RE: [Utah-astronomy] Interesting view
I guess that technically glaciers flow. I don't think they are very gentle though. Dave -----Original Message----- From: utah-astronomy-bounces+david.dunn=albertsons.com@mailman.xmission.com [mailto:utah-astronomy-bounces+david.dunn=albertsons.com@mailman.xmission.co m] On Behalf Of Joe Bauman Sent: Wednesday, April 07, 2004 1:29 PM To: Utah Astronomy Subject: Re: [Utah-astronomy] Interesting view Not too much on chronology that I know of, except Rover scientists believe the rocks were laid down in "gently flowing liquid water," a description posted by Cornell University. (It's hard to understand how it could be gently flowing if it wasn't liquid, but that's an issue for the Department of Redundancy Dept.) -- Joe _______________________________________________ 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.utahastronomy.com
Hi, I'm hoping one of our list folks can give me some information as soon as convenient. I'm planning to head out for some astrophotography soon, and as I was working on some problems (like making a hyperfocal lens), I had the telescope set up during the daytime. This gave me a good look at the corrector plate and it was fairly dusty. The last time I cleaned a corrector plate was with my old Celestron 8" and I really screwed things up -- I took the corrector off and failed to note its alignment, so I got it back on wrong. I was never again able to collimate it well. Now with my new 12" I don't want to make mistakes and I won't be taking the corrector off. What I would like someone to tell me -- particularly an experienced old hand like Patrick, Chuck, Siegfried, Bruce, etc., etc. -- is a good, safe, quick way to clean the dust from the surface of the corrector. Any suggestions? Or does anyone have any stories to share on this? Thanks very much, Joe
The rule of thumb for cleaning telescope mirrors is - DON'T. Unless the mirror is extremely dusty, it doesn't need cleaning. All the dust will do is offend your sensibility. The image will not change by cleaning. Brent --- Joe Bauman <bau@desnews.com> wrote:
Hi, I'm hoping one of our list folks can give me some information as soon as convenient. I'm planning to head out for some astrophotography soon, and as I was working on some problems (like making a hyperfocal lens), I had the telescope set up during the daytime. This gave me a good look at the corrector plate and it was fairly dusty. The last time I cleaned a corrector plate was with my old Celestron 8" and I really screwed things up -- I took the corrector off and failed to note its alignment, so I got it back on wrong. I was never again able to collimate it well. Now with my new 12" I don't want to make mistakes and I won't be taking the corrector off.
What I would like someone to tell me -- particularly an experienced old hand like Patrick, Chuck, Siegfried, Bruce, etc., etc. -- is a good, safe, quick way to clean the dust from the surface of the corrector. Any suggestions? Or does anyone have any stories to share on this?
Thanks very much, Joe
_______________________________________________ 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.utahastronomy.com
__________________________________ Do you Yahoo!? Yahoo! Small Business $15K Web Design Giveaway http://promotions.yahoo.com/design_giveaway/
Hi Brent, Maybe I didn't pharse that right. It's an SCT. I don't want to clean the mirror, just the surface of the glass on top, immediately under the lens cap. I thought that was the corrector plate, but maybe I'm wrong! -- Joe
Same advice. If you don't know how to collimate your telescope, don't take it apart. And Brent is right. The dust has to be almost opaque before you'll notice degredation in an image. Let sleeping dogs lie. --- Joe Bauman <bau@desnews.com> wrote:
Hi Brent, Maybe I didn't pharse that right. It's an SCT. I don't want to clean the mirror, just the surface of the glass on top, immediately under the lens cap. I thought that was the corrector plate, but maybe I'm wrong! -- Joe
_______________________________________________ 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.utahastronomy.com
__________________________________ Do you Yahoo!? Yahoo! Small Business $15K Web Design Giveaway http://promotions.yahoo.com/design_giveaway/
Hi Joe Just blow it off with a hand bulb blower like they sell at camera stores. Do not use compressed air. Do not use any liquids they just make it worse. I have never seen any improvement when using the scope after cleaning. Clear Skies Don Colton -----Original Message----- From: utah-astronomy-bounces+djcolton=piol.com@mailman.xmission.com [mailto:utah-astronomy-bounces+djcolton=piol.com@mailman.xmission.com]On Behalf Of Joe Bauman Sent: Tuesday, April 13, 2004 8:50 AM To: Utah Astronomy Subject: Re: [Utah-astronomy] seeking advice Hi Brent, Maybe I didn't pharse that right. It's an SCT. I don't want to clean the mirror, just the surface of the glass on top, immediately under the lens cap. I thought that was the corrector plate, but maybe I'm wrong! -- Joe _______________________________________________ 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.utahastronomy.com
Hi, Lowell Lyon called last night, wondering if anyone might be going up to the gravel quarry tonight (Tuesday). I told him I would post the question here for him, since he does not have access to the group at this time. So... Any takers?
As others have said unless it REALLY needs cleaning, don't bother. The corrector really has to be dirty to even consider cleaning. That said, I'll mention that during the recent rebuild of my C-14 I had everything apart anyway ( http://planet.state.ut.us/slas/patrickw/PATRICKW660.JPG ) so I said "oh the heck with it!" or something to that effect and removed the secondary housing from the corrector (it was loose anyway) so all I had was a large, round piece of glass. Into a sink of warm soapy water it went. Some light strokes with very wet and soggy paper towels (from center to rim with no circular motions), then a rinse with warm tap water followed by a couple rinses with a mix of distilled water and Everclear (40/60). Then let it air dry and picked off individual beads of water with the corners of paper towels. Reassembled and (believe it or not) it works! Needless to say this was done only after marking everything so I could get it all back the way it came apart. But again, if it's not really dirty, don't bother. Patrick
Paper should not be used on optics, even if wet. Paper is very abrasive, and will microscratch just about anything. Instead of paper towels, a cotton puff (real cotton, not a synthetic)should be used. --- Patrick Wiggins <paw@trilobyte.net> wrote:
As others have said unless it REALLY needs cleaning, don't bother. The corrector really has to be dirty to even consider cleaning.
That said, I'll mention that during the recent rebuild of my C-14 I had everything apart anyway (
http://planet.state.ut.us/slas/patrickw/PATRICKW660.JPG
) so I said "oh the heck with it!" or something to that effect and removed the secondary housing from the corrector (it was loose anyway) so all I had was a large, round piece of glass.
Into a sink of warm soapy water it went. Some light strokes with very wet and soggy paper towels (from center to rim with no circular motions), then a rinse with warm tap water followed by a couple rinses with a mix of distilled water and Everclear (40/60).
Then let it air dry and picked off individual beads of water with the corners of paper towels.
Reassembled and (believe it or not) it works!
Needless to say this was done only after marking everything so I could get it all back the way it came apart.
But again, if it's not really dirty, don't bother.
Patrick
_______________________________________________ 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.utahastronomy.com
__________________________________ Do you Yahoo!? Yahoo! Small Business $15K Web Design Giveaway http://promotions.yahoo.com/design_giveaway/
I use two cloth products that are pretty good (never paper lens tissue). Spontex Microfibre Cleaning Cloth and the other is 3M/Scotchbrite High Performance Cloth #2010. These were found in a local CostCo and are washable and reusable.
Exactly right. Also, direction of wipe isn't as important as rotating the wipe. The idea is to lift the collected grime away from the surface and not grind it in as you wipe. --- Brent Watson <brentjwatson@yahoo.com> wrote:
Paper should not be used on optics, even if wet. Paper is very abrasive, and will microscratch just about anything. Instead of paper towels, a cotton puff (real cotton, not a synthetic)should be used.
--- Patrick Wiggins <paw@trilobyte.net> wrote:
As others have said unless it REALLY needs cleaning, don't bother. The corrector really has to be dirty to even consider cleaning.
That said, I'll mention that during the recent rebuild of my C-14 I had everything apart anyway (
http://planet.state.ut.us/slas/patrickw/PATRICKW660.JPG
) so I said "oh the heck with it!" or something to that effect and removed the secondary housing from the corrector (it was loose anyway) so all I had was a large, round piece of glass.
Into a sink of warm soapy water it went. Some light strokes with very wet and soggy paper towels (from center to rim with no circular motions), then a rinse with warm tap water followed by a couple rinses with a mix of distilled water and Everclear (40/60).
Then let it air dry and picked off individual beads of water with the corners of paper towels.
Reassembled and (believe it or not) it works!
Needless to say this was done only after marking everything so I could get it all back the way it came apart.
But again, if it's not really dirty, don't bother.
Patrick
_______________________________________________ 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.utahastronomy.com
__________________________________ Do you Yahoo!? Yahoo! Small Business $15K Web Design Giveaway http://promotions.yahoo.com/design_giveaway/
_______________________________________________ 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.utahastronomy.com
__________________________________ Do you Yahoo!? Yahoo! Small Business $15K Web Design Giveaway http://promotions.yahoo.com/design_giveaway/
On 13-Apr-04 7:12, Joe Bauman wrote:
good, safe, quick way to clean the dust from the surface of the corrector. Any suggestions? Or does anyone have any stories to share on this? When I worked with some engineers building a spectrograph, they cleaned optics using 2-propanol, kimwipes, and pure dry nitrogen (100% N2) at ~15 psi (or less). Everything was done with latex or vinyl gloves (no fingerprints on anything), and no soap or water. These optics run in vacuum (low or high), hence no residues can be tolerated; it takes "forever" to pump out a fingerprint.
They were very, very careful with the kimwipes. There were some nifty techniques for using the wipes, but since I never had to clean the optics, I didn't learn them. If using an alcohol to flush debris from the optics, nitrogen will evaporate it quickly, and leave no residue. Had the optics not been under vacuum, I doubt all the cleaning would have been considered worth the risk to the optics. I never saw them clean the front-surface mirror, and understood that to be a monumental undertaking (cleaning without destroying, that is). This is not a particularly practical scheme for a home shop, since most people don't have gallons of 2-proponal or kimwipes, much less tanks of N2 sitting around. -- We're sorry, but the number you have dialed is imaginary. Please rotate your phone 90 degrees and try again.
--- Paul Gettings <gettings@mines.utah.edu> wrote:
We're sorry, but the number you have dialed is imaginary. Please rotate your phone 90 degrees and try again.
Clockwise or counter-clockwise? If you are in your 40's or older and want a laugh, get ahold of an old rotary phone and watch a teenager try and use it... ("The buttons are fake, dad, they don't do anything!") __________________________________ Do you Yahoo!? Yahoo! Small Business $15K Web Design Giveaway http://promotions.yahoo.com/design_giveaway/
participants (9)
-
Brent Watson -
Chuck Hards -
David Dunn -
Don J. Colton -
Joe Bauman -
Josephine Grahn -
Patrick Wiggins -
Paul Gettings -
Rob Ratkowski