What kind of lens should I use to make a Galilean telescope an astronomical telescope will be better?


Posted November 4th, 2010 by admin 1 Comment »
telescope
Siddharth asked:


I like the Universe, but i have no telescope. They are not available in our area. So, i decided to make it on my own. Help me for galilean or astronomical telescope
What type of lens for objective and eyepiece?

How to fix my finderscope on my telescope?


Posted March 7th, 2010 by admin 5 Comments »
telescope
TheOriginalSara asked:


Whatever I see through the finderscope is not what the telescope sees :( It seems to be some distance off because after searching for a while through the eyepiece I see the object not far off from where the finderscope thought it was, but it takes a very long time and is very inconvenient.
It’s a reflector telescope. If anyone knows how to fix this please explain in simple language :D thanks!

How does a newtonian reflecting telescope work?


Posted February 1st, 2010 by admin 3 Comments »
telescope
Betafett asked:


My new telescope has piqued my curiosity–More specifically, why is it that when looking into the eyepiece we don’t see the cross shaped mount for the diagonal mirror (or the mirror itself?) in the image? I can’t get my head around the problem and it’s been so long since I did optic physics that I’ve pretty much forgot how it all worked….

How does a telescope work different from a camera lense?


Posted August 17th, 2009 by admin 2 Comments »
telescope
water_skipper asked:


How does a telescope work different from a camera lense? I’m specifically wondering about magnification. With a camera lense, a longer lense means higher magnification so to get really high magnification it needs a really long lense. With a telescope they just change the eyepiece to get higher magnification and don’t change the length of the telescope.. How is it telescopes can change magnification like that and camera lenses can’t?

How to see through a telescope?


Posted August 9th, 2009 by admin 3 Comments »
telescope
meena g asked:


I recently bought a Field&Stream model #HEH00251. I want to know whether it is a refraction or a reflection telescope. And I also want to know which eyepiece to buy to see celestial bodies.

How do I determine my Telescope’s Focal Length?


Posted July 23rd, 2009 by admin 3 Comments »
telescope
nymets6159 asked:


Well I really don’t exactly know what telescope I have, I know it’s a Meade telescope, but I don’t know the model. But, anyways, how would I find out the telescope’s focal length? Please I need this to check my eyepiece magnifications.

A telescope with 20cm primary mirror has f# of 5. What focal length of the eyepiece to get 100x magnification?


Posted May 31st, 2009 by admin 2 Comments »
telescope
:3 asked:


A telescope with a 20 cm primary mirror has an f# of 5. What would be the focal length of the eyepiece required to give a magnification of 100? I know there’s an equation, but I don’t know what it is. Thanks in advance.

What is wrong with my telescope? I see a reflection of my own eye when I look into the eyepiece?


Posted March 23rd, 2009 by admin 1 Comment »
telescope
Brenda P asked:


I have a used Meade telescope (not electric other than Starfinder); I can see the moon, but have to look “around” the mirror - a reflection of my eye and the eyepiece itself covers up the middle of my field of vision. I put my hand inside the tube, and the mirror does not appear to be moveable.

How important are precision optics in a home-built Dobsonian telescope?


Posted March 6th, 2009 by admin 3 Comments »
telescope
mvsopen asked:


I’m going to be building a 12.5″ Dobsonian telescope. For the primary mirror, precision optics, of F5 or better and certified, are roughly $1600. Yet many websites sell Chinese imported mirrors, at prices between $500 and $800. Will the quality of the primary make a huge amount of difference in the finished product, or would investing in a better eyepiece yield the same results?

Where can I buy a device to convert my camera’s telephoto lens into a telescope, and how much would it cost?


Posted February 8th, 2009 by admin 2 Comments »
telescope
Deborah asked:


I have several telephoto lenses (with the old screw thread fitting) which I don’t use much on my camera. I know it is possible to get an eyepiece to fit on to the back of the lens, to turn it into a high quality telescope.
Does anyone know where I can buy this device in the UK, and how much would it cost?
If I used such a device with a 135mm lens, what magnification would it give me when operating as a telescope?