low power eyepiece advice

[Cloudycat]

Hi everyone, I'm hopng someone could help advise me about a low power eyepiece.

I have a Sky-Watcher 150PL EQ2/3, it came with a 25mm wide angle, 10mm and 2x Barlow lens - I assume these are standard and I have no complaints as I'm new to this and don't know any better.

I'm in no rush but I would like a lower power eyepiece with as wide a view as possible, I think this would mean a 32mm although I notice there are 40mm available.

They would be 1.25", I should mention.

I'm also on a tight budget (after splashing out the extra on the 150 rather than the 130mm telescope), but only want something that's worthwhile.

Do you think the Sky-watcher SP series are any good or would it be worth stretching to something that costs a little more.

Come to think of it - will I notice much difference between the 25mm and a 32mm (or 40mm)?

My scope is f8 and before buying I remember reading that a longer focal ratio is more forgiving on lower quality eyepieces (I don't understand how this works though).

Thanks in advance

Coming soon: High power eyepiece advice, please!

Ian

[Moonshane]

a 32mm plossl shows the same field as a 40mm plossl but with a darker sky background. although a little more expensive that the competition, for me the best value 32mm plossl is the Televue. Used they are £60-70 and you'll never need another even if you get a faster scope. It's superb. You can buy e.g. a Omni version or other Chinese brands which will be good in your scope for a little less but I'd just save a bit longer and pounce on a TV when one surfaces used.

[ismangil]

The widest view on a 1.25" would be with a 24mm 68 deg such as Hyperions, they would be £60-70 or so second hand.

[CSM]

Another vote for the 32mm Televue Plossl - always the first one I use.

[John]

24mm / 68 degree, 32mm / 52 degree and 40mm / 43 degree eyepieces all show pretty much the same amount of sky but with increasing magnification as the focal length gets shorter. The 43 degrees of the 40mm looks a bit "tunnel like" to me so my preference is always the 32mm plossl or 24mm wide angle.

[ismangil]

24mm / 68 degree, 32mm / 52 degree and 40mm / 43 degree eyepieces all show pretty much the same amount of sky but with increasing magnification as the focal length gets shorter. The 43 degrees of the 40mm looks a bit "tunnel like" to me so my preference is always the 32mm plossl or 24mm wide angle.

And my experience is higher magnification for my light polluted backyard skies are better, as it darkens the sky, making the object easier to see.

Which is why I have gone wide angle crazy :-)

[John]

And my experience is higher magnification for my light polluted backyard skies are better, as it darkens the sky, making the object easier to see......

I've found that as well. It's really quite noticeable on some nights.

[chiltonstar]

And my experience is higher magnification for my light polluted backyard skies are better, as it darkens the sky, making the object easier to see.

Which is why I have gone wide angle crazy :-)

....and presumably darkens extended DSOs as well?

Chris

[Cloudycat]

Thanks everyone so far but it's getting a bit technical for this newie.

John - would a 32mm plossl show more sky than my Super 25 Wide Angle that came with the scope?

I'll rule out the 40mm.

Ismangil - my backyard suffers from light pollution too, if higher manification = better contrast then am I better sticking with what I've got?

I was hoping I could get something the scale of the Pleiades in full view, or is that hoping for a bit much?

As I said - no rush, I would just like to use what I've got for the time being while I get more experience.

Ian

[John]

....and presumably darkens extended DSOs as well?

Chris

No - it makes their contrast stand out more against the darker background sky. Thats one of the advantages of wide field eyepieces.

[ismangil]

Thanks everyone so far but it's getting a bit technical for this newie.

Ismangil - my backyard suffers from light pollution too, if higher manification = better contrast then am I better sticking with what I've got?

I was hoping I could get something the scale of the Pleiades in full view, or is that hoping for a bit much?

Ian

Plossls are cheap enough, you can try 32mm and see whether the wider view is worth the slight brightening. For bright clusters I suppose it's not too much a problem.

Pleiades for me is a binocular object

[John]

Yes, a 32mm plossl will show you a true field of view of 2.25 degrees at 23x wheras the 25mm standard issue "super wide" shows 1.66 degrees at 30x. That's quite a lot more sky. The optical quality of the plossl will be somewhat better than the 25mm too - they are only basic eyepieces to get you started to be honest. And they are not really "super wide" either !

The alternative would be to save up more for a proper 24mm wide angle eyepiece but it will cost a lot more than a 32mm plossl would to work well with your F/5 scope.

As Perry says, 32mm plossls don't cost a lot, work pretty well in most scopes and I reckon are a "low risk" purchase

[Moonshane]

hi John

I think it's a PL so 1200mm focal length and f8? therefore 1.3 degrees at 38x with 32mm Plossl vs 48x and 1 degree with the 25mm - still a jump but the advantage of f8 is a 4mm exit pupil with the 32mm.

[John]

hi John

I think it's a PL so 1200mm focal length and f8? therefore 1.3 degrees at 38x with 32mm Plossl vs 48x and 1 degree with the 25mm - still a jump but the advantage of f8 is a 4mm exit pupil with the 32mm.

Thanks for that clarity Shane and sorry for any confusion Ian - there was I thinking the scope was the F/5 version

[alan potts]

I to would go for a Televue 32mm Plossl, yes more expensive than others but better than others. You will always be able to sell it to, if you buy secondhand you will not loose either, they hold their money.

Alan.

[Cloudycat]

Televue 32mm Plossl seems to coming out tops at the moment, I think I might save a bit more.

Ismangils suggestion of a 24mm 68 degree Hyperion is interesting, though.

Thanks to everyone for the advice - especially John, Ismangil and Moonshane for coming back more than once to this post.

Ian

[Moonshane]

one option is join the Liverpool Astro society sometime. I bet there would be some good choices of eyepieces there and people usually don't mind the odd loan if you take your scope.

[Lorne]

one option is join the Liverpool Astro society sometime. I bet there would be some good choices of eyepieces there and people usually don't mind the odd loan if you take your scope.

Totally agree with this, getting a look through some of my local groups EP's in my scope helped me decide on my choice.

[Cloudycat]

one option is join the Liverpool Astro society sometime. I bet there would be some good choices of eyepieces there and people usually don't mind the odd loan if you take your scope.

Hoping to get down to Pex Hill sometime soon to take a look and say hello.