Am I doing something wrong?

[howardmcheng]

I bought myself a 70mm refractor telescope this week, and got it out the box today, aligned the viewfinder and set it up on my Tripod. But am I doing something wrong?

I was trying to look at the Great Orion Nebula tonight, and I found where it "should be", but all I saw was a lighter wispy area in the sky (maybe very slightly greenish too), as opposed to what I expected the nebula to look like.

I was wondering if this means that I need a bigger scope, or do I just need to head out of town. Hardly any light hits my garden from where I was viewing, although nonetheless, it is still in the middle of town.

Am I doing something completely wrong (like actually looking at the wrong place?), or is this to do with needing a bigger scope/being out of town.

Any thoughts would be much appreciated. Thanks in advance.

H

[thing]

You're not doing anything wrong Howard, it looks like a grey/green wisp to all of us. Your eye is a poor detector of colour in low light, don't forget that the brilliant images you see of M42 are the results of long exposures stacked together, something way beyond the capability of the eye. Which is one of the reasons folk do imaging, it reveals things that the eye simply can't see.

[steppenwolf]

I'm with Dave, Howard, by your description, you found it just fine and there is not much to add to Dave's explanation except to ensure that you let your eyes get properly dark adapted by keeping away from any lights for as long as possible before you start your viewing session in earnest and then get comfortable and spend some time on the same object as the more you look at it, the more you will see.

[adamsp123]

Agree with the other guys, make sure you got the scope focused spot on, your eyes are night adjusted and then observe the longer you look the more you will see, but glorious colour afraid not.

[howardmcheng]

Thanks for the replies guys - at least I know that I might not be completely hopeless at telescope astronomy lol

Cheers!

H

[Doc]

Also remember you are looking through just 70mm of aperture. The more aperture the more you will see. Those little green wisps will get alot bigger and brighter.

[howardmcheng]

LOL Mick! Thanks for reminding me of that! Although like people have said, one small step at a time. I can find my way around the sky with the naked eye, but this is my very first telescope (CANNOT believe I only have JUST bought one!), so give me a bit of time to practise losing massive field of vision but still finding things.

I got a quote through the other day for a 6inch mirror with a focal length of 1000mm, so at the moment, trying to budget and draw up plans to see if it is economically viable to make my own Newtonian reflector or just buy one.

I have alternatively toyed with the idea of making a reflector with lots of tiny normal straight mirrors which will act as the one concave mirror, but we shall see.

Still, going to concentrate on close up Lunar and a bit of planetary work. I think with Saturn being 1-2 degrees side on in the coming month, the Saturnian moons should be out to play quite nicely.

H

[scotastro]

Building your own 6" reflector will not be cheaper than a factory build one like Skywatcher, but you will be able you have better quality optics (not knocking SW they are good for the money) and your scope will have the type of focuser, finder, etc. you want. A long focal length f6 or f8 would be best for planetary work.

Mike

[John]

..... but you will be able you have better quality optics (not knocking SW they are good for the money) .....

But perhaps not if you pursue the idea of "making a reflector with lots of tiny normal straight mirrors which will act as the one concave mirror"

Mirrors need to be parabolic in figure, not just concave.

John

[proflight2000]

One easy way as well is that when you look through a viewfinder to locate an object youd tend to close one eye. Try and get used to viewing with both eyes open, it seems a bit odd and first, but if you are trying to locate something through the viewfinder, the open eye makes it far easier to see your position across the whole area rather than the one eye option where you are very close in and cannot define a particular area. It works for me anyway.

[ianmwatson]

Mirrors need to be parabolic in figure, not just concave.

I think you can get away with spherical actually, if the scope is very slow F10 or more.

[The Warthog]

You can get away with a spherical mirror, but why would you, when even a slow scope will perform better with a parabolic mirror? You can buy a mirror kit, and grind a parabolic mirror, or buy a parabolic mirror, or just buy a telescope with a parabolic mirror and start looking through it right away.

The idea of many flat mirrors faking a parabolic mirror simply will not work, so forget it.

[ianmwatson]

You can get away with a spherical mirror, but why would you, when even a slow scope will perform better with a parabolic mirror? You can buy a mirror kit, and grind a parabolic mirror, or buy a parabolic mirror, or just buy a telescope with a parabolic mirror and start looking through it right away.

I seem to remember reading that a spherical mirror slower than F10 was diffraction limited, so would perform equal to a mass produced parabolic mirror. My point wasn't that I would or anyone should, it was that it could

[tinvek]

CANNOT believe I only have JUST bought one!

trust me soon you'll be looking back and saying that you cannot believe that you only bought just one

[howardmcheng]

LOL tinvek! I know what you mean - I'm already looking for another telescope! :oops: