Best EPs for Dob

[Mr Moonlight]

Hi,

What EPs would you recommend for a SW 10" Dob? I will purchase soon..

I understand that it will come with 2 EPs (10mm & 25mm), but which other ones would you recommend for DSO and planetary observation?

Thanks

[Orion_the_Hunter]

Hi, what's your budget? Do you wear glasses? Which is more important to you - Planets or DSO?

[Moonshane]

normally I'd suggest you use the ones with it for a while and maybe buy a barlow to get an idea of the range you normally prefer. assuming you have/ get a 2x barlow you will have 50x, 100x, 125x and 250x with the ones that come with it. I understand the 10mm that comes as standard is not usually too clever so maybe replace this first but there's no rush. take your time.

[Moonshane]

ps. I'd buy a Telrad as my first accessory if I were you.

[umadog]

I second the Telrad. It'll make finding stuff much easier.

Here's the deal: I believe your scope is F4.7, in which case a lot of cheaper eyepieces will not perform well. The short focal ratio tends to exacerbate problems in poorly made eyepieces. For instance, you would expect to see more astigmatism in the outer 1/3 or so of the field. This is in addition to coma, which you'll notice more at lower powers (i.e. above about 15 mm). Don't get overly concerned about this now, however. Take your time: if this is your first scope, you'll have a great time seeing Saturn and a few DSOs. Slightly astigmatic eyepieces won't take away from that in the slightest.

In the future, however, you'll be buying more eyepieces and with your focal ratio it would be good to buy the right ones. Of course, it all depends on how much you want to spend. A set of well made Plossls (e.g. the Televues) won't break the bank but will provide good views. One suggestion is you buy one good quality 15 mm Plossl. You can compare the image sharpness in that to the other two and confirm whether or not you want to replace one or both of them.

[pvaz]

If you can, go to a star party or observing night at a local astro society so you can use some gear for free. Nothing better then a try out to see what's best for you.

There are EPs in all price ranges, but until you try some out and have some experience you may not even see the improvements. Usually you notice great improvement when moving from budget EPs to mid range (around 100£ a piece) after that you pay increasingly more for small details. The faster the scope the more you notice the improvements and your scope is quite fast at f/4.7.