Help needed on what lens etc to get

[Kepler22]

Just managed 5 minutes viewing tonight on my daughters new 150P Dob. from First Light Optics. Comes with 10mm and 25mm eyepieces. Managed to see Jupiter and four moons (looked quite small). What lenses/Barlow do you recommend that I buy as accessories. Interested in looking at DSO if possible, budget probably around £50. Now waiting patiently for skies to clear, but what a great start. Thanks everyone for recommending this scope!

[Dellis]

Have a look here, that should set you off in the right direction.

Dave

[ronin]

Assuming that the scope is f/5 that makes a 750mm focal length.

Going to follow old advice and suggest the BST Explorers from Sky's the Limit. £41 a piece.

They come in 5mm and 8mm focal lengths, also 12mm, 15mm, 18mm and 25mm.

The 5mm will give 150x good for Jupiter but as magnification goes up the field of view goes down, so you have to nudge the scope more often to follow. The BST's have a wider field of view which helps.

The 8mm will give 94x, still good for Jupiter. However when Saturn comes up you may need more.

"Only" problem with BST's is that they don't have more focal lengths, as in a 6mm and a 4mm.

For DSO's I would think that the 5mm may produce too dim an image so the 8mm would be better for that.

Alternatives are TMB planetary's, they come in a greater selection of focal lengths. However if you get below 5mm you may find more and more problems creep in.

You will find that a 1mm differnce in eyepiece focal length can make a fair difference.

[Chris H]

It's the 150p Dob so its F7.84. I'd stick with the ep's you have for the mo, the 25mm will be just fine for DSO's and the 10mm will be ok for planets and closer views of DSO's. Play with them for a while learn how to use the scope and what you want to view and then dip your toes into the sea of eyepieces, careful it's deep.

[DOBBY]

Hi Keplar.. a cheap barlow for £30 - £40 will double your options for now... but, as Kris says... have a good play around with your 'scope...then decide on additional eyepieces...don't forget to look for used eyepieces - bargains to be had from peeps who bought in haste

[ronin]

If it is F7.84 then easier, forget a 5mm, get the 12mm (98x) and at some time the 8mm (147x), or the other way round.

Since the 10mm would have given 117x that should have been more then enough to see Jupiter so was there a problem?

[Kepler22]

Thanks everyone for your replies, very helpful. I suppose the image was smaller than expected.

I may go for a Tal x2 Barlow for the time being, until we get used to the scope. I like the idea later of a 8mm ep, then maybe add a 15mm or 25mm later for DSO. Reading through previous posts BST get lots of recommendations. Have also looked a SW SP Plossi ep and these might be worth considering. Does anyone have a view on these as opposed to BST. Cheers.

[John]

I think the BST Explorers are an improvement on the standard eyepieces supplied with the scope and a little better than something like the Skywatcher Plossl. They are more comfortable to view though than plossls and provide a slightly wider field of view both of which are nice features.

The issue of "the image was smaller than expected" is a very common one expressed by newcomers to observing. I think it's because we all get sub-consciously "conditioned" by the images we see posted in magazines and on the net. Visual astronomy is, with one or two exceptions, a much more subtle experience

[Kepler22]

Thanks John, I thought that was the case on the image. Being new its difficult to know what you "are" seeing is what you should be seeing.

I think I should get used to the scope initially before getting ep's, but I don't suppose it will be long before I dip my toe in and will probably go for three, 8mm, (that would give the maximum magnification with the x2 Barlow), 15mm and 25 or 30mm.

Jon

[Kepler22]

The more posts I read the more questions it raises!

If I get the x2 Barlow, and then subsequently get a 8mm BST Explorer, does that take the magnification at 300x to high to be useable for planetary observation in the UK. Would a better option perhaps be to buy a 6mm Baader Ortho, which would give a 200x mag. and do without a Barlow? Reading the post on how to calculate the max. mag, 6mm is perhaps the highest for this 150P Dob. (i.e. 2/3rds max mag.) Price wise there is not much difference. Also how would the field of view compare. Perhaps later invest in the BST 15mm and 25mm?

Would appreciate your views.

[John]

You might be able to use 300x a couple of times a year, maybe. 150x - 220x is my staple high power range for all my scopes. An Ortho will have a field of view 28% smaller than a BST Explorer and much, much tighter eye relief. The ortho's views will be a little sharper and more contrasty though. It's all about trade offs - which ones to make is a personal decision probably.

[faulksy]

as john said the bsts are great from alun at skys the limit they will let you trial a few eps first before you buy as well

[NickK]

Although more than your budget - Baader Hyperion are on the sweet spot of cost & returns.

The good thing about eyepieces are that they can be traded/sold or carried over to the next scope