Finderscope frustration!

[crazyjedi]

The moon is a fast moving target (relatively speaking) and large making accurate alignment difficult. Any star in the sky is better than the moon as they all move much more slowly and are pin points. if you line the moon up in your scope, by the time you've centred your finder the moons centre will have moved from the middle of you're scopes fov.

The best method for aligning your finder is to use a fixed terrestrial object as far away as possible. This is because it does not move relative to your scope. If this is not possible use a star. The best star is Polaris as it's movement is tiny relative to the earth, so much so that it is not detectable for the time it takes to set up your scope (even if you're slow like me) it's movement is only notable over many years. If you can't find Polaris any star is better than the moon.PS planets are also bad objects to align your finder with as they also move quickly relative to you're scope.

Hope this helps cure some frustration , :-)

[gkec]

Those were the Galilean moons. You have met Callisto, Ganymede, Io and Europa, lovely but shy ladies. Their other 60+ sisters are very shy and seldom seen from down here.

I think Ganymede is a bloke!

[gkec]

The moon is a fast moving target (relatively speaking) and large making accurate alignment difficult. Any star in the sky is better than the moon as they all move much more slowly and are pin points. if you line the moon up in your scope, by the time you've centred your finder the moons centre will have moved from the middle of you're scopes fov.

The best method for aligning your finder is to use a fixed terrestrial object as far away as possible. This is because it does not move relative to your scope. If this is not possible use a star. The best star is Polaris as it's movement is tiny relative to the earth, so much so that it is not detectable for the time it takes to set up your scope (even if you're slow like me) it's movement is only notable over many years. If you can't find Polaris any star is better than the moon.PS planets are also bad objects to align your finder with as they also move quickly relative to you're scope.

Hope this helps cure some frustration , :-)

I don't think they move that much during an alignment session.

[nicks90]

depends how quickly you can set the finder!

I'm lucky in that I have a power pylon about 1km away which is perfect for setting up the finder accurately.

[astrofox]

When adjusting the finder in daylight remember that unless the target is a long way away then parralax errors will creep in and throw the allignment out at infinity. Use the daylight setting as a guide, then finally tweek on a star

[crazyjedi]

I don't think they move that much during an alignment session.

The Moon is one of the fastest moving astronmical targets in the sky barring man made satellites. I find it too fast moving for accurate alignment. The planets zip along quite quickly too.

When adjusting the finder in daylight remember that unless the target is a long way away then parralax errors will creep in and throw the allignment out at infinity. Use the daylight setting as a guide, then finally tweek on a star

Good point

[majapala]

Every time I read a thread here I learn something new, even if it means I'll probably end up spending money (this time on a Telrad). Also, I finally know what that rubber band is there for!

[crazyjedi]

Every time I read a thread here I learn something new, even if it means I'll probably end up spending money (this time on a Telrad). Also, I finally know what that rubber band is there for!

Me too! I think the spending money bit is endemic to astronomy. It seems to get worse the longer you stay in the hobby and the more you spend the more you want

[badgerchap]

When I was using my Dob I found the finder so hopeless that I was just hunting around with the main scope to find what I wanted. Now on my Newt I have a nice, big, easily adjustable finder and it makes all the difference!

[crazyjedi]

A poor finder can be extremely frustrating. A good one is a very useful tool!

[glowjet]

Focusing on distant objects in daylight brings to mind an amusing incident. Attending an annual traditional long bow tournament many years ago, it was normal practise to sight your bow in on a distant object, there was a hillside at the rear of the targets and the bespectacled archer next to me kept missing the target every few arrows, it turned out that the brown blob in the middle of the distant hillside that he used as a reference point was an old grazing horse, slowly munching its way across the field. Sorry to go off topic but the moral of the story is focus on something as far away as possible but make sure it is stationary, for night-time Polaris is as good as it gets as has been mentioned

John.

[crazyjedi]

Focusing on distant objects in daylight brings to mind an amusing incident. Attending an annual traditional long bow tournament many years ago, it was normal practise to sight your bow in on a distant object, there was a hillside at the rear of the targets and the bespectacled archer next to me kept missing the target every few arrows, it turned out that the brown blob in the middle of the distant hillside that he used as a reference point was an old grazing horse, slowly munching its way across the field. Sorry to go off topic but the moral of the story is focus on something as far away as possible but make sure it is stationary, for night-time Polaris is as good as it gets as has been mentioned

John.

Ha ha - I did exactly the same thing some years ago when trying to focus my finder when in Wales. Unforunatly the pale rock I was focusing on upon a far off hillside was, under closer focusing was indeed.......... a sheep . I didn't notice at first as it had it's back to me and was a long way off. When I tried to fine focus by popping in a high powered lens it turned side on and I swear - looked at me. I nearly fell over laughing