Orpington Astronomical Society

Astronomy => Telescopes Etcetera.... => Topic started by: von on Apr 27, 2005, 04:32:00

Title: Getting there!!
Post by: von on Apr 27, 2005, 04:32:00
Hi all,
      the 5 inch dob is getting there,the spider,focuser,mirror cell and mount are built.The mirrors are on the way from India{i think these will be very good},Shame i cant post pics i have a cam but dont know how to.My little girl is having great fun epoxying her hair to the base{dont tell the wife}.I do have a couple of questions to ask,Rick you sugested a 18mm eyepiece but what type do you guys use.I would love a top of the range one but will have to go for one in the 20 quid range good second hand is ok.Im having enough problems with making the scope i dont need another problem like type of eyepiece so what you guys say il get.Second question is inside the tube,Baffels, chips of plastic, velvet.Do you need a rough surface inside?if so will flock wallpaper srayed flat back work as i have this?
Thanks in advance.
Title: Getting there!!
Post by: Rick on Apr 27, 2005, 19:25:00
Plossols seem to be the favorites these days, but mine are all Orthoscopics, and I've been happy with them.
Title: Getting there!!
Post by: Rick on Apr 27, 2005, 19:26:00
Oh, and a matt-black paint inside the tube will probably be best...
Title: Getting there!!
Post by: Rick on Apr 27, 2005, 19:33:00
...but the flock wallpaper is probably overkill. :wink:
Title: Getting there!!
Post by: Anonymous on Apr 28, 2005, 22:07:00
Hi all,Thanks for the replies Rick.Overkill on the inside of the tube!Well im bound to be wrong but my thinking is as if only got a 125mm primary mirror very small in todays world. I thought that all the attention to detail would make a very small difference to the telescopes performance.Also i got a footpath light 7 meters from my garden {getting on to the the council about this matter}.Just a quick question how do i post pictures of the scope on the forum??
Thanks in advance.
Title: Getting there!!
Post by: Ian on Apr 28, 2005, 22:48:00
Hi Von.
To post images, you need to host the image somewhere else (you may have webspace as part of your package from the ISP) and use BBcode to refer to it in your message. Take a look in the FAQ (menu, top right hand corner) regarding how to use BBCode.
Title: Getting there!!
Post by: Rick on Apr 29, 2005, 06:42:00
The usual approach to telescope tubes is to have baffles at intervals on the inside, and to have everything inside the tube apart from the optics matt-black. The baffles shouldn't get anywhere near the optical path, but are intended to block stray light entering off-axis. The matt-black paint should prevent any reflections off the inside of the tube.
Title: Getting there!!
Post by: von on Apr 30, 2005, 01:08:00
Hi all,My son is trying to sort out a website to post our pics.Talking about the inside of the tube, will flock wallpaper glued inside and painted with blackboard paint work just as well as just painting the inside?my reasons for flock are that every strand is irregular so should stop all unwanted light.
Title: Getting there!!
Post by: Rick on Apr 30, 2005, 02:09:00
If the black paint really is matt then it shouldn't make a noticable difference. If the paint produces a slightly shiny surface then it might help.