some advice on lenses

[denisorionxt6]

So Ive got a brand new orion skywatcher xt6 with the standard lens that it comes with, Ive had a good view of jupiter earlier this eve, am thinking of buying a  barlow lens x2 or x3? Im very new to all this stuff so maybe you could advise me which lens or lenses to buy? should I get a few different ones or just the extra barlow and what magnifiaction(s) should I get

[knobby]

Not sure what ep comes with the Orion but I think its a 25mm, if that is correct then if you are into planetary veiwing maybe try a 12 or 15 mm BST star guider, about £45

[NGC 1502]

Tough question actually.......

Wondering what your budget is ?    There's such a huge range of eyepieces at all prices.

However, what I'd do is this - have at least a few sessions with your new telescope, see how you get on.  You've looked at Jupiter, that's a great test of how good your current equipment is.  

How was the view ? After the scope cooled to ambient temperature, with Jupiter well clear of the horizon, could you see a sharp disc with more than two cloud bands ?  What magnification were you using ?

It may take several sessions to determine this, the steadiness of the atmosphere varies a lot from night to night.  If you were getting a good view (as already described) at 120 - 150x, that's good.  If you are getting a sharp view at 150 - 200x, that's excellent.

When buying eyepieces, I'd avoid the cheapest, more expensive in the long run if you have to upgrade again.  Get the best you can, but be satisfied with not super high powers. Above 200x is used the least.

HTH, Ed.

[knobby]

Sorry just realised you asked what mag you'd get... Mag is scope length / ep size so if your scope is 1200 mm the 25 mm supplied will give 48 x whereas a 12 mm will up that to 100 x

[ronin]

As the focal length is 1200mm then I suggest a 12mm for 100x and an 8mm for 150x, I think Orion supply a 25mm giving 48x. That should be usable for the majority of things. At some time look at a 32mm (36x) for wider views.

Choice, the BST Strarguiders from Sky's the Limit will be good, for a bit less StL also do a BST Wide angle, oddly named as it is not as wide (quite) as the Starguiders.

[denisorionxt6]

thanks for all your replies, I can use the info to make up my mind on what to buy. My budget fluctuates as self employed working outdoors and rain etc affects my work (and my star gazing as I noticed tonight with clouds and wind). Ill try and make sure I only buy decent ones though even if I have to wait longer to afford them as I want to make the most out of my scope, I love the thing already!

my view of jupiter was fairly sharp earliier SB, think I could see about 4 bands of colour maybe? I tried to zoom right in but I ended up seeing the spider vein thing that holds the secondary mirror? dont know if thats normal... 

I did think at the time of my clearest view of jupiter that maybe if I get a barlow lens it would be clearer which inspired me to ask on here The scope hadnt had time to cool down properly to be honest as it was really warm indoors and fairly cold outside, so it probably would have helped if the sky had stayed clear for long enough for the scope to equalize to give me better views?

[astronymonkey]

Hi,

it sounds as if you adjusted the focusser rather than zoon in as this would show the shape of the secondary spider overlaid on the out of focus star. You would need to change eyepieces to increase the magnification.

glad you enjoy your new scope and remeber any eye pieces you get can be used in an different scope if you ever decide to trade up.

cheers

[denisorionxt6]

Hi,

it sounds as if you adjusted the focusser rather than zoon in as this would show the shape of the secondary spider overlaid on the out of focus star. You would need to change eyepieces to increase the magnification.

glad you enjoy your new scope and remeber any eye pieces you get can be used in an different scope if you ever decide to trade up.

cheers

Im probably being very thick here but how do you mean adjust focuser rather than zoom in, as far as I can see I only have one way of adjustment which is the rack and pinion zoom in zoom out of the eye piece?

[astronymonkey]

Hi,

thats the focusser, its doesn't zoom in any way.

Zooms increase the magnification and is a feature on only a handful of eyepieces, but the bit you refer to is only used to bring a chosen eyepiecen into focus and this will need adjusting slightly if a different eyepiece is used.

when the focusser is adjusted it has the effect of making a star look bigger yet all that is really happening is the star has gone out of focus.

cheers

[denisorionxt6]

I understand now thanks for explaining Astro. Do feel a bit silly now lol. Cheers to all and hope your xmas's were good ones glad I found this forum

[astronymonkey]

No need to feel silly, this forum is great for being able to ask questions and discuss ideas etc without feeling daft. Even members with thousands of posts and those that have been doing the hobby for years still have queries which often have pretty simple solutions.

Your post reminded me of when I got my first telescope nearly 30 years ago and a friend thought it was great because it made the stars look as big as the moon ..... I only realised what they were talking about when I had a look and realised that they were looking at an out of focus star.

what telescopes do it increase the amount of light that gets into your eye, as you know your pupil get bigger in the dark to get more light in but it can only get to about 6-7mm. so stick a telescope in front of your eye with a 6inch aperture and you are now seeing what you would see with a 6inch pupil albeit magnified somehwat.

increasing magnification makes objects like nebula and planets look bigger but the stars should always look like pin points of light when they are in focus.

cheers

cheers

[denisorionxt6]

Thank you

[ScottS]

The Starguiders are very good value for money.

[knobby]

Thank you