wooden-tube telescopes soon, from the S&T archives. _______________________________________________ Utah-Astronomy mailing list Utah-Astronomy@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Visit the Photo Gallery: http://www.slas.us/gallery2/main.php
On 9/20/11, Mark Shelton <woodturninginc@yahoo.com> wrote:
Chuck, Thanks for looking wooden- tubes up for me. I do not have access to old S&T. Can you send me any info you find?
OK, things are not going well this morning. My home computer won't run the S&T digital collection at all (8 years old, not enough memory, too slow), and for some reason, today my work computer will only run the index but I can't open individual issues. This is strange because I've opened the DVD's here many times before. I think I smell an IT guy doing things when I'm not around... My ex-wife got the new computer in the divorce and I got stuck with the dinosaur. Gonna be a while before I can spend the money on a new one, thanks to Surplus Shed lol. My paper copies of the magazine are boxed-up and in storage in the basement. I can't get to them until the weekend. I was hoping I could just email the digital versions, now I'll have to scan the paper copies before sending them. Patience.
Thank you very much Mark ________________________________ From: Chuck Hards <chuck.hards@gmail.com> To: Utah Astronomy <utah-astronomy@mailman.xmission.com> Sent: Wednesday, September 21, 2011 6:55 AM Subject: Re: [Utah-astronomy] Refractors on the cheap On 9/20/11, Mark Shelton <woodturninginc@yahoo.com> wrote:
Chuck, Thanks for looking wooden- tubes up for me. I do not have access to old S&T. Can you send me any info you find?
OK, things are not going well this morning. My home computer won't run the S&T digital collection at all (8 years old, not enough memory, too slow), and for some reason, today my work computer will only run the index but I can't open individual issues. This is strange because I've opened the DVD's here many times before. I think I smell an IT guy doing things when I'm not around... My ex-wife got the new computer in the divorce and I got stuck with the dinosaur. Gonna be a while before I can spend the money on a new one, thanks to Surplus Shed lol. My paper copies of the magazine are boxed-up and in storage in the basement. I can't get to them until the weekend. I was hoping I could just email the digital versions, now I'll have to scan the paper copies before sending them. Patience. _______________________________________________ Utah-Astronomy mailing list Utah-Astronomy@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Visit the Photo Gallery: http://www.slas.us/gallery2/main.php
Hi Chuck, I've been able to pick up several decent surplus computers from USU for really reasonable prices. I would bet that the U of U as well as other universities also have the same types of deals. You may want to check with Kurt or others to see where on campus they sell surplus computers. Clear skies, Dale.
-----Original Message----- From: utah-astronomy-bounces@mailman.xmission.com [mailto:utah- astronomy-bounces@mailman.xmission.com] On Behalf Of Chuck Hards Sent: Wednesday, September 21, 2011 6:56 AM To: Utah Astronomy Subject: Re: [Utah-astronomy] Refractors on the cheap
On 9/20/11, Mark Shelton <woodturninginc@yahoo.com> wrote:
Chuck, Thanks for looking wooden- tubes up for me. I do not have access to old S&T. Can you send me any info you find?
OK, things are not going well this morning.
My home computer won't run the S&T digital collection at all (8 years old, not enough memory, too slow), and for some reason, today my work computer will only run the index but I can't open individual issues. This is strange because I've opened the DVD's here many times before. I think I smell an IT guy doing things when I'm not around...
My ex-wife got the new computer in the divorce and I got stuck with the dinosaur. Gonna be a while before I can spend the money on a new one, thanks to Surplus Shed lol.
My paper copies of the magazine are boxed-up and in storage in the basement. I can't get to them until the weekend. I was hoping I could just email the digital versions, now I'll have to scan the paper copies before sending them.
Patience.
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On 9/21/11, Dale Hooper <Dale.Hooper@sdl.usu.edu> wrote:
Hi Chuck,
I've been able to pick up several decent surplus computers from USU for really reasonable prices. I would bet that the U of U as well as other universities also have the same types of deals. You may want to check with Kurt or others to see where on campus they sell surplus computers.
Thanks for the tip, Dale. I've got a few hundred saved up for a new machine, it's not too far off, probably October. I'm trying now to decide if I want to get a new tower or just go for a laptop with all the bells and whistles. I used to work with a guy who was in the UofU surplus department, I should look him up and see if he's still there.
Go with the laptop. Towers are pretty "passe" at this point. If you like larger screens, you can set up a "docket" and have as big a screen as you want. ----- Original Message ----- From: "Chuck Hards" <chuck.hards@gmail.com> To: "Utah Astronomy" <utah-astronomy@mailman.xmission.com> Sent: Wednesday, September 21, 2011 11:13:18 AM Subject: Re: [Utah-astronomy] Refractors on the cheap On 9/21/11, Dale Hooper <Dale.Hooper@sdl.usu.edu> wrote:
Hi Chuck,
I've been able to pick up several decent surplus computers from USU for really reasonable prices. I would bet that the U of U as well as other universities also have the same types of deals. You may want to check with Kurt or others to see where on campus they sell surplus computers.
Thanks for the tip, Dale. I've got a few hundred saved up for a new machine, it's not too far off, probably October. I'm trying now to decide if I want to get a new tower or just go for a laptop with all the bells and whistles. I used to work with a guy who was in the UofU surplus department, I should look him up and see if he's still there. _______________________________________________ Utah-Astronomy mailing list Utah-Astronomy@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Visit the Photo Gallery: http://www.slas.us/gallery2/main.php
On 9/21/11, jcarman6@q.com <jcarman6@q.com> wrote:
Go with the laptop. Towers are pretty "passe" at this point. If you like larger screens, you can set up a "docket" and have as big a screen as you want.
Actually I'm hearing that laptops are on their way out as well. I have a fairly new 24" monitor and will probably get a second, to facilitate using SolidWorks at home (3D design software). I also like my workstation in one place, I'm not the kind of person to tote a computer around the house with me. A tower would help keep the computer time compartmentalized and not intruding on real life. We'll see what shakes out, though I am leaning toward the laptop, it's not because of market trends.
On 9/20/11, Mark Shelton <woodturninginc@yahoo.com> wrote:
Chuck, Thanks for looking wooden- tubes up for me. I do not have access to old S&T. Can you send me any info you find?
Here are some online references for you, until I dig through the old S&T's: http://www.cfellows.com/MakNewt.htm http://www.tulsawalk.com/projects/telescope/tube.html http://hackaday.com/2010/05/17/building-an-oak-telescope/ http://www.mdpub.com/scopeworks/woody.html
BTW, though I've never built a wooden tube for the telescope, I have made many wooden forms for fiberglass tubes. It's essentially the same process, only the form is made with hollow bracing for the optical path, instead of solid bulkheads. I use the "coopered" method and either lathe-turn to final OD (ID for a fiberglass form), or hand-work if too large for the lathe.
Mark,
I have back issues of ATM Journal with some wood tube refractors. Even if you decide to go with aluminum tubing there is still plenty of woodworking that can be done for a tripod and rocker box. Erik On 9/20/11, Mark Shelton <woodturninginc@yahoo.com> wrote:
Chuck, I purchased the F10 60" focal length, 6" diameter. I am thinking long term of making a Wood Body for the scope. I have the capabilities of turning a 5 foot tube or so on the wood lathe. Just starting to think this project through. I will be making this most likely next summer or the summer after that. I think a wood turned telescope body would be fun and challenging to do.
Mark, you read my mind. I was going to suggest a wood tube. With your abilities and lathe, I'm sure it will be outstanding. I'll look up some wooden-tube telescopes soon, from the S&T archives.
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COOL, I will be over to take a look at them soon. Thanks Eric Mark ________________________________ From: "erikhansen@thebluezone.net" <erikhansen@thebluezone.net> To: Utah Astronomy <utah-astronomy@mailman.xmission.com> Sent: Tuesday, September 20, 2011 11:38 AM Subject: Re: [Utah-astronomy] Refractors on the cheap
Mark,
I have back issues of ATM Journal with some wood tube refractors. Even if you decide to go with aluminum tubing there is still plenty of woodworking that can be done for a tripod and rocker box. Erik On 9/20/11, Mark Shelton <woodturninginc@yahoo.com> wrote:
Chuck, I purchased the F10 60" focal length, 6" diameter. I am thinking long term of making a Wood Body for the scope. I have the capabilities of turning a 5 foot tube or so on the wood lathe. Just starting to think this project through. I will be making this most likely next summer or the summer after that. I think a wood turned telescope body would be fun and challenging to do.
Mark, you read my mind. I was going to suggest a wood tube. With your abilities and lathe, I'm sure it will be outstanding. I'll look up some wooden-tube telescopes soon, from the S&T archives.
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Some people have cheated and simply skinned a sonotube with veneer. Doesn't look too bad at all if you don't screw up the seam.
Refractor vs Reflector.
For the most part do you buy a large reflector to look at double stars? A good 6 inch refractor is less expensive than a large newt and much easier to set up and lighter as well. No collimation required. it seems seeing rarely allows full utilization of big appature scopes. I will still maintain I would rather a 5 inch F6 Astrophysics APO over any other size. On the majority of objects it will resolve objects as good as anything. Atmospheric conditions seem almost always limit resolving. Buy something for 80% of your observing not 20%. Match your observing with your telescope. With a big newtonian I had little desire to look at anything but deep sky. Erik Surplus Shed is currently offering a limited number of "new",
old-stock objectives from A. Jaegers, up to 6" aperture. The clever ATM could build a really nice refractor for a small fraction of an equivalent commercial refractor.
3 pages of Jaegers listings, starting here:
http://www.surplusshed.com/pages/category/jaegersobjectives_1.html
They also have cells for some of them.
I grabbed a few while the grabbing was good.
Jaegers objectives are remarkably good for their price, even back in the old days. I would rate them a notch higher than the Chinese lenses currently flooding the market. Fred at Surplus Shed is testing the large ones, and making registration marks on the edges for rotational alignment of the elements. Most are not coated, but that is of minimal concern. You may even be able to find a local lab to coat them for you, for a fee, if you can't live without a coating. There is also an old-fashioned method that allows kitchen chemists to coat their own lenses. A vacuum chamber is not required.
I grabbed the 6" f/5, f/10, & f/15, as well as several smaller sizes. The cells require 7" aluminum tubing. Harward Irrigation in Utah county sells it.
I made the 3" finder on the Ealing at SPOC, using a Jaegers objective donated by Siegfried.
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Either that or three refractors, one small, one medium and one GREAT BIG! I'm 2/3 of the way there. I'm thinkin 11" f/15 or longer would be nice. Perhaps the one in Orem will come available after I win the Lotto! Steve
Date: Tue, 20 Sep 2011 12:14:02 -0600 From: chuck.hards@gmail.com To: utah-astronomy@mailman.xmission.com Subject: Re: [Utah-astronomy] Refractors on the cheap
My philosophy is to have one of everything. I'm covered. ;-)
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On 9/20/11, Steve Fisher <iotacass1@hotmail.com> wrote:
Either that or three refractors, one small, one medium and one GREAT BIG! I'm 2/3 of the way there. I'm thinkin 11" f/15 or longer would be nice.
In terms of square inches of objective aperture, you're not even halfway there. ;-)
Depends on what "there" is if you ask me. ;)
Date: Tue, 20 Sep 2011 12:31:38 -0600 From: chuck.hards@gmail.com To: utah-astronomy@mailman.xmission.com Subject: Re: [Utah-astronomy] Refractors on the cheap
On 9/20/11, Steve Fisher <iotacass1@hotmail.com> wrote:
Either that or three refractors, one small, one medium and one GREAT BIG! I'm 2/3 of the way there. I'm thinkin 11" f/15 or longer would be nice.
In terms of square inches of objective aperture, you're not even halfway there. ;-)
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On 9/20/11, Steve Fisher <iotacass1@hotmail.com> wrote:
Depends on what "there" is if you ask me. ;)
You better get that big refractor quickly. A couple more years and it will be too big and heavy for a person of your advanced years. I want you to enjoy the time you have left. ;-)
On 9/20/11, Steve Fisher <iotacass1@hotmail.com> wrote:
I'm thinkin 11" f/15 or longer would be nice. Perhaps the one in Orem will come available after I win the Lotto!
Steve, have you considered grinding and polishing your own large doublet? All the surfaces are spherical, so they are a snap to figure. Chasing down wedge is usually the only tedious part, and that can be avoided with care.
BTW, if you do opt for one of the Surplus Shed Jaegers objectives, don't use masking tape for spacing as Fred suggests. Use the metal-foil tape that HVAC techs use to make AC coil housings air-tight. You can cut tiny sections with scissors. I have some if anyone needs it. Another option is to oil-space them. This effectively eliminates two air-to-glass surfaces. Can be messy if you don't get the edges sealed completely. Never cement an achromat over about 5" aperture, as differential flexure will pop them apart or damage them. On 9/20/11, Chuck Hards <chuck.hards@gmail.com> wrote:
On 9/20/11, Steve Fisher <iotacass1@hotmail.com> wrote:
I'm thinkin 11" f/15 or longer would be nice. Perhaps the one in Orem will come available after I win the Lotto!
Steve, have you considered grinding and polishing your own large doublet? All the surfaces are spherical, so they are a snap to figure. Chasing down wedge is usually the only tedious part, and that can be avoided with care.
Chuck: I know for sure that I will never grind a lens or even a mirror for that matter. I simply have proven to many times in my life that Patience like that is not one of my virtues. I almost completed a 17" Dob once but sold if off before completion. Years of experience have proven that I am exceptionally skilled at writing checks and opening packages. NOT fabricating optics.
Date: Tue, 20 Sep 2011 13:04:39 -0600 From: chuck.hards@gmail.com To: utah-astronomy@mailman.xmission.com Subject: Re: [Utah-astronomy] Refractors on the cheap
On 9/20/11, Steve Fisher <iotacass1@hotmail.com> wrote:
I'm thinkin 11" f/15 or longer would be nice. Perhaps the one in Orem will come available after I win the Lotto!
Steve, have you considered grinding and polishing your own large doublet? All the surfaces are spherical, so they are a snap to figure. Chasing down wedge is usually the only tedious part, and that can be avoided with care.
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On 9/20/11, Steve Fisher <iotacass1@hotmail.com> wrote:
Chuck: I know for sure that I will never grind a lens or even a mirror for that matter. I simply have proven to many times in my life that Patience like that is not one of my virtues. I almost completed a 17" Dob once but sold if off before completion. Years of experience have proven that I am exceptionally skilled at writing checks and opening packages. NOT fabricating optics.
Well my friend, I'm just thinking of ways to get you into that big refractor without having to rob an armored car or sell weed, ya know?
They used to have a nice 4.125 lens, F/15. Anything like that available? On Sep 20, 2011 9:03 AM, "Chuck Hards" <chuck.hards@gmail.com> wrote:
Surplus Shed is currently offering a limited number of "new", old-stock objectives from A. Jaegers, up to 6" aperture. The clever ATM could build a really nice refractor for a small fraction of an equivalent commercial refractor.
3 pages of Jaegers listings, starting here:
http://www.surplusshed.com/pages/category/jaegersobjectives_1.html
They also have cells for some of them.
I grabbed a few while the grabbing was good.
Jaegers objectives are remarkably good for their price, even back in the old days. I would rate them a notch higher than the Chinese lenses currently flooding the market. Fred at Surplus Shed is testing the large ones, and making registration marks on the edges for rotational alignment of the elements. Most are not coated, but that is of minimal concern. You may even be able to find a local lab to coat them for you, for a fee, if you can't live without a coating. There is also an old-fashioned method that allows kitchen chemists to coat their own lenses. A vacuum chamber is not required.
I grabbed the 6" f/5, f/10, & f/15, as well as several smaller sizes. The cells require 7" aluminum tubing. Harward Irrigation in Utah county sells it.
I made the 3" finder on the Ealing at SPOC, using a Jaegers objective donated by Siegfried.
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On 9/22/11, Siegfried Jachmann <siegfried@jachmann.org> wrote:
They used to have a nice 4.125 lens, F/15. Anything like that available?
Looks like they do! http://www.surplusshed.com/pages/item/l10607j.html
participants (8)
-
Chuck Hards -
Dale Hooper -
erikhansen＠thebluezone.net -
Hutchings, Mat (H USA) -
jcarman6＠q.com -
Mark Shelton -
Siegfried Jachmann -
Steve Fisher