philjay Posted February 10, 2015 Share Posted February 10, 2015 Optics are only pristine when they are brand new, the rest of time they build up dirt and, with the case of mirrors, maybe some oxidation but with modern coatings this takes a long time to happen. We can live with a heck of alot of muck on optics and still get good views and when to clean or recoat is a matter of personal choice/preference. I for one put up with quite a bit of muck on my optics preferring to limit the number of times I clean because everytime you will cause some imperfection, no matter how small, on it unless you do it in lab conditions. I see Daz has looked at your mirrors and reckons they are ok but it looks like you have convinced yourself there is something wrong, so go for it but remember its risky. I had a 20 year old 8" mirror set which had oxidised awhile back, cleaning was no good BUT the views of Jupiter were dead sharp although milky and star tests showed faint but good intra and extra focal airy discs, again milky. So I suspect something else could be the cause of your problems. If you are really set on pristine optics have a word with Orion Optics they can recoat your mirror and they are just up the a50. I did it with my vintage 8" mentioned above Link to comment Share on other sites More sharing options...
Guest zidder Posted February 10, 2015 Share Posted February 10, 2015 Optics are only pristine when they are brand new, the rest of time they build up dirt and, with the case of mirrors, maybe some oxidation but with modern coatings this takes a long time to happen. We can live with a heck of alot of muck on optics and still get good views and when to clean or recoat is a matter of personal choice/preference. I for one put up with quite a bit of muck on my optics preferring to limit the number of times I clean because everytime you will cause some imperfection, no matter how small, on it unless you do it in lab conditions. I see Daz has looked at your mirrors and reckons they are ok but it looks like you have convinced yourself there is something wrong, so go for it but remember its risky. I had a 20 year old 8" mirror set which had oxidised awhile back, cleaning was no good BUT the views of Jupiter were dead sharp although milky and star tests showed faint but good intra and extra focal airy discs, again milky. So I suspect something else could be the cause of your problems. If you are really set on pristine optics have a word with Orion Optics they can recoat your mirror and they are just up the a50. I did it with my vintage 8" mentioned above Thanks for the input Phil. I haven't really convinced myself something is wrong, I don't know if there is something or not . Buying something second hand especially something delicate like a scope is a totally unknown quantity, Daz & Baz where kind enough to come round and check it out and set it up for me. I think once I can get to a meet and let someone have a look through it all my doubts will be dispelled Link to comment Share on other sites More sharing options...
philjay Posted February 10, 2015 Share Posted February 10, 2015 Oh and I stick with the "use nowt but mild soapy water, fairy liquid, to wash the mirrors, then wash down with distilled water and air dry" brigade. Also I advocate not touching the surface with anything not even a cotton bud. Link to comment Share on other sites More sharing options...
tuckstar Posted February 10, 2015 Share Posted February 10, 2015 Gary, not being funny but have you had your eyes checked out recently. Only reason I ask is that you seemed to have problems with my scope that night at Martyn's although mine had cleanish mirrors and was well collimated and looked fine to me, not saying my eyes are great. Just a thought. Link to comment Share on other sites More sharing options...
Brantuk Posted February 10, 2015 Share Posted February 10, 2015 Looks like the IPA advice I was given years ago was inadequate - better mixed 50/50 with water and just lightly sprayed - BWF instructions even mentions it. This article seems to wrap up cleaning lenses and mirrors all in one go: http://www.skyandtelescope.com/astronomy-resources/caring-for-your-optics/ Orion 1 Link to comment Share on other sites More sharing options...
Guest zidder Posted February 10, 2015 Share Posted February 10, 2015 Gary, not being funny but have you had your eyes checked out recently. Only reason I ask is that you seemed to have problems with my scope that night at Martyn's although mine had cleanish mirrors and was well collimated and looked fine to me, not saying my eyes are great. Just a thought. Andy, Did I not tell you I'm as blind as a Bat Not had them checked for a while, could be, which is why I think it would be useful if someone else had a go with it Link to comment Share on other sites More sharing options...
Orion Posted February 10, 2015 Share Posted February 10, 2015 err Kim, would not use isopropyl alcohol, propan 1-Ol is the main buffered constituent of Baader wonder fluid (35%), which is an isomer of iso propyl alcohol (propan 2Ol). Which is not recommended for mirror coatings. Why not? Isopropanol isn't acidic. Link to comment Share on other sites More sharing options...
Orion Posted February 10, 2015 Share Posted February 10, 2015 Have a look at Dion's video if you're desperate to clean your mirror. I followed it to the ether when I had my 200P and it went very well. Here's the link: http://youtu.be/0tRHYSzaRLk Does anyone else see Dions video playing with audio slowed right down although video is ok? Link to comment Share on other sites More sharing options...
Tweedledee Posted February 10, 2015 Share Posted February 10, 2015 It is all in sync for me Felix Link to comment Share on other sites More sharing options...
Orion Posted February 10, 2015 Share Posted February 10, 2015 Must be my galaxy tab10 Link to comment Share on other sites More sharing options...
catman161 Posted February 11, 2015 Share Posted February 11, 2015 It is all in sync for me Felix It was Derek asking Pete Orion 1 Link to comment Share on other sites More sharing options...
Tweedledee Posted February 11, 2015 Share Posted February 11, 2015 Doh! Must be his galaxy tab10 Orion and catman161 2 Link to comment Share on other sites More sharing options...
Guest zidder Posted February 11, 2015 Share Posted February 11, 2015 Having a look at astrobaby collimation guide came across this, a near on perfect example of what I was seeing when I did star test just off focus, except without the rings, maybe answers my query ? Link to comment Share on other sites More sharing options...
Guest Tweedledum Posted February 11, 2015 Share Posted February 11, 2015 It is always worth checking. If you follow her well written guide you should end up with your telescope perfectly collimated. Link to comment Share on other sites More sharing options...
Orion Posted February 12, 2015 Share Posted February 12, 2015 (edited) When I first got my NR in 1982, I made what I thought was a mistake of trying to remove a tiny piece of grease from the primary. I picked most off manually, then used teased lens tissue dipped in distilled water, then lightly brushed the teased wetted paper over the small area. When it dried, I could see tiny sleak marks where I had probably grazed the surface. These could only be seen at a glancing angle, but other angles, I couldn't see any mark at all on the shiny surface. I worried I might have ruined the mirror, but not so. Some months or may be the year after, I looked at one of the two bright stars in Gemini with high power. One of them (I can't remember which) was, at that time, a closely spaced double star of about 2.8? arc sec. When I looked at it, it was a boiling turbulent silvery ball. I was disappointed and thought, ruined mirror. But I looked several other times and still, a single ball. Then on one night, using the same magnification, the star appeared as two stars just touching each other like a figure eight with a thin black line space in between them. I had resolved the binary. I think it had a period of twenty odd years and since then, they may have opened up more and easier to split (or closing again?). But at the time, they were close. Although the resolving power of an 8" is, I think about 0.5-1 arc second, I was pleased that the binary had been resolved. There are more testing closer binaries, but this was enough for me. Have a go at that star (it's either Castor or Pollux). Edited February 12, 2015 by Orion Link to comment Share on other sites More sharing options...
philjay Posted February 12, 2015 Share Posted February 12, 2015 Having a look at astrobaby collimation guide came across this, a near on perfect example of what I was seeing when I did star test just off focus, except without the rings, maybe answers my query ? Erm, there are rings easily visible in that image so if yours is the same you have nothing to worry about Link to comment Share on other sites More sharing options...
Guest zidder Posted February 12, 2015 Share Posted February 12, 2015 I have seen the double in castor Link to comment Share on other sites More sharing options...
Tweedledee Posted February 12, 2015 Share Posted February 12, 2015 That is a nice double star to split Gary Actually it is a six star system, but you'll only see 3 of them in a telescope... http://astrobob.areavoices.com/2012/02/05/meet-castor-a-remarkable-double-double-double-star/ Orion 1 Link to comment Share on other sites More sharing options...
Guest zidder Posted February 12, 2015 Share Posted February 12, 2015 Erm, there are rings easily visible in that image so if yours is the same you have nothing to worry about Mine doesn't have the rings just the star burst effect Link to comment Share on other sites More sharing options...
Orion Posted February 12, 2015 Share Posted February 12, 2015 That is a nice double star to split Gary Actually it is a six star system, but you'll only see 3 of them in a telescope... http://astrobob.areavoices.com/2012/02/05/meet-castor-a-remarkable-double-double-double-star/ A very interesting read on that sextuple star Pete. I didn't know that. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now