So EPs are confusing (at least to me...)

[Nystra]

Hoping someone can help please. I have read a lot of the posts about eps but still find it confusing.

I have a Skywatcher explorer 150P, which came with a 25mm, 10mm and a x2 Barlow.

I am not sure if I should be replacing the ones that came with my scope or buying additional ones or...? There seem to be many recommendations to buy BST, but what size?

Any advice gratefully received.

[Thirdway]

Yes, I'm a noob too and it can be confusing. Particularly the sheer number and price range. There is a lot of playing around to do before choosing any additional EPs. Get some practice using the scope, the 25mm is pretty good and can easily pick up DSO such as the Orion Nebula. The 10mm isn't great, but it will still produce worthwhile images.

Once you have some idea of what you want to improve on then it's worth making some purchases. It's often recommended that you join an astro club and get some advice at Star Party events where you can test different EPs.

It's taken me 4 weeks to get an idea. As you are probably itching for recommendations, after talking to a few people I decided to get an 8-24mm Baader Click Zoom and a Skywatcher Panaview 32mm. That gives me something better than the standard EPs right down to 8mm and then a nice wide view for DSO and general searching with the 32mm. That's not to say these are right for you, just my choice. I will probably get a couple of Celestron xCel lx in 8mm and 18mm for less than ideal viewing conditions and for close planetary viewing.

[Grunthos]

The ones that came with your scope are fine (as is the barlow).

Kick back and enjoy your new toy (aka scientific instrument:D).

Once you're familiar and comfortable with your new baby you may (only may!) wish to obtain a few accessories for it - of which EPs are only one possible suggestion.

A good star chart, warm clothes, something to collimate with might be options you wish to investigate first.

Don't feel pressurised into buying "kit".

Have fun!

HTH

[imarcs]

Read this before buying anything. It helped my understanding immensely

http://stargazerslounge.com/beginners-help-advice/80772-eyepieces-very-least-you-need.html

[John]

The range of eyepieces available today is confusing. If you have not already done so, it's well worth reading through this primer as a starting point:

http://stargazerslounge.com/beginners-help-advice/80772-eyepieces-very-least-you-need.html

The other shock is that buying the scope is the cheap bit ! - it's ever so easy to spend as much as the scope costs on accessories so it's worth getting used to using the scope with the standard ones so that your later spending decisions are sound and suit your preferences.

Edit: Marc got there 1st with the link !

[Nystra]

Thanks for all the advice. I will stick with what I have for the time being and get used to those first.

[brantuk]

Might be a good idea to join an astro soc or an observing group. You'll find most folks are friendly and happy to let you try some of their eyepieces in your scope. So you can easilly find what suits you best

[Catweazel]

Some great advice there guys! I think that the astro club idea is a good one, as the best way to assess which EP's will suit you is to try them. For example, I tried a BST 8mm, which are highly recommended, but didn't get on with it, and replaced it with a TBM II, which I find much better. So being able to try EP's out is ideal if you can. After buing my scope, the first EP I replaced was the SW 10mm, and the replacement, a Meade 4000, is a definate improvement (cost me £15, second hand).

[archway69]

I had this same problem last year when i bought a new scope and i went for the Meade set Meade 5 Piece MA Eyepiece Set

I have found it to be an excellent choice

[umadog]

About eyepiece prices: the expensive ones tend to be those that offer wide apparent fields of view. These are expensive because they require rare, high index, glass for their manufacture. In addition, they require more elements than more simple designs. Since light is being bent at large angles it becomes important that they are well designed and accurately built. If they're not, you will get nasty distortions at the edges of the field of view. So when you're paying a lot of money, that's what it's for. Even within this category of ocular, however, there are some good deals.

There are plenty of good quality cheaper eyepieces. Usually these are Plossls. They are cheaper because they have fewer elements made of non-fancy glass (which would be unnecessary for the design). A good Plossl will have a sharp field of view to the edge and provide you with a decent 50 degree apparent field of view. This isn't huge by modern standards but it's quite acceptable, particularly for planets.

Field of view isn't the only criterion of interest. Another is eye relief. Usually eyepiece with fields over 80 degrees tend to have slightly tighter eye relief. A lot of people find fields over 80 degrees to be unnecessary and would rather have a 60 to 70 degree field with better eye relief.

[Capricorn]

Eyepieces are confusing partially becasue of the choice. One reason I like the BST's is because they make 6 in the complete set and that is it.

If you have the f/7.8 150P then the 8mm BST will give about 140x and good results.

In the future you may decide on the 5mm and if it is OK that is as small as I would suggest considering for the f/7.8 scope.

The 12mm will give good medium magnification views and the 25mm, will be OK for wide views.

That is 4 of the 6, if you decide to complete the set then that is your choice.

The "lack" of focal lengths is useful, I have 4mm, 5mm and 6mm plossl's. They may be cheaper but after buying the 3 I have spent more then one BST, which is much better, and in the past I have ended up swapping eyepieces in and out.

Now if the 5mm BST is no use then the 8mm goes in and I forget the 5mm all together. If the 5mm is good then yippee.

You could get the TMB's, close to the BST's in overall performance but then you are faced with a 4mm, 5mm, 6mm, 7mm and more to choose from. Sounds nice to have the choice but to find out the one for any particular evening you could need 3 and that means buying them = costly.

With the BST's you cannot debate buying the 4mm, 5mm or 6mm. You only have the 5mm to choose from.

[FOYS]

I was in the same shoes as you last week and I plumped for a 8mm BST.

I couldn't be more happy with it. Tried it with the barlow that came with the 150p when looking at Jupiter and it wasn't over magnified like I feared it would be, just about managed to focus it.

[Nystra]

Many thanks for all the advice everyone.

[todd8137]

hi there yes its a mine field all i can say is try and get the use of a eye piece before you buy if you can ask others i have brought high end eye pieces 2" ones just to find the coma and all the rest that bad i sent them back so choose wisely

[umadog]

hi there yes its a mine field all i can say is try and get the use of a eye piece before you buy if you can ask others i have brought high end eye pieces 2" ones just to find the coma and all the rest that bad i sent them back so choose wisely

Coma? Well that's not surprising since coma is a product of the mirror not the eyepiece. You won't get rid of coma with any eyepiece: you need a coma-corrector for that. What a good eyepiece will do is get rid of astigmatism (which can look like coma). It is true, though, that some expensive eyepieces out there are astigmatic with faster scopes. It's important to make sure that you're buying an eyepiece which will perform well at your focal ratio.